Jenway 6715 User Manual

67 Series

Spectrophotometers

Operating Manual

670 00

IMPORTANT

Please ensure the SD Card is fitted into the socket as detailed in the image below.

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IMPORTANT

Please ensure the SD Card is fitted into the socket as detailed in the image below.

67 Series Spectrophotometer

PC Software

Installation

Insert the 67-Series Software Suite installation CD and select the 67-Series Software Suite icon to open the following screen. Selecting Next commences the

installation. The installation can be aborted by selecting Cancel.

The default installation destination is C:\Program Files\Jenway\67-Series Software Suite\. To select the default destination select Next, to alter the destination select Browse. To review the disk space requirements select Disk Cost. The 67-Series Software Suite can be set up to be used by all users or a single user by checking the appropriate box. To progress the installation select Next, to return to the previous screen select Back, to exit the installation select Exit.

Select Next to commence the installation. To review or change any of the installation parameters select Back. To exit the installation at this stage select Cancel, the software will not be installed if you choose to exit.

When the installation is complete select Close.

The 67-Series Software Suite icon is displayed on desktop

Getting Started

Ensure the PC and spectrophotometer are connected via the USB cable and select the 67-Series Software Suite desktop icon to open the 67-Series Software Suite main screen.

There are three options for accessing saved methods and data: SD, Instrument and PC.

SD allows the user to access methods and data saved on an SD or SD/USB card inserted in the PC.

Selecting SD allows the user to browse through the PC directory for the inserted SD or SD/USB card. Select the required folder, OK and Select SD card as your login source. Entering the Username, Password and selecting Sign-In accesses that specific users methods and data (the Username and Password that are required are the same as when logging into the instrument), the user or password can be saved by ticking the appropriate boxes. Highlighting the required method and selecting Open accesses the saved method.

Data processing for SD is detailed in the Data Processing section.

Note: If the selected location does not contain a valid SD card the error message This

location does not contain a valid SD card will be displayed.

PC allows the user to access methods and data saved to a PC.

Selecting PC allows the user to browse through the PC directory for the desired folder. Select the required folder, OK and Select this folder as your login source. Entering the Username, Password and selecting Sign-In accesses that specific users methods and data (the Username and Password that are required are the same as when logging into the instrument), the user or password can be saved by ticking the appropriate boxes. Highlighting the required method and selecting Open accesses the saved method.

Data processing for PC is detailed in the Data Processing section.

Note: If the selected location does not contain a valid SD card the error message This

location does not contain a valid copied SD card will be displayed.

Instrument allows the user to access data saved to either the internal memory of

the spectrophotometer or a memory card inserted in the spectrophotometer.

Selecting Instrument allows the user to browse through data saved to either the internal memory of the spectrophotometer or a memory card inserted in the spectrophotometer. Select the Check for connected instrument (the default status is Disconnected), whilst searching the Check for connected instrument button updates to read Cancel and the status updates to Searching… when connected the status reads Connected. Choose the desired location of the files from the dropdown bar (the option for Inserted Memory Card is only available if an SD or SD/USB card is inserted in the spectrophotometer) and Select this

location as your login source. Entering the Username and Password and Sign-In

accesses that specific users methods and data (the Username and Password that are

required are the same as when logging into the instrument), the user or password can be saved by ticking the appropriate boxes. To access the required method highlight that line and select Open. Data processing for Instrument is detailed in the Data Processing section.

Note: Whenever the PC and spectrophotometer

are communicating the spectrophotometer’s screen updates to show:

Data Processing

Data processing is the same for the SD, PC and Instrument options. All available methods are displayed in the Open box. Highlighting the required method and

selecting Open opens the method.

Once a method is opened further methods can be opened by selecting the open icon.

Note: Clicking on the column titles alters the order in which the methods are displayed.

Method Name orders the methods alphabetically, Date orders the results in date order, Owner orders the methods by owner type, Method Type orders the methods alphabetically and Internal/Ext orders the methods by the order they appear on the spectrophotometer’s screen.

