LaMotte DC1600 User Manual

LaMotte DC1600 Outfit • Code 1785

TABLE OF CONTENTS

Page

Specifications ............................................................................................................................................. 3

General Information................................................................................................................................... 4

General Operating Procedure...................................................................................................................... 5

Chemical Testing........................................................................................................................................ 6

Water Sampling for Chemical Analysis....................................................................................................... 6

Filtration....................................................................................................................................................... 7

An Introduction to Colorimetric Analysis................................................................................................... 7

Reagent Blank.............................................................................................................................................. 7

Colorimeter Tubes........................................................................................................................................ 7

Calibration Curves....................................................................................................................................... 8

Preparing Dilute Standard Solutions............................................................................................................ 9

Standard Additions...................................................................................................................................... 9

Sample Dilution Techniques and Volumetric Measurements..................................................................... 10

Interferences............................................................................................................................................... 10

Stray Light Interferences............................................................................................................................ 10

Testing Procedures

Aluminum.................................................................................................................................................. 11

Ammonia Nitrogen-Low Range................................................................................................................. 13

Ammonia Nitrogen-High Range................................................................................................................ 15

Chlorine-Bromine-Iodine........................................................................................................................... 17

Chlorine Dioxide........................................................................................................................................ 23

Chromium-Hexavalent .............................................................................................................................. 25

Chromium-Total......................................................................................................................................... 27

Copper-Low Range .................................................................................................................................... 31

Copper-High Range.................................................................................................................................... 33

Cyanide ...................................................................................................................................................... 35

Cyanuric Acid ............................................................................................................................................ 37

Fluoride....................................................................................................................................................... 39

Hydrazine.................................................................................................................................................... 41

Hydrogen Peroxide..................................................................................................................................... 43

Iron Bipyridyl.............................................................................................................................................. 45

Iron Phenanthroline................................................................................................................................... 47

Manganese-High Range ............................................................................................................................. 49

Manganese-Low Range............................................................................................................................... 51

Molybdenum-Tiron .................................................................................................................................... 53

Molybdenum-Thioglycolate ....................................................................................................................... 55

Nickel......................................................................................................................................................... 57

Nitrate Nitrogen......................................................................................................................................... 59

Nitrite Nitrogen ......................................................................................................................................... 61

Oxygen, Dissolved...................................................................................................................................... 63

Ozone......................................................................................................................................................... 65

pH............................................................................................................................................................... 67

Phenols....................................................................................................................................................... 69

Phosphate-High Range............................................................................................................................... 71

Phosphate-Low Range................................................................................................................................ 73

Potassium.................................................................................................................................................... 75

Silica-Low Range........................................................................................................................................ 77

Silica-High Range ...................................................................................................................................... 79

Sulfate......................................................................................................................................................... 81

Sulfide......................................................................................................................................................... 83

Tannin........................................................................................................................................................ 85

Turbidity..................................................................................................................................................... 87

Zinc............................................................................................................................................................. 89

61785 • 7/01

LaMOTTE COMPANY

Helping People Solve Analytical Challenges

PO Box 329 • Chestertown • Maryland • 21620 • USA

800-344-3100 • 410-778-3100 (Outside USA) • Fax 410-778-6394

Visit us on the web at www.lamotte.com

SPECIFICATIONS

INSTRUMENT TYPE

Multi-wavelength filter colorimeter _ internal, non-removable filters

READOUT

inch digit LCD; displays 0–100%T

READABLE RESOLUTION

± 1%T

READING STABILITY

± 0.2%T within 5 seconds of turn-on to automatic turn-off

READING INTERVAL

Approximately 30 seconds with automatic turn-off, resettable

MEASUREMENT WAVELENGTHS

1 (420nm), 2 (460nm), 3 (510nm), 4 (530nm), 5 (570nm), 6 (605nm); switch selectable

WAVELENGTH ACCURACY

± 1 nanometers

PHOTOMETRIC ACCURACY

± 0.5%T

SAMPLE CHAMBER

Indexed; accepts 21 mm diameter flat-bottomed test tubes (capped)

SOURCE LAMP

Tungsten filament bulb, 10,000 hour life (est.), spare included, field replaceable

POWER REQUIREMENTS

Battery Operation: Field replaceable 1604 type (9V) Line Operation: 120/220V, 50/60 Hz, 2VA, with optionally-available adapter

DIMENSIONS

(W x D x H) 190 x 140 90 mm

x 5

WEIGHT

x 3

inches

2 lbs.

GENERAL INFORMATION

BAT

LIMITS OF LIABILITY

Under no circumstances shall LaMotte Company be liable for loss of life, property, profits, or other damages incurred through the use or misuse of their products.

PACKAGING AND DELIVERY

Experienced packaging personnel at LaMotte Company assure the adequate protection against normal hazards encountered in transportation of shipments. After the product leaves the manufacturer, all responsibility for its safe delivery is assured by the transportation company. Damage claims must be filed immediately with the transportation company to receive compensation for damaged goods.

Should it be necessary to return the instrument for repair or servicing, pack instrument carefully in suitable container with adequate packing material. Attach a letter to the shipping carton describing the kind of trouble experienced. This valuable information will enable the service department to make the required repairs more efficiently.

EPA COMPLIANCE

The DC1600 Colorimeter is an EPA-Accepted instrument. EPA-Accepted means that the instrument meets the requirements for colorimeters as found in test procedures that are approved for the National Primary Drinking Water Regulations (NPDWR) or National Pollutant Discharge Elimination System (NPDES) compliance monitoring programs. EPA-Accepted instruments may be used with approved test procedures without additional approval.

REPLACING LIGHT BULB

Turn the meter over, making sure the battery compartment is in the upper left corner (This is important). Remove the four screws from the bottom of the colorimeter and remove the base. The burned out light bulb is attached to the small rectangular circuit located just to the right (your right) of the light chamber. Remove the two screws that connect the circuit and SAVE THE BURNED OUT LIGHT BULB. The light bulb must be returned to LaMotte Company for replacement. Make sure the two washers are still in place. Remove the screw in the upper left corner of the colorimeter and detach the replacement circuit. Replace that screw. When fastening the fresh bulb in place, be sure both washers are aligned. Align the base to the meter and replace the four original screws.

NOTE: If the replacement bulb is significantly different from the original bulb, the “Set Blank” control may not have enough range; if so, please call our technical support people for assistance.

REPLACING THE BATTERY

The colorimeter is equipped with a battery check indication, the symbols BAT and ~ on the left hand side of the display, that will be displayed when the battery needs to be replaced. The meter will still provide valid readings, but the readings may drift. Eventually the meter will not have enough power to turn on. To replace the battery, remove the panel on the back of the meter and detach the battery. Replace with a fresh alkaline 1604A type (9V) battery.

Battery polarity (+ & –) must never be reversed, even momentarily. If it is, the instrument will be rendered INOPERABLE, and must be returned to LaMotte Company for repair. This will be considered a non-warranty repair. Use appropriate caution when replacing the battery.

GENERAL OPERATING PROCEDURE

1. Rinse a clean colorimeter tube (0967) with sample water. Fill to the 10 mL line with sample.

2. Select the appropriate wavelength (1 to 7) from the “Select Wavelength” knob. Insert tube into the colorimeter

chamber. (Press firmly on the tube, overcoming the slight resistance, to make sure the tube rests on the bottom of the chamber.)

