Fluorescence quantification of aflatoxin N7-guanine adducts

Details

• Personal Author:
  Groopman JD ; Weaver VM
• Description:
  A method for determining aflatoxin N7-guanine adducts in urine was developed. The hydrolysis procedure was based on 8,9-dihydro-8-(N7- guanyl)-9-hydroxy-aflatoxin-B1 (AFB1-N7-Gua), the N7-guanine adduct of aflatoxin-B1 (1162658) (AFB1). The hydrolysis reaction involved the acidic cleavage of the AFB1-N7-Gua bond for the production of fluorescent derivatives. Urine samples were obtained from two male F344-rats which received a 0.8mg/kg AFB1 injection, and purified by passage through a C18 Sep-Pak cartridge followed by a monoclonal antibody immunoaffinity column. The samples were then injected into a high performance liquid chromatography (HPLC) system utilizing a fluorescence detector set at 365 nanometers (nm) for excitation and 428nm for emission to separate and collect the AFBG peak. The eluate was treated with concentrated hydrochloric-acid at 95 degrees- C for 60 minutes. This hydrolyzed the AFB1G to 8,9-dihydro-8,9- dihydroxyaflatoxin-B1 (AFB1diol). The samples were then quantitated by HPLC with fluorescence detection. Calibration plots of urine samples spiked with AFB1diol standards were linear over the range 39 to 5,000 picograms (pg) hydrolyzed AFB1-N7-Gua. The detection limit was 39pg. The precision obtained for four replicate determinations of urine samples spiked with 39 to 5,000pg AFB1diol expressed as the relative coefficient of variation averaged 11.8%. A well resolved fluorescent peak corresponding to AFB1diol was found. Experiments leading to optimization of the procedure including investigating synchronous fluorescence spectrophotometry (SFS) as an alternative technique were described. The HPLC method was found to be more sensitive than SFS. The authors conclude that the new procedure can detect AFB1G at concentrations that are 100 times lower than available with previously used methods. [Description provided by NIOSH]
• Subjects:
  Biochemistry Chromatography Laboratories Mycoses Nervous System Occupational Health Safety Staff Development Urine
• Keywords:
  Analytical-methods Biochemical-indicators Chromatographic-analysis DNA-adducts Fluorescence-spectrometry Hydroxylation-reactions In-vivo-studies Laboratory-animals Mycotoxins Neoplastic-agents NIOSH-Grant NIOSH-Publication Sample-preparation Training Urinalysis

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• ISSN:
  1055-9965
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  Maryland ; OSHA Region 3
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  3
• Issue:
  8
• NIOSHTIC Number:
  nn:00225420
• Citation:
  Cancer Epidemiol Biomark Prev 1994 Dec; 3(8):669-674
• Contact Point Address:
  Environmental Health Sciences Johns Hopkins University 615 N Wolfe Street Baltimore, MD 21205
• CAS Registry Number:
  Aflatoxin B1 (CAS RN 1162-65-8)
• Federal Fiscal Year:
  1995
• Performing Organization:
  Johns Hopkins University, Baltimore, Maryland
• Peer Reviewed:
  True
• Start Date:
  19910701
• Source Full Name:
  Cancer Epidemiology, Biomarkers & Prevention
• End Date:
  19940630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:f58466e6b1074446d9ca544f1a14523379b7fbd08deee1e44db411ba57a6181a0a6b52958f348b9ea3be4c480ce28995dc717380aaa5e6941ec42211d4edbdd2
• Download URL:
  https://stacks.cdc.gov/view/cdc/204784/cdc_204784_DS1.pdf
• File Type:
  [PDF - 1.02 MB ]