Photometrics

The photometrics screen displays two tabs Method and Results The Method tab displays the Method Details, Accessories Used (if any) and Information of

the photometric measurement (this information cannot be edited).

The Results tab displays a table of the all the results in the chosen method.

Selecting Filter displays a drop down allowing the results to be filtered by Sample Name, Date/Time, Absorbance or Transmittance values. After inputting the required filter parameters select Apply and the results table will be updated to include the filtered results.

Selecting the print icon opens the Print box. This allows the user to choose the printer, the orientation of the printout and gives the option of printing directly or viewing a Print Preview.

Selecting the copy icon allows the results to be pasted directly into other programmes (e.g. a spreadsheet) for further data manipulation or editing.

Spectrum Scanning

The spectrum screen displays two tabs Methods and Results. The Method tab displays the Method Details, Accessories Used (if any) and Information of

the spectrum scan (this information cannot be edited).

The Results tab displays a table of the all the results in the chosen method. The desired results can be opened by highlighting the required data line and selecting Open, the chosen spectrum is displayed.

Selecting the open icon displays a table of all of the results. Highlighting the desired result and selecting Open will overlay the chosen spectrum.

Holding the cursor over the spectrum trace or the data name will highlight the chosen spectrum and fade any other spectra.

To return to the original spectrum select the open icon and reselect the original data set.

Selecting the area under curve icon displays the following screen. Inputting the required wavelength limits and selecting Apply will calculate the area under the curve to both the tangent and the baseline.

Selecting the peaks and valleys icon displays the following screen. Selecting the required noise filter and Apply will display the both the wavelength values and the absorbances. These values can be displayed on the spectrum, in a table or both by selecting the appropriate boxes. Alternatively selecting a

peak or valley with the cursor will manually label the wavelength and absorbance value.

To exit from the Peaks and Valleys screen select Close.

Selecting the zoom in icon displays the green ‘zoom area’ on the spectrum. Placing this over the desired area and clicking the left mouse button will zoom in to the green highlighted area. This process can be repeated up to four times. Once zoomed in it is possible to return to the previous zoom level by selecting the zoom out icon.

Selecting the print icon opens the Print box. This allows the user to choose the printer, the orientation of the printout, what data is displayed on the printout and gives the option of printing directly or viewing a Print Preview.

Selecting the copy icon allows the results to be pasted directly into other programmes (e.g. a spreadsheet) for further data manipulation or editing.

Multi-Wavelength

The multi-wavelength screen displays two tabs Methods and Results. The Method tab displays the Method Details, Wavelengths, Accessories Used (if any) and

Information of the multi-wavelength measurement.

Selecting the edit sum icon allow the Measurement Mode, Method Security,

Sum, Primary and Secondary wavelengths to be edited.

Measurement Mode can be set as either %T or Absorbance. The Method Security can be set to Private, Public or Read-Only. Sum can be altered to

select one of the three available multi-wavelength equations and the Primary and Secondary Wavelengths can be altered to any recorded wavelength.

After inputting the required parameters select the tick icon to save the changes or the cross icon to cancel

The Results tab displays the data of the multi-wavelength measurement alongside the results of the Sum calculation.

Selecting the open icon allows access to the other results saved in the method.

Selecting the print icon opens the Print box. This allows the user to choose the printer, the orientation of the printout and gives the option of printing directly or viewing a Print Preview.

Selecting the copy icon allows the results to be pasted directly into other programmes (e.g. a spreadsheet) for further data manipulation or editing.

Kinetics

The kinetics screen displays two tabs Methods and Results. The Method tab displays the Method Details, Y-Axis Set-up, Concentration Settings, Run

Settings, Accessories Used (if any) and Information of the kinetics measurement.

The Results tab displays the chosen result.

Selecting the rate of change icon displays the following screen. Entering the required Start Time and End Time automatically updates the Measurement, Mean, X and Y calculations.

Alternatively holding down the left mouse button and dragging over the desired area edits the Start Time and End Time. To return to the original Result tab screen select Hide.