3. Press the “30 Second Read” button (the BAT and ~ symbols will flash on briefly). Adjust instrument with “Set Blank” control until meter reads exactly 100%T. The instrument is now ready to read an unknown sample.

NOTE: See Battery Replacement section for more information.

4. Perform test outlined in the recommended procedures.

5. Insert sample into the colorimeter and press the “30 Second Read” button. As soon as the reading stabilizes

(usually 5–7 seconds), record the reading.

6. Consult the calibration chart for the corresponding concentration. For example, a reading of 75%T would be found by reading 70%T on the left column of the chart and 5 across the top of the chart. Read down the column until the columns intersect. The value at the intersection represents concentration in parts per million (ppm) or milligrams per liter (mg/L).

TYPICAL CALIBRATION CHART

% T 9 8 7 6 5 4 3 2 1 0

90 80 70 60 50 40 30 20 10

0.04 0.04 0.04 0.05 0.05 0.06 0.06 0.06 0.07 0.07

0.08 0.08 0.08 0.09 0.09 0.10 0.10 0.10 0.11 0.11

0.11 0.12 0.12 0.13 0.13 0.13 0.14 0.14 0.14 0.15

0.15 0.16 0.16 0.16 0.17 0.17 0.18 0.18 0.19 0.19

0.20 0.20 0.21 0.22 0.22 0.23 0.24 0.25 0.26 0.27

0.28 0.30

0.00 0.01 0.01 0.02 0.02 0.02 0.03 0.03

NOTE: The number of decimal places in each number in the calibration chart is provided for interpolation purposes only and does not necessarily reflect the sensitivity of each test.

NOTE: %T readings above the highest %T value on the chart should be interpreted as 0 ppm. For example, on the above chart, readings above 77%T would correspond to 0 ppm. Some tests may have results above 100%T.

CHEMICAL TESTING

WATER SAMPLING FOR CHEMICAL ANALYSIS

TAKING REPRESENTATIVE SAMPLES

The underlying factor to be considered for any type of water sampling is whether or not the sample is truly representative of the source. Some of the ways to properly collect a representative sample are as follows:

Sample as frequently as possible. Collect a large sample or at least enough to conduct whatever tests are necessary. Make a composite sample for the same sampling area. Handle the sample in such a way as to prevent deterioration or contamination before the analysis is performed. Perform analysis for dissolved gases such as dissolved oxygen, carbon dioxide, and hydrogen sulfide immediately at the site

of sampling. These factors, as well as samples for pH, cannot be stored for later examination. Make a list of conditions or observations which may affect the sample. Other considerations for taking representative

samples are dependent upon the source of the sample. Taking samples from surface waters involves different considerations than taking samples from impounded and sub-surface waters.

SAMPLING OF OPEN WATER SYSTEMS

Surface waters, such as those found in streams and rivers, are usually well mixed. The sample should be taken downstream from any tributary, industrial or sewage pollution source. For comparison purposes samples may be taken upstream and at the source of the pollution before mixing.

In ponds, lakes, and reservoirs with restricted flow, it is necessary to collect a number of samples in a cross section of the body of water, and where possible composite samples should be made to ensure representative samples.

To collect samples from surface waters, select a suitable plastic container with a tight fitting screw cap. Rinse the container several times with the sample to be tested, then immerse the container below the surface until it is filled to overflowing and replace the cap. If the sample is not to be tested immediately, pour a small part of the sample out and reseal. This will allow for any expansion. Any condition which might affect the sample should be listed.

Sub-surface sampling is required to obtain a vertical profile of streams, lakes, ponds, and reservoirs at specific depths. This type of sampling requires more sophisticated sampling equipment.

For dissolved oxygen studies, or for tests requiring small sample sizes, a Water Sample Bottle (LaMotte code 1060) will serve as a subsurface or in-depth sampler. This weighted device is lowered to the sampling depth and allowed to rest at this depth for a few minutes. The water percolates into the sample chamber displacing the air which bubbles to the surface. When the bubbles cease to rise, the device has flushed itself approximately five times and it may be raised to the surface for examination. The inner chamber of the sampling device is lifted out and portions of the water sample are carefully dispensed for subsequent chemical analysis.

A Snap-Plunger Water Sampler (LaMotte code 1077) is another “in-depth” sampling device which is designed to collect large samples which can be used for a multitude of tests. Basically, this collection apparatus is a hollow cylinder with a spring loaded plunger attached to each end. The device is cocked above the surface of the water and lowered to the desired depth. A weighted messenger is send down the calibrated line to trip the closing mechanism and the plungers seal the sample from mixing with intermediate layers as it is brought to the surface. A special drain outlet is provided to draw off samples for chemical analysis.

SAMPLING OF CLOSED SYSTEM

To obtain representative samples from confined water systems, such as pipe lines, tanks, vats, filters, water softeners, evaporators and condensers, even different considerations are required because of chemical changes which occur between the inlet and outlet water. One must have a basic understanding of the type of chemical changes which occur for the type of equipment used. Also, consideration should be given to the rate of passage and retaining time for the process water.

Temperature changes play an important part in deciding exactly what test should be performed. Process water should be allowed to come to room temperature, 20–25°C, before conducting any tests.

For drawing off samples from an outlet pipe such as a tap, allow sample to run for several minutes, rinsing the container several times before taking the final sample. Avoid splashing and introduction of any contaminating material.

FILTRATION

When testing natural waters that contain significant turbidity due to suspended solids and algae, filtration is an option. Reagent systems, whether EPA, Standard Methods, LaMotte or any others, will generally only determine dissolved constituents. Both EPA and Standard Methods suggest filtration through a 0.45 micron filter membrane, to remove turbidity, for the determination of dissolved constituents.** To test for total constituents, organically bound and suspended or colloidal materials, a rigorous high temperature acid digestion is necessary.

AN INTRODUCTION TO COLORIMETRIC ANALYSIS

Most test substances in water are colorless and undetectable to the human eye. In order to test for their presence we must find a way to “see” them. The LaMotte colorimeter can be used to measure any test substance that is itself colored or can be reacted to produce a color. In fact a simple definition of colorimetry is “the measurement of color” and a colorimetric method is “any technique used to evaluate an unknown color in reference to known colors”. In a colorimetric chemical test the intensity of the color from the reaction must be proportional to the concentration of the substance being tested. Some reactions have limitations or variances inherent to them that may give misleading results. Many such interferences are discussed with each particular test instruction. In the most basic colorimetric method the reacted test sample is visually compared to a known color standards. However, accurate and reproducible results are limited by the eyesight of the analyst, inconsistencies in the light sources, and the fading of color standards.

To avoid these sources of error, a colorimeter can be used to photoelectrically measure the amount of colored light absorbed by a colored sample in reference to a colorless sample (blank).

Why measure colored light? White light is made up of many different colors or wavelengths of light. A colored sample typical absorbs only one color or one band of wavelengths from the white light. Not much difference could be measured between white light before it passes through a colored sample versus after it passes through. The reason for this is that the one color absorbed by the sample is only a small portion of the total amount of light passing through the sample. However, if we could select only that one color or band of wavelengths of light which the test sample is most sensitive to, we would see a large difference between the light before it passes through the sample and after it passes through.

