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Contents Introduction Synopsis of the method............................................................................................................... 2 Getting started............................................................................................................................ 2 Sampling Loading the filter paper................................................................................................................ 4 Calibration..................................................
Introduction This kit has been designed to comply with MDHS method 52/3 obtainable from the Health & Safety Executive for the testing of Chromic Acid Mist. We strongly recommend reading MDHS 52/3 prior to commencing any sampling. Synopsis of the method Using either a ‘seven hole head’ or - more recently - the ‘IOM sampler’ to hold an alkali treated filter paper, an air sample is taken at 2 litres per minute over the time period of one hour. This can be positioned over a tank with the optional clamp.
Introduction CAUTION! Observe precautions when handling treated filters, and chemicals provided, as they may cause harm to health. We recommend only using stainless steel forceps/tweezers to handle alkali treated filters. Safety Data Sheets are provided at the rear of this manual. www.skcltd.
Sampling Tips and advice on setting up a sampling train (the sample pump with a filter) can be found in the SKC Step by Step guide. The process of loading a filter paper and calibrating this sampling train is similar to the set up required for inhalable dust sampling using an IOM sampler. If you do not have this guide, a free copy can be downloaded from the SKC website at www.skcltd.
Sampling Calibration Assuming an IOM head, SKC Universal pump, and rotameter for calibration. The IOM head with filter is clipped/ held down onto the foam seal on top of the rotameter ensuring a good seal with no leaks. With the toolkit the flow is adjusted by turning the flow adjustment screw. This is located to the bottom left side of the universal sampler and marked ‘flow adjust’. Adjust to to 2L/min. As the screw is turned the float or ball should move up or down inside the rotameter tube.
Analysis The chemicals The kit contains the following chemicals: • 1,5 Diphenylcarbazide 0.125g vial 10 off • Sulphuric acid 0.25 M, 500 ml 1 off • Acetone 250 ml 1 off • De-ionised water 500 ml 1 off Use only 25 mm alkali-treated filter membranes prepared in accordance with MDHS 52/3. 1,5 diphenylcarbazide solution 0.25% w/v is obtained by transferring the contents of one vial (0.125 g) to the 60 ml plastic bottle labelled Diphenylcarbazide 0.25% w/v.
Analysis The apparatus The kit comprises: 1 off 10 off 1 off 1 off 1 off 3 off 1 off 1 off 1 off 1 off 5 off 1 off 1 off 1 off 1 off Alkali treated filter membranes (pack of 24) 1,5 Diphenylcarbazide 0.
Analysis The comparator The Lovibond 2000 comparator fitted with chromium VI comparator disc 26620 covers the range 0-0.1 mg chromium VI per cubic metre of air in steps of: 0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.10 This is suitable for the measurement of 120 litres of sample drawn at 2 litre/minute for 60 minutes. Removing the filter paper for analysis 1. Transfer your sampling system to clean, non hazardous area to perform the analysis. 2.
Analysis 8. Check that comparator colour standards disc Chromium 66200 is inserted. Hold comparator against good north daylight (not fluorescent lighting) and rotate comparator disc until match with ‘sample’ solution is obtained. 9. The value appearing in the window of the comparator is the amount of hexavalent chromium in milligrams per cubic metre (mg/m3) of air based on a sample volume of 120 litres. Note this value. 10. Repeat steps 6 and 7 above using the solution from step 5.
Administration and Next Steps Record keeping Ensure all results obtained from sampling are adequately recorded! This data must be kept for a period of time as defined in H.S.E. guidance, so it is vital to maintain these in an easy-retrieve format. Each sample position should clearly be identified for record purposes and the results of the analysis recorded.
Supplies For supplies and for further advice please contact SKC customer services at: SKC Limited 11 Sunrise Park, Higher Shaftesbury Road, Blandford Forum, Dorset DT11 8ST United Kingdom T: +44 (0) 1258 480188 F: +44 (0) 1258 480184 E: info@skcltd.com W: www.skcltd.com • for items contained in the analysis kit, chemicals, replacement filters, and beakers • for replacement comparator parts • for sampling pumps and heads • for calibration devices • for servicing of pumps and calibrators www.skcltd.
Safety Data Sheets Page 12 www.skcltd.
Safety Data Sheets www.skcltd.
Safety Data Sheets Page 14 www.skcltd.
Safety Data Sheets www.skcltd.
Notes Page 16 www.skcltd.
Notes www.skcltd.
A member of the SKC global group of companies SKC Limited 11 Sunrise Park, Higher Shaftesbury Road, Blandford Forum, Dorset DT11 8ST United Kingdom T: +44 (0) 1258 480188 F: +44 (0) 1258 480184 E: info@skcltd.com W: www.skcltd.