Selecting the copy icon allows the results to be pasted directly into other programmes (e.g. a spreadsheet) for further data manipulation or editing.

Quantitation

The quantitation screen displays two tabs Methods and Results. The Method tab displays the Method Details, Y-Axis Set-up, Accessories Used (if any)

and Information of the kinetics measurement. By clicking on View Calibration Standards the calibration standards used in the result are displayed.

The Results tab displays the calculated concentrations in a table or displays the curve fit.

Selecting the view table icon displays the calculated concentrations in a table

Selecting the view curve fit icon displays the curve fit.

Selecting the copy icon allows the results to be pasted directly into other programmes (e.g. a spreadsheet) for further data manipulation or editing.

Signing Out & Logging In As A Different User

Once all of the required data processing has been completed select the sign out icon to return to the main 67-Series Software Suite screen.

Selecting the sign in icon opens the sign in dialogue box and allows other users to process their data (refer to the Getting Started section for sign in dialogue box details).

Exiting 67-Series Software Suite

Once all of the data has been processed select Exit from the File menu to exit the 67-Series Software Suite.

67 Series Spectrophotometers Models 6700, 6705 & 6715

Operating Manual

670 005/REV D/11-11

Contents

Page Safety 7

Guarantee 8

SECTION 1 - Introduction

1.1 Instrument Description 9

1.2 Instrument Speciﬁcations 10-11

1.3 Good Practice Guidelines 11-12

SECTION 2 - Getting Started

2.1 Unpacking 13-14

2.2 Installation 14-15

2.2.1 Location 14

2.2.2 Supply voltage 14

2.2.3 Mains connections 14

2.2.4 Touch screen functions 15

2.2.5 Toolbar icons 16-20

2.2.6 Rear panel layout 21

2.2.7 Power on and self tests 22

SECTION 3 - Systems of Operation

3.1 Multi-User and Free Operation 23

3.2 Memory Structure 23

3.2.1 Memory selection 23

3.2.2 Memory Hierarchy 24

3.3 Creating Methods 24-25

3.4 File and Data Management 25-26

SECTION 4 - Instrument Settings

4.1 Menu Options 27

4.2 Set Time & Date 27

4.3 User Preferences 27

4.3.1 Adjust User PIN 28

4.3.2 Language 28

4.3.3 Method View Settings 28

4.3.4 Touch Screen Click 29

4.3.5 Brightness 29

4.3.6 Adjust Date & Time 29

4.4 About 30

4.5 Form Feed 30

4.6 Administration Functions 30

4.6.1 Instrument ID 31

4.6.2 Screen Dump 31

4.6.3 Modify Users 31

4.6.3.1 Create New User 32

4.6.3.2 Delete User 32

4.6.3.3 Delete All Users 32

4.6.3.4 Reset User PIN 33

4.7 Memory Manager 33

SECTION 5 - Photometrics Mode

5.1 Principles of Measurement 34

5.2 Free Operation 34-37

Setting Method ID 35 Setting Wavelength 36 Setting Method Security 36 Setting Batch ID 36 Auto Log Settings… 37

5.3 Logged In Measurement 38-41

Creating a New Method 39 Setting Method ID 39 Setting Wavelength 39 Setting Method Security 40 Setting Batch ID 40 Auto Log Settings… 41

File & Data Management 42-43

5.4 Performing Measurements – all users 44

Zeroing the Instrument 44 Measuring the Sample 44

SECTION 6 - Spectrum Mode

6.1 Principles of Measurement 45

6.2 Free Operation 45-52

Setting Method ID 46 Selecting Measurement Mode 46 Setting Wavelengths (Start & End) 47 Selecting Plot Interval 48 Setting Method Security 49 Setting Additional Set-up Parameters using the Toolbar Icons 49-52 Setting Analysis Points 49 Setting Auto-Scale 50 Selecting Plot Colour 50 Selecting Axis Colour 51 Setting Batch ID 51 Setting Graph Data Points 51 Selecting Printer Media 52

