Comparison of immunoassay and high performance liquid chromatography for measuring urinary metabolites of atrazine, metolachlor, and chlorpyrifos from farmers.

Details

• Personal Author:
  Curwin B
• Description:
  Methods: urine samples were collected from 50 participants in a study investigating pesticide exposure among farm families in Iowa. Aliquots from the samples were sent to two different labs and analyzed for metabolites of atrazine (atrazine mercapturate), metolachlor (metolachlor mercapturate) and chlorpyrifos (TCP) by two different analytical methods: immunoassay and high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). HPLC-MS/MS methods tend to be highly specific, but are costly and time consuming. Immunoassay methods are cheaper and faster, but can be less sensitive due to cross reactivity and matrix effects. Three statistical methods were employed to compare the two analytical methods. Each statistical method differed in how the samples that had results below the limit of detection (LOD) were treated. The first two methods involved an imputation procedure and the third method used maximum likelihood estimation (MLE). Results: the immunoassay and HPLC-MS/MS methods were moderately correlated (correlation 0.40-0.49), but the immunoassay methods consistently had significantly higher geometric mean (GM) estimates for each pesticide metabolite. The GM estimates for atrazine mercapturate, metolachlor mercapturate, and TCP by immunoassay ranged from 0.16-0.98 µg/L, 0.24-0.45 µg/L and 13.94-14.13 µg/L, respectively and by HPLC-MS/MS ranged from 0.0015-0.0039 µg/L, 0.12-0.16 µg/L, and 2.91-2.99 µg/L, respectively. Conclusion: for this comparison between two analytical methods with censored data, MLE provided the most meaningful estimates. [Description provided by NIOSH]
• Subjects:
  Biological Factors Energy Metabolism Environmental Monitoring Epidemiology Farmers Hypersensitivity Immune System Insecticides Occupational Exposure Occupational Health Safety Workplace

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• Keywords:
  Work-environment; Exposure-assessment; Exposure-methods; Occupational-exposure; Epidemiology; Biological-factors; Exposure-levels; Statistical-analysis; Farmers; Pesticides-and-agricultural-chemicals; Metabolic-rate; Metabolic-study; Metabolites; Immune-reaction; Immunotoxins; Immunochemistry; Immune-system; Chemical-hypersensitivity
• ISSN:
  1044-3983
• Document Type:
  Text
• Genre:
  Abstract or Summary
• Place as Subject:
  Ohio ; OSHA Region 5
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  DSHEFS - Division of Surveillance, Hazard Evaluations, and Field Studies
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  19
• Issue:
  6
• NIOSHTIC Number:
  nn:20034921
• Citation:
  Epidemiology 2008 Nov; 19(6)(S):S320-S321
• CAS Registry Number:
  Atrazine (CAS RN 1912-24-9) ; Metolachlor (CAS RN 51218-45-2)
• Federal Fiscal Year:
  2009
• NORA Priority Area:
  Agriculture, Forestry and Fishing
• Peer Reviewed:
  False
• Source Full Name:
  Epidemiology; ISEE 20th Annual Conference, Pasadena, California, October 12-16, 2008
• Supplement:
  S
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:7dc847c09aedf140bc731323e8446b4703641ae07d6ad9e7b7238120dab30b8f7dcaa9b938d34d035f87873a0fe7fec262d5d13dcaf290925445e82b6de3b57d
• Download URL:
  https://stacks.cdc.gov/view/cdc/248026/cdc_248026_DS1.pdf
• File Type:
  [PDF - 168.02 KB ]