A colorimeter passes a white light beam through an optical filter which transmits only one particular color or band of wavelengths of light to the photodetector where it is measured. The difference in the amount of colored light transmitted by a colorless sample (blank) and the amount of colored light transmitted by a colored sample is a measurement of the amount of colored light absorbed by the sample. In most colorimetric tests the amount of colored light absorbed is directly proportional to the concentration of the test factor producing the color and the path length through the sample. However, for some tests the amount of colored light absorbed is inversely proportional to the concentration.

The choice of the correct optical filter and therefore the correct color or wavelength of light is important. It is interesting to note that the filter that gives the most sensitive calibration for your test factor is the complimentary color of the test sample. For example, the Nitrate-Nitrogen test produces a pink color proportional to the nitrate concentration in the sample (the greater the nitrate concentration, the darker the pink color). A green filter is used since a pinkish-red solution absorbs mostly green light.

REAGENT BLANK

Some tests will provide greater accuracy if a reagent blank is determined, to compensate for any color or turbidity resulting from the reagents themselves. A reagent blank is performed by running the test procedure on 10 mL of demineralized water. With the reagent blank in the colorimeter chamber, scan the blank then perform the unknown tests as described.

COLORIMETER TUBES

Colorimeter tubes which have been scratched through excess use should be discarded and replaced with new ones. Dirty tubes should be cleaned on both the inside and outside. Fingerprints on the exterior of the tubes can cause excessive light scattering and result in errors. Handle the tubes carefully, making sure the bottom half of the tube is not handled.

LaMotte makes every effort to provide high quality colorimeter tubes. However, wall thicknesses and diameter of tubes may still vary slightly. This may lead to slight variations in results (e.g. if a tube is turned while in the sample chamber, the reading will likely change slightly). To eliminate this error put the tubes into the colorimeter chamber with the same orientation every time.

The tubes that are included with the colorimeter have an index mark to facilitate this.

**LaMotte offers a filtering apparatus: syringe assembly (code 1050) and membrane filters, 0.45 micron, (code 1103).

CALIBRATIONS CURVES

The first step in using a non-LaMotte reagent system with your DC1600 Colorimeter is to create a calibration curve for the reagent system. To create a calibration curve, prepare standard solutions of the test factor and use the reagent system to test the standard solutions with the DC1600 Colorimeter.

Plot the results (in Absorbance or % Transmittance) versus concentration to create a calibration curve. The calibration curve may then be used to identify the concentration of an unknown sample by testing the unknown, reading %T (and calculating absorbance if needed), and finding the corresponding concentration from the curve. You can also determine the linear range of the reagent system. The range of the test is dependent on several factors, including pathlength.

PROCEDURE

1. Prepare 5 or 6 standard solutions of the factor being tested. The concentrations of these standards should be evenly distributed throughout the range of the reagent system, and should include a 0 ppm standard (distilled water). For instance, the solutions could measure 0, 10%, 30%, 50%, 70%, and 90% of the system’s maximum range.

2. Determine the appropriate wavelength for the color produced by the reagent system. The settings for the “Select Wavelength” knob and the corresponding wavelengths are: 1 (420 nm), 2 (460 nm), 3 (510 nm), 4 (530 nm), 5 (570 nm), 6 (605 nm). Set the “Select Wavelength” knob to the setting corresponding to the appropriate wavelength.

3. Rinse a clean colorimeter tube (0967) with unreacted 0 ppm standard. Fill to the 10 mL line with 0 ppm sample. Insert tube into the colorimeter chamber.

4. Press the “30 Second Read” button. Adjust instrument with “Set Blank” control until meter reads exactly 100%T. The instrument is now ready to read an unknown sample.

5. Perform test according to the recommended procedures on each standard solution. Fill a clean colorimeter tube (0967) to the 10 mL line with a reacted sample.

6. Insert reacted sample into the colorimeter chamber and press the “30 Second Read” button. As soon as the reading stabilizes (usually 5–7 seconds), record the reading. Read all other reacted samples and record the results.

7. Plot results on graph paper or computer using any available plotting program. If results are as %T versus concentration, semilog graph paper must be used. Plot the standard solution concentrations on the horizontal, linear axis, and the %T on the vertical, logarithmic axis. If absorbance versus standard solution concentration is to be plotted a simple linear graph paper can be used. Calculate absorbance (A) from %T for each reading [A =

-log(%T/100)]. Plot the standard solution concentration on the horizontal axis, and the absorbance on the vertical axis.

8. After plotting the results, draw a line, or curve, of best fit through the plotted points. The best fit may not connect the points. There should be approximately an equal number of points above the curve as below the curve. Some reagent systems will produce a straight line, while others produce a curve. Many computer spreadsheet programs can produce the curve of best fit by regression analysis of the standard solution data.

A sample of each type of graph appears below:

PREPARING DILUTE STANDARD SOLUTIONS

Standard solutions should be prepared to create a calibration curve. Standard solutions can be prepared by diluting a known concentrated standard by specified amounts. A chart or computer spreadsheet can be created to determine the proper dilutions. Use volumetric flasks and pipets for all dilutions.

1. In Column A – Record the maximum concentration of test as determined by the range and path length.

2. In Column B – Record the percent of the maximum concentration the standard solution will be.

3. In Column C – Calculate the final concentration of the diluted standard solutions by multiplying the maximum

concentration (In Column A) by the % of maximum concentration divided by 100. (C = A x

4. In Column D – Record the final volume of the diluted sample (i.e. volume of volumetric flask).

5. In Column E – Record the concentration of the original standard.

6. In Column F – Calculate the milliliters of original standard required (C x

= F).

A sample chart appears below:

Final

I00

D E C x

Volume

of Standard

Concentration of

Original Standard

A B C = A x

Maximum

concentration

of test

% of Maximum

Concentration

Concentration of Diluted Standard

10.0 ppm 90 9.0 ppm 100 mL 1000 ppm 0.90 mL

10.0 ppm 70 7.0 ppm 100 mL 1000 ppm 0.70 mL

10.0 ppm 50 5.0 ppm 100 mL 1000 ppm 0.50 mL

10.0 ppm 30 3.0 ppm 100 mL 1000 ppm 0.30 mL

10.0 ppm 10 1.0 ppm 100 mL 1000 ppm 0.10 mL

10.0 ppm 0 0 ppm 100 mL 1000 ppm 0 mL

100

mL of Original

Standard Required

= F

STANDARD ADDITIONS

A common method to check the accuracy and precision of a test is by standards additions. In this method a sample is tested to determine the concentration of the test substance. A second sample is then “spiked” by the addition of a known quantity of the test substance. The second sample is then tested. The determined concentration of the spiked sample should equal the concentration of the first plus the amount added with the spike. The procedure can be repeated with larger and larger “spikes.” If the determined concentrations do not equal the concentration of the sample plus that added with the “spike” than a interference may exist.

For example, a 10.0 mL water sample was determined to contain 0.3 ppm iron. To a second 10.0 mL sample add 0.1 mL of 50 ppm iron standard. The concentration of iron due to the “spike” is (0.10 mL * 50 ppm)/10.0 mL = 0.50 ppm. The concentration of iron determined in the spiked sample should be 0.3 + 0.5 = 0.8 ppm iron. (Note: any error due to the increased volume from the “spike” is negligible).

LaMotte offers a line of calibration standards which can be used to generate calibration curves and perform standard additions.

