Quantitative determination of mycotoxins in urine by LC-MS/MS

• Published in: Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment Chemistry, analysis, control, exposure & risk assessment, 2010-12, Vol.27 (12), p.1674-1682
• Main Authors: Ahn, J., Kim, D., Kim, H., Jahng, K.-Y.
• Format: Article
• Language: English
• Subjects: Accuracy; Adult; affinity columns; Aflatoxin M1 - metabolism; Aflatoxin M1 - urine; Analytic Sample Preparation Methods; Biological and medical sciences; Biomarkers - urine; Carcinogens - analysis; Carcinogens - metabolism; Child; Chromatography; Chromatography, High Pressure Liquid; Female; Food industries; Food toxicology; Fumonisins - metabolism; Fumonisins - urine; Fundamental and applied biological sciences. Psychology; Glucuronides - urine; Humans; Limit of Detection; liquid chromatography/mass spectrometry (LC/MS); Male; Measurement; Microchemistry - methods; mycotoxins; Mycotoxins - metabolism; Mycotoxins - urine; Ochratoxins - metabolism; Ochratoxins - urine; Pilot Projects; Republic of Korea; Spectrometry, Mass, Electrospray Ionization; Studies; Tandem Mass Spectrometry; Toxicology; Toxins; Urine
• ISSN: 1944-0049; 1944-0057
• DOI: 10.1080/19440049.2010.505201

Naturally occurring mycotoxins are responsible for a wide array of adverse health effects. The measurement of urinary mycotoxin levels is a useful means of assessing an individual's exposure, but the development of sensitive and accurate analytical methods for detecting mycotoxins and their metabolites in urine samples is challenging. Urinary mycotoxins are present in low pg ml -1 concentrations, and the chromatographic identification of their metabolites can be obscured by other endogenous metabolites. We developed an analytical method focused on the selection of two appropriate multiple-reaction monitoring transition for unambiguous identification and quantification of carcinogenic aflatoxin M 1 (AFM 1 ), ochratoxin A (OTA) and fumonisin B 1 , B 2 (FB 1 , FB 2 ) in urine samples from a small volunteer group in a pilot study. AFM 1 , OTA, FB 1 and FB 2 were concentrated selectively, interfering substances were removed using an immunoaffinity column (IAC), and mycotoxins were measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS) in combination with a stable-isotope standard-dilution assay (SIDA). The method was sensitive enough to measure mycotoxins and their metabolites at pg ml -1 levels in urine. The combination of LC-MS/MS and SIDA was critical to distinguishing pseudo-OTα interference from genuine OTα. Twelve urine samples contained OTA ranging from 0.013 to 0.093 ng ml −1 (mean = 0.031 ng ml −1 ). AFM 1 were detected in one sample at a 0.002 ng ml −1 level, while FB 1 and FB 2 were undetectable in all 12 samples. None of the samples in this pilot study contained a detectable level of OTα, despite the presence of OTA, and this may suggest the need for further epidemiological investigation of OTA exposure in the Korean population.