Auto Log Settings… 52

6.3 Logged In Measurement 53-56

Creating a New Method 54 Setting Method ID 54 Selecting Measurement Mode 54 Setting Wavelengths (Start & End) 55 Selecting Plot Interval 56 Setting Method Security 56 Setting Additional Set-up Parameters using the Toolbar Icons 57-60 Setting Analysis Points 57 Setting Auto-Scale 58 Selecting Plot Colour 58 Selecting Axis Colour 59 Setting Batch ID 59

Setting Graph Data Points 59 Selecting Printer Media 60 Auto Log Settings… 60 File & Data Management 61-62

6.4 Performing Measurements – all users 63-69 Performing a Scan 63 Peforming a Baseline 63 Scanning the Sample 63-64 Analysing the Scan 64-65 Area Under Curve 65 Co-ordinate Tagging 66 Auto Peak & Valley Tagging 66-67 Obtaining Derivative Spectra 67 Overlaying Scans 68 Adding or Subtracting Spectra 69

SECTION 7 - Multi-Wavelength Mode

7.1 Principles of Measurement 70

7.2 Free Operation 70-75

Setting Method ID 71 Selecting Measurement Mode 72 Selecting Sample Style 72 Setting Method Security 72 Setting Wavelengths 73 Calculations 73 Sum 73-74 Setting Batch ID 74 Selecting Printer Media 74 Auto Log Settings... 75

7.3 Logged In Measurement 76-83

Creating a New Method 77 Setting Method ID 77 Selecting Measurement Mode 77 Selecting Sample Style 78 Setting Method Security 78 Setting Wavelengths 79 Calculations 79 Sum 79-80 Setting Batch ID 80 Selecting Printer Media 80 Auto Log Settings… 81 File & Data Management 82-83

7.4 Performing Measurements – all users 84

SECTION 8 - Kinetics Mode

8.1 Principles of Measurement 85

8.2 Free Operation 85-93

Setting Method ID 86 Setting Wavelength 87 Selecting Measurement Mode 87 Run Settings… 87-89

Setting Run Time 88 Setting Lag Time 88 Setting Start On Level 88 Setting Start Level 89 Setting Method Security 89 Standard 89 Factor 90 Selecting Resolution 90 Selecting Units 90 Setting Auto-Scale 91 Selecting Axis Colour 91 Setting Batch ID 92 Setting Graph Data Points 92 Selecting Printer Media 92 Auto Log Settings… 93

8.3 Logged In Measurement 94-104

Creating a New Method 95 Setting Method ID 95 Setting Wavelength 95 Selecting Measurement Mode 96 Run Settings… 96-97 Setting Run Time 96 Setting Lag Time 97 Setting Start On Level 97 Setting Start Level 97 Setting Method Security 98 Setting Concentration Parameters 98-99 Standard 98 Factor 99 Selecting Resolution 99 Selecting Units 99 Setting Auto-Scale 100 Selecting Axis Colour 100 Setting Batch ID 101 Setting Graph Data Points 101 Selecting Printer Media 101 Auto Log Settings… 102 File & Data Management 103-104

8.4 Performing Measurements – all users 105

SECTION 9 - Quantitation Mode

9.1 Principles of Measurement 106

9.2 Free Operation 106-113

Setting method ID 107 Selecting Measurement Mode 108 Setting Wavelength 108 Selecting Resolution 108 Selecting Units 109 Replicates Setup… 109 Setting Method Security 109 Selecting Calibration Standards 110

Setting Curve Fit 110 Setting Auto Scale 111 Selecting Plot Colour 111 Selecting Axis Colour 112 Setting Batch ID 112 Setting Graph Data Points 112 Selecting Printer Media 113 Auto Log Settings… 113

9.3 Logged In Measurement 114-123

Creating a New Method 115 Setting Method ID 115 Selecting Measurement Mode 115 Setting Wavelength 116 Selecting Resolution 116 Selecting Units 116 Replicates Setup… 117 Setting Method Security 117 Selecting Calibration Standards 118 Setting Curve Fit 118 Setting Auto Scale 119 Selecting Plot Colour 119 Selecting Axis Colour 120 Setting Batch ID 120 Setting Graph Data Points 120 Selecting Printer Media 121 Auto Log Settings… 121 File & Data Management 122-123

