Hostname: page-component-77c89778f8-cnmwb Total loading time: 0 Render date: 2024-07-16T10:59:16.339Z Has data issue: false hasContentIssue false

Accuracy and Precision of Analyses for 2,4-D and Picloram in Streamwater by Ten Contract Laboratories

Published online by Cambridge University Press:  12 June 2017

Logan A. Norris*
Affiliation:
For. Sci. Lab., Pac. Northwest For. Range Exp. Stn., U.S. Dep. Agric., For. Serv., Corvallis, OR 97331

Abstract

In a test of laboratory precision and accuracy, streamwater samples fortified with 0, 10, or 50 μg ae/L 2,4-D [(2,4-dichlorophenoxy)acetic acid] and picloram (4-amino-3,5,6-trichloro-2-pyridinecarboxylic acid) were submitted in quadruplicate for residue analysis to 10 laboratories that analyze samples for a fee. Varying amounts of the herbicides were detected by eight laboratories, and two reported no residues. Analyses from most laboratories had a negative bias (ranging from −2 to −92%), although a positive bias appeared in a few instances. Precision was highly variable, the coefficient of variation ranging from 3.4 to 200%. The accuracy range in 19 of 20 cases was ±100 to ±78% for 10 and 50 μg/L 2,4-D and ±100 to ±114% for 10 and 50 μg/L picloram, respectively. Results show that careful selection of contract laboratories and a quality assurance program should be part of monitoring for water contamination with herbicides.

Type
Special Topics
Copyright
Copyright © 1986 by the Weed Science Society of America 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Literature Cited

1. Aspila, K. I., Carron, J. M., and Chan, A.S.Y. 1977. Interlaboratory quality control study of the analysis of water for pesticides. J. Assoc. Off. Anal. Chem. 60:10971104.Google ScholarPubMed
2. Burke, J. A. 1978. The interlaboratory study in pesticide residue analysis. Pages 633642 in Geissbuhler, H., ed. Advances in Pesticide Science, Vol. III, Part 3. Pergamon Press, Elmsford, NY.Google Scholar
3. Burke, J. A. and Corneliussen, P. E. 1975. Quality assurance in the Food and Drug Administration's pesticide residue analytical laboratories. Pages 2531 in Koivistoinen, P. and Koivurinta, J., eds. Environmental Quality and Safety Supplement. Vol. 3. Thieme, Stuttgart.Google Scholar
4. Burse, V. W., Needham, L. L., Korver, M. P., Lapeza, C. R. Jr., Liddle, J. A., and Bayse, D. D. 1983. Assessment of methods to determine PCB levels in blood serum: Interlaboratory study. J. Assoc. Off. Anal. Chem. 66:4045.Google ScholarPubMed
5. Corneliussen, P. E. 1970. Pesticide residues in total diet samples (v), Pestic. Monit. J. 4:8997.Google Scholar
6. Edwards, R. R., Dailey, R. A., and Cruse, H. 1975. Quality assurance in water analysis contracts. J. Am. Water Works Assoc. 67:363366.CrossRefGoogle Scholar
7. Edwards, R. R., Schilling, D. L. Jr., and Rossmiller, T. L. 1977. A performance evaluation of certified water analysis laboratories. J. Water Pollut. Control Fed. 49:17041712.Google Scholar
8. Freese, F. 1960. Testing accuracy. For. Sci. 6:139145.Google Scholar
9. Gunther, F. A. 1980. Interpreting pesticide residue data at the analytical level. Residue Rev. 76:155171.CrossRefGoogle ScholarPubMed
10. Horwitz, W. 1981. Analytical measurements: How do you know your results are right? Adv. Chem. 160:411438.Google Scholar
11. McFarren, E. F., Lishka, R. J., and Parker, J. H. 1970. Criterion for judging acceptability of analytical methods. Anal. Chem. 42:358365.CrossRefGoogle ScholarPubMed
12. Norris, L. A., Lorz, H. W., and Gregory, S. V. 1983. Forest chemicals, U.S. Dep. Agric., For. Serv., Pac. Northwest For. Range Exp. Stn., Gen. Tech. Rep. PNW-149, Portland, OR. 95 pp.Google Scholar
13. Sherma, J. 1981. Manual of analytical quality control for pesticides and related compounds in human and environmental samples. U.S. Environ. Prot. Agency, EPA 600/2-81-059. Research Triangle Park, NC.Google Scholar