SAMPLE DILUTION TECHNIQUES AND VOLUMETRIC MEASUREMENTS

If a test result exceeds the lower end of the calibration chart for a specific test, you must dilute your sample. Repeat the test to obtain a reading which is in the concentration range for the test. The reading is multiplied by the appropriate dilution factor. If the reading exceeds the high end of the calibration chart, a reagent blank should be run for best results. (NOTE: These comments are not true for colorimetric determination of pH.)

EXAMPLE: Measure 5 mL of the water sample into a graduated cylinder. Add demineralized water until the

cylinder is filled to the 10 mL line. The sample has been diluted by one-half, and the dilution factor is therefore 2. Perform the test procedure, then multiply the resulting concentration by 2 to obtain the test result.

The following table gives quick reference guidelines on dilutions of various proportions. All dilutions are based on a 10 mL volume, so several dilutions will require small volumes of the water sample. Graduated pipets should be used for all dilutions.

SIZE OF SAMPLE

10 mL 0 mL 1

5 mL 5 mL 2

2.5 mL 7.5 mL 4 1 mL 9 mL 10

0.5 mL 9.5 mL 20

If the above glassware is not available, dilutions can be made with the colorimeter tube. Fill the colorimeter tube to the 10 mL line with the sample then transfer it to another container. Add 10 mL volumes of demineralized water to the container and mix. Transfer back 10 mL of the diluted sample to the colorimeter tube and test it. Continue diluting and testing until a reading, which is in the concentration range for the test, is obtained. Be sure to multiply the concentration found by the dilution factor (the number of total 10 mL volumes used).

DEIONIZED WATER TO BRING VOLUME

TO 10 ML

MULTIPLICATION

FACTOR

EXAMPLE: 10 mL of sample is diluted with three 10 mL volumes of demineralized water; the dilution factor is four.

INTERFERENCES

LaMotte reagents systems are designed to minimize most common interferences. Each individual test discusses interferences unique to that test. You should be aware of possible interferences in the water being tested.

The reagent systems also contain buffers to adjust the water sample to the ideal pH for the reaction. It is possible that the buffer capacity of the water sample may exceed the buffer capacity of the reagent system and the ideal pH will not be obtained. If this is suspected, measure the pH of a reacted distilled water reagent blank using a pH meter. This is the ideal pH for the test. Measure the pH of a reacted water sample using the pH meter. If the pH is significantly different from the ideal value, the pH of the sample should be adjusted before testing.

Interferences due to high concentration of the substance being tested for, can be over come by sample dilution.

STRAY LIGHT INTERFERENCE

Normal indoor lighting causes no interference with the DC1600 Colorimeter. Testing in bright sunlight may result in interferences due to stray light. This interference can be eliminated by covering the colorimeter chamber with the black cap when zeroing the meter and reading samples. Turbidimetric determinations (1.e. sulfate, potassium, cyanuric acid and turbidity) are most likely to exhibit a stray light interference. Always check for stray light interferences when you do turbidimetric determinations. Colorimetric test are less likely to have this problem.

To determine if stray light is causing an interference place a reacted sample in the colorimeter chamber. Press the “30 Second Read” button. As soon as the reading stabilizes (usually 5–7 seconds), record the reading. Cover the colorimeter chamber with something (1.e. a hand or any opaque object), if the reading changes then there is an interference. If the reading changes only 1 - 2 % T then the interference is negligible except for the most critical tests. If sample turbidity is causing a stray light interference a filtration may be needed.

ALUMINUM

ERIOCHROME CYANINE R METHOD CODE 3641

QUANTITY CONTENTS CODE

5 g *Aluminum Inhibitor Reagent *7865-C 2 x 120 mL *Aluminum Buffer Reagent *7866-J 120 mL Aluminum Indicator Reagent 7867-J 15 mL Aluminum Complexing Reagent 7868-E 1 Spoon, 0.1 g, plastic 0699 2 Pipets, 1.0 mL, plastic 0354

*WARNING: Reagents marked with a * are considered hazardous substances. Material Safety Data Sheets (MSDS) are supplied for these reagents. For your safety, read label and accompanying MSDS before using.

Aluminum is the third most common element in the earth’s crust, which accounts for its wide appearance in many water supplies. Aluminum exists in water as soluble salts, colloidal compounds, and insoluble compounds. In wastewater that has been treated by alum coagulation it will appear in one or more of the above forms. Properly treated drinking water should have an aluminum concentration below 0.05 mg/L.

APPLICATION: Drinking, surface, and saline water; domestic and industrial wastewater. RANGE: 0 – 0.30 ppm Aluminum METHOD: Aluminum ions buffered to a pH of 6.0 react with Eriochrome Cyanine R dye to produce a

SAMPLE HANDLING & PRESERVATION: Collect sample in acid washed glass or plastic bottle. Analyze as soon as possible.

INTERFERENCES: Fluoride and polyphosphate will interfere. Interference from iron and manganese is eliminated

pink to red complex in proportion to the concentration.

by the addition of an inhibitor.

PROCEDURE

NOTE: For the best possible results, carry a reagent blank through the procedure to compensate for any color which may develop within the reagents. The reagent blank should be treated with 10 drops of Aluminum Complexing Reagent (7868) and the test procedure completed as given in Steps 4-8. Set the Reagent Blank reading to 77%T, which corresponds to 0 ppm aluminum, then continue with unknown sample tests.

1. Rinse a clean colorimeter tube (0967) with sample water. Fill to the 10 mL line with sample.

2. Select setting 4 on “Select Wavelength” knob and press “30 Second Read” button.

3. Insert tube into colorimeter chamber and adjust to 100%T with “Set Blank” knob. This is the 100%T blank.

(See Note.)

4. Remove tube from colorimeter. Use the 0.1 g spoon (0699) to add one measure of *Aluminum Inhibitor Reagent (7865). Cap and mix.

5. Use a 1.0 mL pipet (0354) to add 4 mL of *Aluminum Buffer Reagent (7866). Cap and mix.

6. Use a second 1.0 mL pipet (0354) to add 2 mL of Aluminum Indicator Reagent (7867). Cap and mix contents. Wait

5 minutes for maximum color development.

7. At end of 5 minute waiting period, press “30 Second Read” button and insert tube into colorimeter chamber. Record %T as soon as reading stabilizes.

8. Consult calibration chart to determine aluminum concentration in parts per million (ppm).

DC1600 ALUMINUM CALIBRATION CHART

%T 9 8 7 6 5 4 3 2 1 0

90 80 70 60 50 40 30 20 10 0

0.04 0.04 0.04 0.05 0.05 0.06 0.06 0.06 0.07 0.07

0.08 0.08 0.08 0.09 0.09 0.10 0.10 0.10 0.11 0.11

0.11 0.12 0.12 0.13 0.13 0.13 0.14 0.14 0.14 0.15

0.15 0.16 0.16 0.16 0.17 0.17 0.18 0.18 0.19 0.19

0.20 0.20 0.21 0.22 0.22 0.23 0.24 0.25 0.26 0.27

0.28 0.30

0.00 0.01 0.01 0.02 0.02 0.02 0.03 0.03

AMMONIA NITROGEN ~ LOW RANGE

SALICYLATE METHOD CODE 3659-01

QUANTITY CONTENTS CODE

60 mL *Ammonia #1 *3978-H 10 g *Salicylate #2 *7457-D 5 g *Salicylate #3 *7458-C 1 Spoon, 0.1 g, plastic 0699 1 Spoon, 0.15 g, plastic 0727 1 Pipet, 1.0 mL, plastic 0354

*WARNING: Reagents marked with * are considered hazardous substances. Material Data Safety Sheets (MSDS) are supplied for these reagents. For your safety, read label and accompanying MSDS before using.

