Development of a Magnetic Immunosensor to Biomonitor for the Chlorpyrifos Metabolite Trichloropyridinol

Details

• Personal Author:
  Campbell JA ; Lin Y ; Liu G ; Timchalk C
• Description:
  Biological monitoring approaches are being developed using portable analytical systems to quantify dosimetry utilizing readily obtainable body fluids (i.e. blood, urine, and saliva). To assess dosimetry to the insecticide chlorpyrifos (CPF), a fast, simple, and sensitive bioelectrochemical magnetic immunosensing method was developed to measure the metabolite trichloropyridinol (TCP). Under optimal conditions the immunosensor detected a TCP concentration as low as 6 ng L-1, which is 50-fold lower than the reported limit for a commercially available TCP ELISA assay. To establish the utility of the immunosensor, in vivo pharmacokinetic studies were conducted. Rats were given single oral gavage doses (1, 10 or 50 mg/kg) of CPF, and saliva and blood were collected from groups of animals (4/time-point) at 3, 6, and 12 hr post-dosing, and were analyzed for TCP. Trichlorpyridinol was detected in both blood and saliva at all doses and the concentration in blood exceeded saliva; although the kinetics in blood and saliva were comparable. The results from these experiments were then used to further developed a physiologically based pharmacokinetic (PBPK) model for CPF that incorporated a compartment model to describe the blood and saliva time-course of TCP. The computational model adequately simulated the results over the dose ranges evaluated. The model was further used to simulate the blood and saliva TCP concentrations for human dietary CPF exposures in the range of the Allowable Daily Intake (ADI) or Reference Dose (RfD) for CPF (0.01-0.003 mg/kg/day). The simulations suggest that the immunoassay has adequate sensitivity to detect and quantify TCP in blood and saliva at these low exposure levels. However, further studies are needed to fully understand the pharmacokinetics of CPF and TCP, particularly at low environmentally relevant doses. These initial findings suggest that the TCP immunosensor reprsents a novel approach with broad application for evaluating both occupational and environmental exposures to CPF. [Description provided by NIOSH]
• Subjects:
  Animals Biochemistry Blood Energy Metabolism Environmental Exposure Hematologic Tests Insecticides Laboratories Occupational Exposure Occupational Health Safety Urine

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• Keywords:
  Animal-studies Biochemical-analysis Biodynamics Blood-analysis Blood-sampling Environmental-exposure Hemodynamics Laboratory-animals Metabolism Models Occupational-exposure Pharmacodynamics Urinalysis

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• ISSN:
  1096-6080
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Abstract or Summary
• Place as Subject:
  North Carolina ; OSHA Region 10 ; OSHA Region 4 ; Washington
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  86-87
• Volume:
  96
• Issue:
  1
• NIOSHTIC Number:
  nn:20031904
• Citation:
  Toxicologist 2007 Mar; 96(1):86-87
• CAS Registry Number:
  3,5,6-Trichloro-2-pyridinol (CAS RN 6515-38-4) ; Chlorpyrifos (CAS RN 2921-88-2)
• Federal Fiscal Year:
  2007
• NORA Priority Area:
  Agriculture, Forestry and Fishing
• Performing Organization:
  Battelle Pacific Northwest Laboratories
• Peer Reviewed:
  False
• Start Date:
  20060901
• End Date:
  20170831
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:1a9e7c6b859f8231f69ae3c6dd2e5efde166f0f4feb3f745b4e675d309d7b8e36152195a1694f678ecd561e65133ad36c36b9d33ae88a81a1b0b8372ad3e1369
• Download URL:
  https://stacks.cdc.gov/view/cdc/186016/cdc_186016_DS1.pdf
• File Type:
  [PDF - 529.21 KB ]