Ionode IJ-Cl User Manual

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Page 1

User maintenance and troubleshooting

GOOD CHEMISTRY

Symptom Possible cause Remedy

Drift Junction blocked Remove and clean sleeve

Membrane unclean or contaminated

Noisy Poor connection

Inaccurate readings or poor reproducibility

to meter Junction not

immersed fully Insufcient

electrolyte or bubble

Contaminated standard(s)

Improperly made standards

Contamination from electrolyte

Temperature differences between calibration and sample measurement

Remove sleeve. Gently polish membrane with P1200 “Wet & Dry”

Check connection

Lower electrode into solution below junction

Rell electrolyte

Make up fresh calibration standards and recalibrate

Recalibrate using freshly made standards

Use 1M potassium nitrate in sleeve

Ensure calibration and sample measurements are done at the same temperature

Warranty

IJ electrodes have a warranty of 12 months from date of purchase. Any electrode found to be faulty due to manufacture within this time will be replaced. Ionode reserves the right to limit or modify product warranty if it is deemed that the electrode has been used in unsuitable applications. Electrodes with broken stems, connectors or cables are not covered by warranty. Electrode life may be reduced in chemically aggressive or abrasive samples and at high temperatures.

Visit www.ionode.com for more information.

Parameter Operating Range

Concentration range 1.8 to 35,000 mg/L Temperature range 0 – 60ºC pH range 2-14 pH Reference Type Double Junction Ag/AgCl/rellable

Images are illustrative only.

Operators Manual

Short-Form

Intermediate Junction Series

IJ-Cl

CHLORIDE

ION SELECTIVE

ELECTRODE

No ISA used Add ISA

Sensitivity to light Perform calibration and

measurements in dark beakers or away from bright light

Sensor materials Polycrystalline solid state

membrane

Body and sleeve Polypropylene/PEEK

Overall length 150mm Barrel diameter 12mm Cable length 1m standard, longer to order.

Maximum 20m

Connector BNC standard, others on request

Page 2

Introduction

This guide contains the basic information for proper use of your Chloride Ion-selective electrode.

Preparation

IJ series electrodes are shipped without sleeve electrolyte, and must be lled prior to use. To ll, hold the electrode by the sleeve and gently ease off the rubber wetting cap. Prepare as follows:

1. 2.

Invert the electrode. Hold the electrode just below the sleeve and with careful rotation and pulling along the axis of the electrode, remove the sleeve. DO NOT BEND.

Fill the annular space with electrolyte to approximately half to three quarter full. 1M potassium nitrate is normally recommended.

Application

The Ionode IJ-Cl Ion selective electrode responds reversibly to Chloride and Silver ions. The limit of detection is 2 x

10-5M Cl

. Use known addition for [Cl-] > 0.1M. Try to avoid exposure of the electrode to direct sunlight, and avoid use in strong reducing agents.

Interfering Ions

Max. ratio of interfering ions/ chloride ion as follows: Hydroxide 80 Ammonium 0.1 Thiosulphate 1 x 10 Bromide 3 x 10 Iodide 5 x 10 Cyanide 2 x 10

-2

-3

-7

Sulphide Must be absent

Cleaning

If the membrane is poisoned by interferences, the surface may be renewed by careful polishing with ne wet-and-dry (P1200 grade). The electrode surface should appear grey or purple-grey with waxy lustre. Always inspect the membrane before use, and clean if necessary. Organic contaminants can be removed with ethanol. DO NOT use the electrode in chlorinated hydrocarbons.Routinely remove the sleeve and replace the potassium nitrate electrolyte.

Electrolyte Replacement

The IJ-Cl has an inbuilt double junction Ag/AgCl with a replaceable sleeve electrolyte. 1M potassium nitrate is suitable for most applications. Please consult Ionode Customer Service if you wish to use a different sleeve electrolyte.

As a guide, add 5ml 1M potassium nitrate to every 50ml of calibration standard or sample.

Calibration Procedure

With your meter set on mV (or on concentration on Ion Meters), calibrate by immersing the electrode in a stirred calibration standard (with added ISA), starting with the lowest concentration rst. Wait for stability, note the potential in mV, and then carefully rinse and blot dry the electrode before repeating with the next highest standard, until all the calibration standards have been measured. When using meters that do not have direct concentration readouts, record the data and graph the potential against log of the Chloride Ion Concentration. The graph should have a slope of approximately -55mV/decade of concentration at 25C.

300

250

200

150

100

Potential mV

1 10 100

Chloride ISE. Typical calibration curve

Concentration PPM

1000

Slide the sleeve back onto the electrode ensuring the black

O-ring is well seated within the electrode body. Do not exert sideways force. Any excess electrolyte will be expelled from the end of the electrode through the ground junction. Ensure there are no air bubbles in the sleeve.Wash off any excess electrolyte before use.

Calibration Standards

Standard solutions of Chloride Ion should preferably bracket the expected measurement range.

The need for ISA (Ionic Strength Adjuster)

It is important to use ISA, so that the Ionic Strength of standards and samples is independent of the concentration of the Chloride Ion. A suitable ISA is potassium nitrate, which is added to both standards and samples.

Sample Measurement

Follow the same basic procedures as calibration, substituting the calibration standard for your sample. It is important to use the same stirring conditions, temperature, etc for best results. Use the same ratio of sample/ISA as used in the calibration step. Read off the concentration from the graph or directly from Ion meters.