Sampling Intercomparisons for Aldehydes in Simulated Workplace Air

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E. Goelen, M. Lambrechts and F. Geyskens


Abstract

Thirty one laboratories of various EU Member States have participated in two interlaboratory comparisons in order to assess errors of personal sampling methods associated with both the sampling and the analytical steps. In contrast to conventional quality control schemes, this project particularly focuses attention on the sampling and identification step; it is executed by means of sampling exercises and has included discussions on potential sources of error. In a sampling exercise, participants come to a central facility and perform measurements on synthetic workplace air in a laboratory installation. Concentration levels of formaldehyde, acrolein, glutaraldehyde and acetaldehyde between 0.1 and 2 times the limit value for workplace air were prepared at various humidity levels and with acetone, occasionally, as interferent. Sampling times varied from 1–4 h. The related analytical work is performed at the analyst’s own laboratory. The intention is for each participant to determine the observed value of the delivered standard atmosphere using the sampling method of his own choice. Trueness (bias), precision and relative overall uncertainty of each method–laboratory combination is calculated and verified towards compliance with EN 482, which outlines minimum performance criteria. The first challenge involved the precise gas phase generation of the selected analytes in high air flows (up to 300 l min-1) and calculating the true value only by direct reference to primary standards. This was accomplished by modifying the capillary dosage injection technique so that reactive compounds, like low molecular mass aldehydes, could be dosed with the same accuracy and precision as unreactive solvents. A permeation tube with high emission rate was developed for formaldehyde. Up to ten different sampling techniques were evaluated. The measurement methods used by the majority of the participants were based on pumped sampling on silica cartridges (or tubes) and glass fiber filters, coated with 2,4-dinitrophenylhydrazine. It was observed that for formaldehyde, and in some cases for acetaldehyde and glutaraldehyde, the majority of the method–laboratory combinations complied with an overall uncertainty of 30%. The results for acrolein, however, indicated a systematic negative bias, often larger than minus 50% of the true value, caused by the decomposition of the acrolein DNPH derivative in the presence of excess acid and excess DNPH.


References

  1. S. Selim, J. Chromatogr., 1977, 136, 271 CrossRef CAS.
  2. R. K. Beasley, C. E. Hoffman, M. L. Rueppel and J. W. Worley, Anal. Chem., 1980, 52, 1110 CrossRef CAS.
  3. D. Grosjean and G. L. Kok, Anal. Chem., 1982, 54, 1221 CrossRef CAS.
  4. S. B. Tejada, Int. J. Environ. Anal. Chem., 1986, 26, 167 CrossRef CAS.
  5. K. Andersson, G. Andersson, C. Nilsson and J. O. Levin, Chemosphere, 1979, 8, 812 CrossRef.
  6. E. R. Kennedy and R. H. Hill, Anal. Chem., 1982, 54, 1739 CrossRef CAS.
  7. E. R. Kennedy, P. F. O'Connor and Y. T. Gagnon, Anal. Chem., 1984, 56, 2120 CrossRef CAS.
  8. J. O. Levin, K. Andersson, R. Lindahl and C. A. Nilsson, Anal. Chem., 1985, 57, 1032 CAS.
  9. K. Kuwata, M. Uebori and Y. Yamasaki, J. Chromatogr., 1979, 17, 264 CAS.
  10. J. O. Levin, R. Lindahl and K. Andersson, Environ. Sci. Technol., 1986, 20, 1272.
  11. Determination of Formaldehyde Vapours in Air, 3M Occupational Health and Environmental Safety Division, St. Paul, MN, USA Search PubMed.
  12. P. Pfaffli, H. Virtanen, O. Riutta and L. Hayri, in Clean Air at Work: New Trends in Assessment and Measurement for the 1990s, ed. Brown, R. H., Curtis, M. Saunders, K. J., and Vandendriessche, S., Royal Society of Chemistry, 1993, pp. 198–200 Search PubMed.
  13. V. Cocheo, C. Boaretto and P. Sacco, Am. Ind. Hyg. Assoc. J., 1996, 57, 897 CrossRef CAS.
  14. European Committee for Standardization, Assessment of Workplace Exposure—General Requirements for the Performance of Procedures for the Measurement of Chemical Agents, CEN/TC137/European Standard EN 482, Brussels, July 1994 Search PubMed.
  15. E. Goelen, M. Lambrechts, F. Geyskens and R. De Fré, paper presented at the 2nd European Workshop on Mass Spectrometry in Occupational Health, Les Diablerets, Switzerland, June 16–18, 1993.
  16. E. Goelen, F. Geyshens, M. Lambrechts and T. Rymen, Int J. Environ. Anal. Chem., 1992, 47, 217 CrossRef CAS.
  17. E. Goelen, F. Geyskens and M. Lambrechts, Facility for the Generation and Distribution of Aldehyde Atmospheres in Air at Occupational Hygiene Levels, internal VITO report (MIE-DI-95-16), 1995 Search PubMed.
  18. G. O. Nelson, Gas Mixtures—Preparation and Control, Lewis Publishers, Chelsea, 1992 Search PubMed.
  19. Workshop on Possible New Projects in the Field of Workplace Air Monitoring, Brussels, March 25–27, 1991 Search PubMed.
  20. J. O. Levin, R. Lindahl and C. E. M. Heeremans, EUR report, Brussels, 1996.
  21. F. Lipari and S. J. Swarin, J. Chromatogr., 1982, 247, 297 CrossRef CAS.
  22. R. A. Dommer and R. G. Melcher, Am. Ind. Hyg. Assoc. J., 1978, 39, 240 CAS.
  23. European Commission, BCR reference materials, Institute for Reference Materials and Measurements (Joint Research Centre), Geel, 1996.
  24. K. Kuwata, M. Uebori, H. Yamasaki and T. Kuge, Anal. Chem., 1983, 55, 2013 CrossRef CAS.
  25. S. Vainiotalo, K. Matveinen, in Clean Air at Work: New Trends in Assessment and Measurement for the 1990s, ed. Brown, R. H., Curtis, M., Saunders, K. J., and Vandendriessche, S., Royal Society of Chemistry, Cambridge, 1993, pp. 204–205 Search PubMed.
  26. R. R. Arnts and S. B. Tejada, Environ. Sci. Technol., 1989, 23, 1428 CAS.
  27. J. P. Barone, T. H. Walter, in Clean Air at Work: New Trends in Assessment and Measurement for the 1990s, ed. Brown, R. H., Curtis, M., Saunders, K. J., and Vandendriessche, S., Royal Society of Chemistry, Cambridge, 1993, pp. 162–168 Search PubMed.
  28. E. Goelen, F. Geyskens and M. Lambrechts, Ann. Occup. Hyg., 1997, in the press Search PubMed.
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