Abstract
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-μL sample was digested in the presence of a stable-isotope internal standard during a 4-h incubation at 37°C with Pronase™. 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.
Original language | English (US) |
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Pages (from-to) | 2203-2210 |
Number of pages | 8 |
Journal | Rapid Communications in Mass Spectrometry |
Volume | 19 |
Issue number | 16 |
DOIs | |
State | Published - 2005 |
ASJC Scopus subject areas
- Analytical Chemistry
- Spectroscopy
- Organic Chemistry