APPLICATION: Low concentrations of ammonia in fresh, brackish and salt water. Fresh and salt water

aquariums.

RANGE: 0 – 1.0 ppm Ammonia-Nitrogen METHOD: Salicylate and ammonia react at high pH in the presence of a chlorine donor and an iron

catalyst to form a blue indophenol dye, the concentration of which is proportional to the ammonia concentration in the sample.

SAMPLE HANDLE

& PRESERVATION: Ammonia solutions tend to be unstable and should be analyzed as soon as possible. Samples

can be stabilized by adjusting the pH to less than pH 2 with HCl. The solution should then be neutralized with NaOH before performing the test.

INTERFERENCES: There are few interferences in most natural waters. High concentrations of reducing reagents,

such as hydrazine, react with the chlorine donor and can result in negative interferences. Color and turbidity can also interfere.

PROCEDURE

1. Rinse a clean colorimeter tube (0967) with sample water. Fill to the 10 mL line with sample.

2. Select setting 6 on “Select Wavelength” knob and press “30 Second Read” button.

3. Insert tube into colorimeter chamber and adjust to 100% T with “Set Blank” knob. This is the 100% T blank.

4. Remove tube from colorimeter. Use the 1.0 mL plastic pipet (0354) to add 2.0 mL of *Ammonia #1 (3978). Cap and

mix.

5. Use the 0.15 g spoon (0727) to add two measures of *Salicylate #2 (7457). Cap and mix until dissolved. Wait 1 minute.

6. At end of 1 minute waiting period use 0.1 g spoon (0699) to add two measures of *Salicylate #3 (7458). Cap and shake vigorously for 30 seconds. Wait 12 minutes for maximum color development.

7. At the end of 12 minute waiting period, press “30 Second Read” button and insert tube into colorimeter chamber. Record % T as soon as reading stabilizes.

8. Consult calibration chart to determine ammonia -nitrogen concentration in parts per million (ppm).

DC1600 AMMONIA NITROGEN ~ LOW RANGE CALIBRATION CHART

%T 9 8 7 6 5 4 3 2 1 0

90 80 70 60 50 40 30 20 10 0

0.06 0.07 0.08 0.09 0.10 0.11 0.12 0.13 0.14 0.15

0.17 0.18 0.19 0.20 0.21 0.23 0.24 0.25 0.27 0.28

0.30 0.31 0.33 0.34 0.36 0.38 0.40 0.41 0.43 0.45

0.47 0.50 0.52 0.54 0.57 0.59 0.62 0.65 0.68 0.71

0.75 0.79 0.82 0.87 0.91 0.96 1.02

0.00 0.01 0.02 0.03 0.04 0.04 0.05

AMMONIA NITROGEN ~ HIGH RANGE

NESSLERIZATION METHOD CODE 3642

QUANTITY CONTENTS CODE

30 mL Ammonia Nitrogen Reagent #1 V-4797-G 2 x 30 mL *Ammonia Nitrogen Reagent #2 *V-4798-G 1 Pipet, 1 mL, plastic 0354

Ammonia nitrogen is present in various concentrations in many surface and ground water supplies. Any sudden change in the concentration of ammonia nitrogen in a water supply is cause for suspicion. A product of microbiological activity, ammonia nitrogen is sometimes accepted as chemical evidence of pollution when encountered in natural waters.

Ammonia is rapidly oxidized in natural water systems by special bacterial groups that produce nitrite and nitrate. This oxidation requires that dissolved oxygen be available in the water. Ammonia is an additional source of nitrogen as a nutrient which may contribute to the expanded growth of undesirable algae and other forms of plant growth that overload the natural system and cause pollution.

APPLICATION: Drinking, surface, and saline waters; domestic and industrial wastes. RANGE: 0 – 3.0 ppm Ammonia Nitrogen METHOD: Ammonia forms a colored complex with Nessler’s Reagent in proportion to the amount of

ammonia present in the sample. Rochelle salt is added to prevent precipitation of calcium or magnesium in undistilled samples.

SAMPLE HANDLING & PRESERVATION: Preservation is accomplished by the addition of 2 mL of concentrated H2SO4 at 4°C.

INTERFERENCES: Sample turbidity and color may interfere. Turbidity may be removed by a filtration procedure.

Color interference may be eliminated by adjusting the instrument to 100%T with a sample blank.

PROCEDURE

NOTE: For best results carry a reagent blank through the procedure for greater accuracy. Set the Reagent blank reading to 85%T, which corresponds to 0 ppm ammonia nitrogen, then continue with unknown sample tests.

1. Rinse a clean colorimeter tube (0967) with sample water. Fill to the 10 mL line with sample.

2. Select setting 1 on “Select Wavelength” knob and press “30 Second Read” button.

3. Insert tube into colorimeter chamber and adjust to 100%T with “Set Blank” knob. This is the 100%T blank (See

Note).

4. Remove tube from colorimeter. Add 8 drops of Ammonia Nitrogen Reagent #1 (V-4797). Cap and mix.

5. Use the 1.0 mL pipet (0354) to add 1.0 mL of *Ammonia Nitrogen Reagent #2 (V-4798). Cap and mix. Allow

5 minutes for maximum color development.

6. At end of 5 minute waiting period, press “30 Second Read” button and insert tube into colorimeter chamber. Record %T as soon as reading stabilizes.

7. Consult calibration chart to determine ammonia-nitrogen concentration in parts per million (ppm).

DC1600 AMMONIA NITROGEN ~ HIGH RANGE CALIBRATION CHART

%T 9 8 7 6 5 4 3 2 1 0

90 80 70 60 50 40 30 20 10 0

0.09 0.11 0.12 0.14 0.16 0.17 0.19 0.21 0.23 0.24

0.26 0.28 0.30 0.32 0.34 0.36 0.38 0.40 0.42 0.44

0.46 0.48 0.51 0.53 0.55 0.57 0.60 0.62 0.65 0.67

0.70 0.72 0.75 0.78 0.81 0.84 0.86 0.89 0.93 0.96

0.99 1.02 1.06 1.09 1.13 1.16 1.20 1.24 1.28 1.32

1.37 1.41 1.46 1.51 1.56 1.61 1.67 1.72 1.78 1.84

1.91 1.98 2.05 2.13 2.21 2.30 2.40 2.50 2.61 2.74

2.87 3.02

0.00 0.01 0.03 0.04 0.06 0.07

CHLORINE - BROMINE - IODINE

DPD METHOD CODE 3643

QUANTITY CONTENTS CODE

2 x 100 *DPD #1 Instrument Grade Tablets *6903-J 100 DPD #3 Instrument Grade Tablets 6197-J 15 mL Glycine Solution 6811-E 1 Tablet Crusher 0175

NOTE: To distinguish bromine, free chlorine, total chlorine and combined chlorine, order Glycine Solution (Code 6811-E).

