Losses of dust to walls of cassettes when using the GK2.69 sampler modified for 25 mm diameter filters

Transcription

1 Health and Safety Executive Losses of dust to walls of cassettes when using the GK2.69 sampler modified for 25 mm diameter filters 04/04/18 Peter Stacey, Andrew Thorpe Paul Roberts, HSE s Buxton Laboratory peter.stacey@hsl.gsi.gov.uk

2 The opinions expressed in this presentation are those of the authors alone and do not necessarily reflect the opinions or views of the Health and Safety Executive

3 Exposure by Mass Concentration Measurement

4 Why the GK 2.69? The desire for more sensitivity Limit of detection (LOD) and quantification (LOQ) of traditional techniques (X-ray Diffraction and Infrared) LODs 5-10 µg LOQs µg Part shift sampling at 2.2 l/min at 0.05 mg.m -3 Quarter shift 2 h sampling = 13 µg Half shift 4 h sampling = 26.4 µg Best practice to sample to exceed uncertainty of LOQ or LOD

5 Why the GK 2.69? A comparable performance GK L min -1 PPI 8 8 L min -1 Rascal 9 L min -1 Peter Stacey, Taekhee Lee, Andrew Thorpe, Paul Roberts, Gillian Frost, Martin Harper; Collection Efficiencies of High Flow Rate Personal Respirable Samplers When Measuring Arizona Road Dust and Analysis of Quartz by X-ray Diffraction, The Annals of Occupational Hygiene, Volume 58, Issue 4, 1 May 2014, Pages FSP L min -1

6 Wind tunnel tests

7 How do these compare with the SIMPEDS? - GK 2.69

8 How do these compare? - FSP 10

9 Analytical Approaches Filter diameter HSE MDHS 101

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11 AIR PT Proficiency Testing Results

12 Modification for 25 mm filters

13 For the HSE method MDHS mm filter version Modification for 25 mm diameter filters GK l.min -1

14 Dust losses in respirable sampling filter cassettes Dorr Oliver sampler Soo J-C, Lee T, Kashon M, Kusti M, Harper M. Quartz in Coal Dust Deposited on Internal Surface of Respirable Size Selective Samplers. Journal of occupational and environmental hygiene. 2014;11(12):D215-D219. doi: /

15 Dust losses in respirable sampling filter cassettes Dorr Oliver sampler Losses noted with polystyrene cassettes and coal dust % (on filter cassette surface) GK2.69 cyclone. showed a significantly lower (p < 0.05) internal surface deposit quartz mass fraction for polystyrene cassettes

16 Dust Losses

17 HSE modified GK 2.69 for SIMPEDS filter cassette

18 Dust losses - Tests Calm air chamber Coal dust Arizona Road Dust 3 repeat tests

19 For the HSE method MDHS 101

20 Analytical Issues Infra red Possible loss of sample (coarse dusts) Dark particle absorption X-Ray Diffraction Absorption by matrix depth and by other particles if loading greater than 1 mg Mecchia, M, Pretorius, C, Stacey, P, Mattenklott, M and Incocciati, E. (Eds: Harper M and Lee T), ASTM International. 2013;

21 Absorption correction for XRD XRD Filter holder Sample Aluminium backing plate Silver filter International Organisation for Standardisation. (ISO) Workplace Air Analysis of Respirable Crystalline Silica by X-ray Diffraction Part 1: Direct On-Filter Method, Geneva Switzerland

22 Absorption correction for XRD Silver Sample Quartz Silver filter Silver from blank PVC filter Silver from loaded filter International Organisation for Standardisation. (ISO) Workplace Air Analysis of Respirable Crystalline Silica by X-ray Diffraction Part 1: Direct On-Filter Method, Geneva Switzerland

23 Conclusion GK 2.69 with modification for 25 mm diameter filters at 4 L min -1 Direct on filter approach (MDHS 101) Only use conductive filter cassettes X XRD - Absorption corrections needed for samples > 1 mg

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