Analysis of aflatoxin B1-lysine adduct in serum using isotope-dilution liquid chromatography/tandem mass spectrometry

Rapid Commun Mass Spectrom. 2005;19(16):2203-10. doi: 10.1002/rcm.2045.


A method for quantitative analysis of aflatoxin B1-lysine adduct (B1-Lys) in serum by liquid chromatography using tandem mass spectrometry (LC/MS/MS) is presented. The protein in a 250-microL sample was digested in the presence of a stable-isotope internal standard during a 4-h incubation at 37 degrees C with Pronasetrade mark. B1-Lys and the internal standard were extracted using mixed-mode solid-phase extraction cartridges and eluted with 2% formic acid in methanol. Following evaporation and reconstitution, extracts were injected onto a Luna C-18(2) column and eluted with a step gradient of acetonitrile and 0.06% formic acid. The B1-Lys and the internal standard were detected in a positive ionization selective reaction monitoring mode with a ThermoFinnigan TSQ Quantum triple quadrupole mass spectrometer. Calibration curves were linear for concentrations from 0.05-8.0 ng/mL. The method was validated with aflatoxin B1 dosed rat serum diluted to anticipated high and low concentrations. Total imprecision determined from 30 measurements over 15 days was 5.6% and 9.1%, respectively. Recoveries of 78.8 +/- 6.4% for B1-Lys and 85.4 +/- 12.4% for the internal standard were based on the full extraction and reconstitution processes. The method can be used to quantitate B1-Lys at the 0.5 pg/mg albumin level and is suitable for routine analysis.

MeSH terms

  • Aflatoxin B1 / blood*
  • Aflatoxin B1 / isolation & purification
  • Animals
  • Calibration
  • Chromatography, Liquid
  • Humans
  • Isotopes
  • Kinetics
  • Lysine / blood*
  • Lysine / isolation & purification
  • Pronase / metabolism
  • Rats
  • Sensitivity and Specificity
  • Spectrometry, Mass, Electrospray Ionization


  • Isotopes
  • aflatoxin B1-lysine adduct
  • Aflatoxin B1
  • Pronase
  • Lysine