CHLORINE

All water for cities and communities must be disinfected; even waters that come from clean sources, protected watersheds, reservoirs, and deep wells, are commonly disinfected to assure safety. Chlorine is the most commonly used disinfectant for several reasons: it is effective against a wide range of microorganisms, its cost is low, and the methods of applying it have been well developed. If chlorine is present in the water for a few minutes, disease producing bacteria will be destroyed. A number of conditions affect the disinfecting action of chlorine. In municipal systems these can be controlled so that if chlorine is detectable, it can be assumed that bacteria have been killed. The factors that influence the rate of disinfection are temperature, pH, presence of other materials that react with chlorine, time, and the concentrations of the various chlorine combinations that are formed in the water with ammonia and other substances that react with chlorine.

The fact that chlorine can be easily detected and measured makes chlorine a favorite water disinfectant of those concerned with the public safety of water supplies. Chlorine concentrations in the range of 0.1 to 0.4 milligrams per liter are usually maintained in municipal supplies.

Chlorine can be added in the form of chlorine gas, liquid sodium hypochlorite (bleach), granular calcium hypochlorite or as organic chlorine compounds. Chlorine is not present in natural water supplies; if it is present it is the result of chlorination of a water supply or of chlorinated compounds being discharged as waste from industrial operations. The presence of chlorine in concentrations above 0.5 parts per million should be considered evidence of pollution from chlorine treated effluents or from a process in which high concentrations of chlorine are used.

APPLICATION: Drinking, surface, saline waters; swimming pool water; domestic and industrial wastes. RANGE: 0.00 – 4.0 ppm Chlorine METHOD: In the absence of iodide, free available chlorine reacts instantly with DPD to produce a red

color. Subsequent addition of potassium iodide evokes a rapid color response from the combined forms of chlorine (chloramines).

SAMPLE HANDLING & PRESERVATION: Chlorine in aqueous solutions is not stable, and the chlorine content of samples or solutions,

particularly weak solutions, will rapidly decrease. Exposure to sunlight or agitation will accelerate the reduction of chlorine present in such solutions. For best results, start analysis immediately after sampling. Samples to be analyzed for chlorine cannot be preserved or stored.

INTERFERENCE: The only interfering substance likely to be encountered in water is oxidized manganese. The

extent of this interference can be determined by treating a sample with sodium arsenite to destroy the chlorine present so that the degree of interference can be measured.

Iodine and bromine can give a positive interference, but these are not normally present unless they have been added as disinfectants.

FREE CHLORINE

1. Rinse a clean colorimeter tube (0967) with sample water. Fill to the 10 mL line with sample.

2. Select setting 4 on “Select Wavelength” knob and press “30 Second Read” button.

3. Insert tube into colorimeter chamber and adjust to 100%T with “Set Blank” knob. This is the 100%T blank.

4. Remove tube from colorimeter and pour off all but a sufficient amount of sample water to cover a tablet. Add one

*DPD #1 Instrument Grade Tablet (6903). Crush tablet with a tablet crusher (0175), then add water sample until tube is filled to 10 mL line. Cap tube and shake until tablet has dissolved. Solution will turn pink if free chlorine is present.

5. Press “30 Second Read” button and insert tube into colorimeter chamber. Record %T as soon as reading stabilizes. Reading for free chlorine should be made within 30 seconds.

6. Consult calibration chart to determine free chlorine concentration in parts per million (ppm). Do not discard sample if test for total residual chlorine is to be made. If reading is greater than 4.0 ppm, it is recommended that a dilution be made of the sample and the result multiplied by the dilution factor.

COMBINED CHLORINE

1. Add one DPD #3 Instrument Grade Tablet (6197) to sample from Step 5 above. Crush tablet with tablet crusher (0175). Cap tube and shake until tablet dissolves. An increase in color over Step 5 represents combined chlorine.

2. Press “30 Second Read” button and insert sample into colorimeter chamber. Record %T as soon as reading stabilizes.

3. Consult calibration chart to determine total chlorine concentration in parts per million (ppm). Subtract free chlorine

reading from total chlorine reading to obtain concentration of combined chlorine. If reading is greater than 4.0 ppm, it is recommended that a dilution be made of the sample and the result multiplied by the dilution factor.

DC1600 FREE AND TOTAL CHLORINE CALIBRATION CHART

%T 9 8 7 6 5 4 3 2 1 0

90 80 70 60 50 40 30 20 10 0

0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09

0.10 0.11 0.12 0.13 0.14 0.15 0.16 0.18 0.19 0.20

0.21 0.22 0.24 0.25 0.26 0.28 0.29 0.30 0.32 0.33

0.34 0.36 0.37 0.39 0.41 0.42 0.44 0.45 0.47 0.49

0.51 0.52 0.54 0.56 0.58 0.60 0.62 0.64 0.66 0.68

0.71 0.73 0.75 0.78 0.80 0.83 0.85 0.88 0.91 0.94

0.96 1.00 1.03 1.06 1.09 1.13 1.16 1.20 1.24 1.28

1.32 1.37 1.41 1.46 1.51 1.57 1.62 1.68 1.74 1.81

1.88 1.95 2.03 2.12 2.21 2.31 2.42 2.54 2.67 2.82

2.98 3.17 3.39 3.65 3.96

BROMINE

APPLICATION: Drinking, surface, saline waters; swimming pool water; domestic and industrial waters and

wastes.

RANGE: 0 – 10 ppm Bromine METHOD: In buffered sample bromine reacts with diethyl-p-phenylene diamine (DPD) to produce a

SAMPLE HANDLING & PRESERVATION: Bromine in aqueous solutions is not stable, and the bromine content of samples or solutions,

INTERFERENCE: The only interfering substance likely to be encountered in water is oxidized manganese. The

pink-red color in proportion to the concentration of bromine present.

particularly weak solutions, will rapidly decrease. Exposure to sunlight or agitation will accelerate the reduction of bromine present in such solutions. For best results start analysis immediately after sampling. Samples to be analyzed for bromine cannot be preserved or stored.

extent of this interference can be determined by treating a sample with sodium arsenite to destroy the bromine present so that the degree of interference can be estimated.

Iodine and chlorine can also interfere, but these are not normally present unless they have been added as disinfectants.

PROCEDURE

A. BROMINE (NO CHLORINE)

1. Rinse a clean colorimeter tube (0967) with sample water. Fill to the 10 mL line with sample.

2. Select setting 4 on “Select Wavelength” knob and press the “30 Second Read” button.

3. Insert tube into colorimeter chamber and adjust to 100%T with the “Set Blank” knob. This is the 100%T blank.

4. Remove tube from the colorimeter. Pour out all but a sufficient amount of sample water to cover a tablet. Add one

*DPD #1 Instrument Grade Tablet (6903). Crush tablet with tablet crusher (0175), then add sample water until tube is filled to 10 mL line. Cap tube and shake until tablet is dissolved. Solution will turn pink if bromine is present.

5. Press “30 Second Read” button and insert tube into colorimeter chamber. Record %T as soon as reading stabilizes.

6. Consult calibration chart to determine bromine concentration in parts per million (ppm).

B. BROMINE IN THE PRESENCE OF CHLORINE

1. Rinse a clean colorimeter tube (0967) with sample water. Fill to the 10 mL line with sample.

2. Select setting 4 on “Select Wavelength” knob and press “30 Second Read” button.

3. Insert tube into colorimeter chamber and adjust to “100”%T with the “Set Blank” knob. This is the 100%T blank.

4. Rinse a second clean colorimeter tube (0967) with sample water. Fill to the 10 mL line with sample. Add 5 drops of

Glycine Solution (6811). Cap and mix.