9.4 Performing Measurements – all users 124 Post Quantitation Tools 125

SECTION 10 - Fitting & Using Alternative Modules/Accessories

10.1 Integral Printer Unit 126

10.2 Cell Holder Modules 127

10.3 Automatic 8 & 6 Cell Changer Modules 128-132

10.4 Sipper Pump Module 133-139

10.5 Peltier Module 140-142

10.6 Sipper/Peltier Module 143-151

SECTION 11 - Maintenance & Troubleshooting

11.1 General 152

11.2 Light Source Replacement 152-155

Tungsten lamp – Model 6700 153

Flash lamp module – Models 6705/6715 154-155

SECTION 12 - Declaration of Conformity 156-158

Glossary of

Icons 159-161

Safety

This is important information; please read carefully before installing or using this instrument.

1. The 67 Series Spectrophotometers are designed for operation by trained personnel who are

aware of the principles and applications involved. For further help and advice please contact your local distributor, e-mail sales@jenway.com or visit www.jenway.com

2. The spectrophotometer is a sensitive electronic and optical instrument designed for use in a laboratory environment. Careful adherence to the installation instructions must be observed. If in doubt contact a relevant and competent authority for advice before proceeding.

3. In addition to observing the instructions detailed in the Operating Manual and Service Manual for this instrument all installation, operating and service personnel must be aware of, and employ, a safe

system of work.

4. Voltage levels hazardous to life are present in this instrument, for personal safety only trained engineers aware of the risk and avoidance of electric shock should remove protective covers from the

instrument.

5. This instrument is designed for minimal maintenance, which must be carried out carefully following the procedures detailed in this manual. All safety instructions in these procedures, as well as those deﬁned locally for the area or environment where the work is being carried out must be observed.

6. Other than for those items deﬁned in the maintenance procedures herein there are no user serviceable items in this instrument. Removal of covers and attempted adjustment or service by

unqualiﬁed personnel will invalidate any warranty and incur additional charges for repair.

7. Reference should always be made to the Health and Safety Data for any chemicals or reagents used. All available information, advice and warnings on the handling, storage, use and disposal of such must be carefully observed. When not available this data must be requested from the supplier before proceeding in any way.

8. It is important that good laboratory practice is observed when handling samples, chemicals, reagents and ancillary equipment in order to carry out measurement and analysis with this instrument. Suitable safety and personal protective equipment must be used at all times.

9. If it is suspected that safety protection has been impaired in any way, the spectrophotometer must be made inoperative and secured against any intended operation. The fault condition must be reported to the appropriate servicing authority. In all such reports the model number and serial

number of the spectrophotometer must be quoted.

Guarantee

Please read this important guarantee information:

Notwithstanding the description and speciﬁcation(s) of the instruments contained in the Operating Manual, Jenway hereby reserves the right to make changes as it sees ﬁt to the instruments or to any components of the instruments.

This Manual has been prepared solely for the convenience of Jenway customers and nothing in this Manual shall be taken as a warranty, condition or representation concerning the description, merchantability, ﬁtness for purpose, or otherwise of the instruments or components.

The 67 Series spectrophotometers are guaranteed for a period of 3 years from the date of purchase.

Within this period we undertake to supply replacements free of charge for parts that may on examination prove to be defective, provided that the defect is not the result of misuse, accident or negligence.

On all correspondence, please quote the model and serial number in full and/or the sales order number.

Any instrument requiring service under this guarantee should be taken to the supplier through whom it was purchased, or, in the case of difﬁculty, it should be carefully packed in its original packaging and consigned, carriage paid, to us. Jenway takes no responsibility for returned goods damaged in transit.

Returned goods will not be processed without a Returns Authorisation Number.

Call the Service Administrator +44 (0) 1785 810475 for the relevant documentation.

