Method to Biomonitor the Cooked Meat Carcinogen 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine in Dyed Hair by Ultra-Performance Liquid Chromatography–Orbitrap High Resolution Multistage Mass Spectrometry

Abstract

2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is a carcinogenic heterocyclic aromatic amine formed in cooked meat. The use of naturally colored hair containing PhIP can serve as a long-term biomarker of exposure to this carcinogen. However, the measurement of PhIP in dyed hair, a cosmetic treatment commonly used by the adult population, is challenging because the dye process introduces a complex mixture of chemicals into the hair matrix, which interfere with the measurement of PhIP. The high-resolution scanning features of the Orbitrap Fusion™ mass spectrometer were employed to biomonitor PhIP in dyed hair. Because of the complexity of chemicals in the hair dye, the consecutive reaction monitoring of PhIP at the MS3 scan stage was employed to selectively remove the isobaric interferences. The limit of quantification (LOQ) of PhIP was 84 parts-per-trillion (ppt) employing 50 mg hair. Calibration curves were generated in dyed hair matrices and showed good linearity (40 to 1000 pg PhIP/g hair) with a goodness-of-fit regression value r2 > 0.9978. The within-day (between-day) coefficients of variation were 7.7% (17%) and 5.4% (6.1%), respectively, with dyed hair samples spiked with PhIP at 200 and 600 ppt. The levels of PhIP accrued in dyed hair from volunteers on a semi-controlled feeding study who ingested known levels of PhIP were comparable to the levels of PhIP accrued in hair of subjects with natural hair color. The method was successfully employed to measure PhIP in non-dyed and dyed hair biospecimens of participants in a case-control study of colorectal adenoma on their regular diet.

Dose validation of PhIP hair level as a biomarker of heterocyclic aromatic amines exposure: a feeding study

“…We only included subjects who did not use hair dye. We have recently published a method to measure PhIP in dyed hair and reported on a feeding study with well-done meat demonstrating that PhIP hair levels can also be used as a marker of PhIP intake in individuals who color their hair (24).…”

A stable isotope dilution tandem mass spectrometry method of major kavalactones and its applications

“…There were no kavalactones detected in the control samples while all kavalactones were detected in the spiked samples with 6–10 scans across the full width of the peak ( S3 Fig ). Similarly, 10–14 scans were acquired across the full width of the peak at the level of LOQ, suitable for quantitative analysis by the high resolution Orbitrap MS/MS [ 36 ]. The accuracy, precision and reproducibility of the method in different matrices are summarized in Table 1 and S2 – S7 Tables.…”

“…To address these issues, we have developed an ultraperformance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) coupled with the high-resolution Orbitrap, which minimizes the isobaric interferences from the matrix, resulting in increased sensitivity and specificity [ 36 , 37 ]. The method was validated according to the FDA’s guideline for kavain, DHK, methysticin, DHM and desmethoxyyangonin using a deuterium-labeled DHM ( 2 H 2 -DHM, Fig 1 ) as an internal standard.…”

Human Biomonitoring of DNA Adducts by Ion Trap Multistage Mass Spectrometry

“…However, this approach also places the precursor ions into a shallower trapping potential, possibly leading to decreased ion stability and undesired ion losses during ion activation. We observed a need to increase the activation Q from the default value of 0.25 to 0.35 for the fragmentation of PhIP in LIT‐MS; the default value of 0.25 yielded a ten fold lower ion intensity (Guo et al., ). In contrast, no difference in signal was observed when employing activation Q of 0.25 or 0.35 to dissociate the dG adducts of PhIP or other HAAs (Goodenough et al., ; Bessette et al., ).…”