5. Remove 100%T blank from colorimeter. Pour out all of the sample water. To this tube add just enough of Glycine treated sample (Step 4) to cover a tablet. Add one *DPD#1 Instrument Grade Tablet (6903). Crush tablet with a tablet crusher (0175). Add all remaining Glycine-treated sample. Cap tube and shake until tablet dissolves. Solution will turn pink if bromine is present.

6. Press “30 Second Read” button, and insert sample into colorimeter chamber. Record %T as soon as reading stabilizes.

7. Consult calibration chart to determine bromine concentration in parts per million (ppm). Record as Reading BR.

C. FREE AVAILABLE, TOTAL AVAILABLE AND COMBINED CHLORINE IN THE PRESENCE OF BROMINE

NOTE: Combined chlorine is not affected by the presence of bromine, so the calculation is the same as when only chlorine is present.

1. Perform the test for free and combined chlorine as previously described.

2. Perform the test for bromine in the presence of chlorine.

3. Calculations:

Residual Bromine (ppm) = Reading BR

Free Chlorine in the Presence of Bromine =

Total Chlorine in the Presence of Bromine =

Combined Chlorine in the Presence of Bromine =

DC1600 BROMINE CALIBRATION CHART

%T 9 8 7 6 5 4 3 2 1 0

90 80 70 60

40 30 20 10 0

0.10 0.12 0.13 0.15 0.17 0.19 0.21 0.23 0.25 0.27

0.29 0.31 0.33 0.35 0.37 0.40 0.42 0.44 0.47 0.49

0.51 0.54 0.56 0.59 0.61 0.64 0.67 0.69 0.72 0.75

0.78 0.81 0.84 0.87 0.90 0.93 0.96 1.00 1.03 1.06

1.10 1.14 1.17 1.21 1.25 1.29 1.33 1.37 1.42 1.46

1.50 1.55 1.60 1.65 1.70 1.75 1.80 1.86 1.91 1.97

2.03 2.09 2.16 2.23 2.30 2.37 2.44 2.52 2.60 2.68

2.77 2.86 2.96 3.06 3.16 3.27 3.39 3.51 3.64 3.78

3.93 4.08 4.25 4.43 4.63 4.84 5.07 5.32 5.60 5.92

6.27 6.67 7.14 7.70 8.38 9.24 10.40

Free Chlorine − 0.45 (Reading BR) Total Chlorine − 0.45 (Reading BR) Total Chlorine − Free Chlorine

IODINE

APPLICATION: Drinking, surface, saline waters; swimming pool water; domestic and industrial wastes. RANGE: 0 - 15.0 ppm Iodine METHOD: In a buffered sample iodine reacts with diethyl-p-phenylene-diamine (DPD) to produce a

pink-red color in proportion to the concentration of iodine present.

SAMPLE HANDLING & PRESERVATION: Iodine in aqueous solutions is not stable, and the iodine content of samples or solutions,

particularly weak solutions, will rapidly decrease. Exposure to sunlight or agitation will accelerate the reduction of iodine present in such solutions. For best results start analysis immediately after sampling. Samples to be analyzed for iodine cannot be preserved or stored.

INTERFERENCE: The only interfering substance likely to be encountered in water is oxidized manganese. The

extent of this interference can be determined by treating a sample with sodium arsenite to destroy the chlorine present so that the degree of interference can be measured.

Chlorine and bromine can give a positive interference, but these are not normally present unless they have been added as disinfectants.

PROCEDURE

1. Rinse a clean colorimeter tube (0967) with sample water. Fill tube to the 10 mL line with sample.

2. Select setting 4 on “Select Wavelength” knob and press “30 Second Read” button.

3. Insert tube into colorimeter chamber and adjust to 100%T with “Set Blank” knob. This is the 100%T blank.

4. Remove tube from colorimeter. Pour off all but a sufficient amount of sample water to cover a tablet. Add one *DPD

#1 Instrument Grade Tablet (6903). Crush tablet with tablet crusher (0175). Add sample water until tube is filled to 10 mL line. Cap and shake until tablet dissolves. Solution will turn pink if iodine is present.

5. Press “30 Second Read” button and insert tube into colorimeter chamber. Record %T as soon as reading stabilizes.

6. Consult calibration chart to determine iodine concentration in parts per million (ppm).

DC1600 IODINE CALIBRATION CHART

%T 9 8 7 6 5 4 3 2 1 0

90 80 70 60 50 40 30 20 10 0

0.13 0.17 0.21 0.25 0.29 0.32 0.36 0.40 0.44 0.49

0.53 0.57 0.61 0.66 0.70 0.75 0.79 0.84 0.88 0.93

0.98 1.03 1.08 1.13 1.18 1.23 1.29 1.34 1.39 1.45

1.51 1.56 1.62 1.68 1.74 1.81 1.87 1.93 2.00 2.07

2.13 2.20 2.28 2.35 2.42 2.50 2.58 2.66 2.74 2.82

2.91 2.99 3.08 3.17 3.27 3.36 3.46 3.57 3.67 3.78

3.89 4.01 4.12 4.25 4.37 4.50 4.64 4.78 4.92 5.08

5.23 5.40 5.57 5.74 5.93 6.13 6.33 6.55 6.78 7.02

7.27 7.54 7.83 8.14 8.47 8.83 9.22 9.65 10.12 10.64

11.23 11.89 12.66 13.56 14.65

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CHLORINE DIOXIDE

DPD METHOD CODE 3644

QUANTITY CONTENTS CODE

100 *DPD #1 Instrument GradeTablets *6903-J 15 mL Glycine Solution 6811-E 1 Tablet Crusher 0175

Chlorine dioxide is used as a substitute for and an adjunct to chlorine in water treatment. It is better than chlorine in eliminating taste and odor in certain cases. Chlorine dioxide, unlike chlorine, does not produce carcinogenic chlorinated organic compounds when reacted with organic materials. A disadvantage is the higher cost of producing chlorine dioxide compared to chlorine.

APPLICATION: Drinking and pool waters; domestic and industrial wastewater.

RANGE: 0 – 7.0 ppm Chlorine Dioxide METHOD: Chlorine dioxide reacts with DPD to form a red color in proportion to the concentration.

SAMPLE HANDLING & PRESERVATION: Test as soon as possible to avoid loss of chlorine dioxide.

INTERFERENCE: Chlorine interference is eliminated by the addition of glycine to the sample before the

indicator.

PROCEDURE

1. Rinse a clean colorimeter tube (0967) with sample water. Fill to 10 mL line with sample.

2. Select setting 4 on “Select Wavelength” knob and press “30 Second Read” button.

3. Insert tube into colorimeter chamber and adjust to 100%T with “Set Blank” knob. This tube is the 100%T blank.

4. Remove tube from colorimeter. Pour out all but a sufficient amount of sample water to cover tablet. Add 5 drops of

Glycine Solution (6811).

5. Add one *DPD #1 Instrument Grade Tablet (6903). Crush tablet with tablet crusher. Cap and shake until tablet dissolves. Fill to 10 mL line with sample water. Solution will turn pink if chlorine dioxide is present.