Please write the Returns Number on the outside of any packaging and ensure that a copy of a Decontamination Certiﬁcate is visible.

Please register online www.jenway.com or complete and return the Registration Document by fax or mail.

The Guarantee will be rendered invalid if any speciﬁed non-serviceable parts within the instrument are tampered with (i.e. the monochromator).

SECTION 1 - Introduction

1.1 INSTRUMENT DESCRIPTION

The 67 Series offer a range of unique features and functions to help in the management of methods and data at both individual and multi-user levels.

These units have a specially designed user interface based on a high quality, colour TFT LCD with touch screen technology and QWheel™ support to provide ease-of-use for all operations from set-up to measurement and data handling.

Five main measuring modes are available: Photometrics, Spectrum, Kinetics, Quantitation and

Multi-Wavelength.

The 67 Series have dual memory options that enable you to store settings and data to either internal memory or on a removable SD/Multi-Media memory card. By saving to the removable SD card all settings, methods and results speciﬁc to the user can be retained by the individual, offering additional security and allowing easy transfer of data to a PC for storage, manipulation or off-line review. The SD card can also be used in any similar model, giving complete ﬂexibility to use any available instrument. A simple back-up procedure enables easy transfer of all information from the internal memory to the removable media while quickly enabling a group of instruments to be cloned with identical settings.

It is possible for any user to perform simple measurements (Free Operation) at any time, however, logging-in with your own PIN code will allow you to create methods, change settings or store results. Each method can be designated as Public (for open user access), Read-Only (available for all users as read-only information) or Personal (only accessed through your PIN code).

A number of sampling accessories are available as complete, easily interchangeable modules. These include a Sipper Pump, Sipper/Peltier, Automatic Cell Changer, plus a comprehensive range of passive cuvette and test tube holders, which can be ﬁtted in the single cell holder accessory.

The PC Software supplied enables the transfer of data from the instrument or SD card to the PC with rapid copy and paste into spreadsheets or other computer programmes.

QWheel is a registered trademark of Quantum Research

1.2 INSTRUMENT SPECIFICATIONS

Technical Speciﬁcation

6700 6705 6715

Light Source Tungsten Halogen Xenon Xenon

Spectral Bandwidth 4nm 4nm 1.5nm

Stray Light <0.1% at 340nm <0.05% at 220nm <0.05% at 220nm

Wavelength Range 320-1100nm 190-1100nm 190-1100nm

Common Speciﬁcations

Optics Sealed, MgF Coated, Split Beam

Wavelength Resolution 0.1nm

Wavelength Accuracy ±1.0nm

Wavelength Repeatability ±0.2nm

Photometric Ranges -0.300 to 3.000A & 0 to 199.9%T

Photometric Resolution 0.001A & 0.1%T

Photometric Accuracy ±0.005 at 1A

Photometric Stability <0.001A per hour

Quantitation Range -99999 to +99999

Number of Standards 20 with up to 5 replicates of each

Curve Fit Algorithms Linear, Quadratic and Cubic Functions

Multi-wavelength Data Points Up to 4 wavelengths

Calculations Difference and ratio

Kinetics Time Limits 30 to 9999 seconds

Kinetics Calibration Standard or factor

Scan Speed 1500nm/minute at 0.1nm data steps

Post Scan Analysis Peak/Valley pick, Peak Ratios, Area, Zoom, Wavelength Table,

Removable Media MM/SD Memory Card or SD/USB memory card

Interface USB, Centronics, Analogue

PC Software Supplied on CD-ROM with USB interface cable

Mains Supply 100 to 230V ac 50 or 60Hz

Sample Compartment 150mm (max. height) x 130mm (w) x 210mm (d)

Size 490x390x220mm

Weight 7.5Kg

Derivatives, Smoothing Conﬁguration Secure Multi-User and Free Access

Number of Users 10 + Supervisor

Number of Methods >500 (on internal ﬂash memory or removable media)

Results Storage >500 (on internal ﬂash memory or removable media)

Environmental Operating Conditions:

The 67 Series is designed to work safely under the following conditions:

Temperature 15 to 40ºC

Humidity 0 to 90%RH

Accessory Speciﬁcations

Peltier

Temperature Range: 20 to 50° C or 68 to 122° F

Temperature Resolution: 0.1° C or 1° F

Accuracy: ±0.5° C

Stability: ±0.3° C

Red/Green Window: ±0.5° C

Sipper Pump

Modes:

Continuous Aspiration Flow rate dependent on tube ID. (12ml/min with supplied tube)

Timed aspiration sample/air-gap/wash sample volumes 75µl min / 9.5ml max. segment run time 48 secs max.

Memory Non-volatile

1.3 GOOD PRACTICE GUIDELINES

1. For optimum performance all spectrophotometers should be sited in a clean, dry, dust free

atmosphere. When in use ambient temperature and light levels should remain as constant as possible.

2. Adherence to Standard Operating Procedures (SOP) and Good Laboratory Practice (GLP) should be monitored with regular calibration checks and a suitable Quality Control (QC) programme.

3. The sample chamber lid must be fully closed during measurement and before any readings are recorded or printed.

4. The correct selection of sample containers is imperative for accurate and reproducible results:

a) Check that the material of the sample container is compatible with the wavelengths to be used

for measurement. In general glass can only be used down to 360nm or 320nm depending on quality. Standard plastic cuvettes can be used down to 320nm. Special UV versions can be used down to 260nm. Below this level quartz cuvettes must be used.

b) Plastic disposable cuvettes should be used ONCE only.

c) Glass cuvettes should be thoroughly cleaned after use. Discard when scratches become evident in

optical surfaces.

d) Care should be taken when selecting semi-micro or micro cuvettes. The cuvette window on the inner chamber (the area ﬁlled with sample) must be wider than the aperture in the sample holder or light will reach the detector without passing through the sample. In this case, semi-micro or micro cuvettes with self-screening black surrounds must be used or alternative holders for these cuvettes ﬁtted.

e) Glass test tubes and other sample tubes should be used with care. Where possible, matched tubes should be used and any index mark set to the correct position before measurements are made.

f) Ensure any sample containers used are compatible with the constituents of both the samples and standards they are to hold. Plastic cuvettes are not compatible with organic solvents.

g) All sample containers must be handled with care; by the top and non-optical surfaces only. Any

ﬁnger marks evident must be removed using a suitable cleaning process.

h) Flow-through cuvettes must be selected with care and consideration for the sample type, sample volume, pumping system, rinse, sample and waste handling to be used.

5. Samples and standards should not be stored in open cuvettes or sample containers as evaporation will change the value and lead to staining of the walls which may be irreversible. If stored in stoppered and sealed cuvettes, they should be ﬁlled with little or no air space and the values regularly checked against a reference standard or quality control material.

6. Cold samples should be allowed to equilibrate to ambient temperature before measurement (unless a suitable temperature controlled sample holder is in use). Temperature change during measurement may cause air bubbles to form on the walls of the sample holder. This is a common cause of drift during measurement.

7. In the preparation of samples and standards high grade borosilicate glass and AR grade chemicals and reagents must be used. Good quality deionised water or other suitable solvent must be used for dissolving or diluting samples, chemicals and reagents.

8. All measurements require calibration to a blank, for maximum accuracy this should be prepared with care using the same deionised water or solvent used for dissolving or diluting the sample. Where reagents are added to the sample to produce a colour proportional to its concentration a ‘sample based’ blank should be used. In this case the blank should consist of the sample plus any reagents or chemicals to be used, except those that produce the colour to be measured.

9. Deviations from the Beer-Lambert Law may occur at high and low concentrations giving non-linear response during sample concentration measurements. For all new methods a linear range should be deﬁned by the preparation of a calibration curve. The quantitation mode may be used to construct such a curve against which sample results are automatically measured.

10. Cuvettes and sample holders must be ﬁlled to a minimum level which covers the light path.

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