6. Press “30 Second Read” button and insert tube into colorimeter chamber. Record %T as soon as reading stabilizes. The reading should be made within 30 seconds.

7. Consult calibration chart to determine chlorine dioxide concentration in parts per million (ppm).

DC1600 CHLORINE DIOXIDE CALIBRATION CHART

%T 9 8 7 6 5 4 3 2 1 0

90 80 70 60 50 40 30 20 10 0

0.16 0.18 0.20 0.22 0.24 0.26 0.28 0.30 0.32 0.35

0.37 0.39 0.41 0.44 0.46 0.48 0.51 0.53 0.56 0.59

0.61 0.64 0.67 0.70 0.72 0.75 0.78 0.81 0.85 0.88

0.91 0.94 0.98 1.01 1.05 1.08 1.12 1.16 1.20 1.24

1.28 1.32 1.37 1.41 1.46 1.51 1.55 1.61 1.66 1.71

1.77 1.82 1.88 1.94 2.01 2.07 2.14 2.21 2.29 2.36

2.44 2.53 2.61 2.70 2.80 2.90 3.01 3.12 3.24 3.37

3.50 3.64 3.79 3.96 4.14 4.33 4.54 4.77 5.02 5.31

5.63 6.00 6.42 6.93

0.00 0.02 0.03 0.05 0.07 0.09 0.11 0.12 0.14

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CHROMIUM (HEXAVALENT)

DIPHENYLCARBOHYDRAZIDE METHOD CODE 3645

QUANTITY CONTENTS CODE

10 g *Chromium Reagent Powder *V-6276-D 1 Spoon, 0.1 g, plastic 0699 1 Filter Paper 0465-H 1 Funnel, 20 mL 2-2135

Chromium may be present in water containing waste from industries such as metal plating, or in overflow water from large air conditioning units where chromate compounds are frequently added to cooling water to control corrosion. It is considered to be a toxic chemical and, if present in an amount of over 0.5 ppm, is evidence of contamination from untreated or incompletely treated industrial waste.

Chromium is one of a class of heavy metals found in the bottom muds of polluted bodies of waters. Certain shellfish are capable of concentrating this element, endangering the health of its ultimate consumer, human or animal.

APPLICATION: Drinking, surface, & saline waters; domestic and industrial wastewaters. RANGE: 0 – 1.0 ppm Chromium METHOD: Hexavalent chromium reacts with 1,5 diphenylcarbohydrazide under acidic conditions to form

a red-purple color in proportion to the amount of chromium present.

SAMPLE HANDLING & PRESERVATION: Analysis for chromium should be made as quickly as possible after sample collection since

storage in glass or plastic containers may result in low chromate values.

INTERFERENCES: High concentrations of mercurous and mercuric ions may impart a blue color to the chromium

determination. Iron and vanadium in concentrations above 1 mg/L may result in a yellow color. However, the vanadium color becomes negligible 10 minutes after the addition of diphenylcarbohydrazide.

PROCEDURE

1. Rinse a clean colorimeter tube (0967) with sample water. Fill to the 10 mL line with sample.

2. Select setting 4 on “Select Wavelength” knob and press “30 Second Read” button.

3. Insert tube into colorimeter chamber and adjust to 100%T with “Set Blank” knob. This is the 100%T blank.

4. Remove tube from colorimeter chamber. Use the 0.1g spoon (0699) to add one measure of *Chromium Reagent

Powder (V-6276). Cap and shake until powder dissolves. Wait 2 or 3 minutes for full color development. NOTE: Highly buffered waters may give poor results and require a more careful pH adjustment. Order the Chromium

pH Adjustment Package, Code 2087. NOTE: During waiting period, fold a piece of filter paper (0465) in half then half again to form a cone, and fit into

the funnel (2-2135).

5. At the end of 2-3 minute waiting period, filter sample into a clean colorimeter tube. Insert this tube into colorimeter chamber and press “30 Second Read” button. Record %T as soon as reading stabilizes.

6. Consult calibration chart to determine hexavalent chromium concentration in parts per million (ppm). NOTE: To convert result to ppm chromate (CrO4

(Na2CrO4), multiply by 3.12.

DC1600 CHROMIUM (HEXAVALENT) CALIBRATION CHART

%T 9 8 7 6 5 4 3 2 1 0

100

90 80 70 60 50 40 30 20 10 0

0.016 0.019 0.022 0.026 0.029 0.032 0.036 0.040 0.043 0.047

0.050 0.054 0.058 0.062 0.065 0.069 0.073 0.077 0.081 0.085

0.089 0.094 0.098 0.102 0.106 0.111 0.115 0.120 0.124 0.129

0.134 0.139 0.143 0.148 0.153 0.158 0.164 0.169 0.174 0.180

0.185 0.191 0.197 0.202 0.208 0.214 0.221 0.227 0.233 0.240

0.247 0.253 0.260 0.267 0.275 0.282 0.290 0.298 0.306 0.314

0.322 0.331 0.340 0.349 0.358 0.368 0.378 0.388 0.399 0.410

0.421 0.433 0.445 0.458 0.471 0.484 0.499 0.514 0.529 0.546

0.563 0.581 0.600 0.621 0.643 0.666 0.691 0.719 0.748 0.781

0.817 0.857 0.903 0.956 1.019

-2

), multiply by 2.23. To convert result to ppm sodium chromate

0.000 0.003 0.006 0.009 0.012

CHROMIUM

HEXAVALENT, TRIVALENT & TOTAL

DIPHENYLCARBOHYDRAZIDE METHOD CODE 3698

QUANTITY CONTENTS CODE

60 mL *Sulfuric Acid, 5N *7681-H 10 g *Chromium Reagent Powder *V-6276-D 15 mL *Sodium Azide, 5% *7683-E 30 mL Potassium Permanganate, 0.5% 7682-G 60 mL Deionized Water 5115PT-H 1 Pipet, plain, glass, w/cap 0341 1 Pipet, 1.0mL, plastic 0354 1 Pipet, plain, plastic 0352 1 Spoon, 0.1 g, plastic 0699 1 Graduated Cylinder, 50 mL, glass 0418 1 Flask, Erlenmeyer, 125 mL, glass 0431 1 Test tube holder 1113 1 Filter Paper 0465 1 Funnel, plastic 0459

A toxic chemical, chromium is found in two forms in the water; trivalent chromium (Cr+3) and hexavalent chromium (Cr+6). Chromium enters the water from industrial waste, including large air conditioning units where it may be used to control corrosion, or metal finishing plants. Trivalent chromium is more toxic than hexavalent chromium. Levels greater than 0.5 ppm indicate improperly treated industrial waste. It is important to maintain chromium levels at or below 0.5 ppm, because clams and other shellfish will store chromium in their systems, accumulating levels which may be dangerous to the consumer, whether human or animal.

APPLICATION: Drinking, surface, & saline water; domestic and industrial waste RANGE: 0 – 1.0 ppm METHOD: The trivalent chromium is converted to hexavalent chromium by permanganate under acidic

SAMPLE HANDLING

& PRESERVATION: Analysis for chromium should be made as quickly as possible after sample collection since

INTERFERENCES: High concentrations of mercurous and mercuric ions may interfere.

conditions. Hexavalent chromium reacts with 1,5 diphenylcarbohydrazide under acidic conditions to form a red-purple color in proportion to the amount of chromium present.

storage in glass or plastic containers may result in low chromate values.

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