Gas chromatography/tandem mass spectrometry analysis of alkylresorcinols in red blood cells.
Erythrocyte alkylresorcinols (5-alkyl-1,3-dihydroxybenzenes) are potential biomarkers of wholegrain wheat and rye intake. However, their high-throughput quantitative analysis by gas chromatography/mass spectrometry (GC/MS) is hindered by the time-consuming sample preparation and, more importantly, by interfering compounds that still remain after sample cleanup. In the present work we describe a gas chromatography/tandem mass spectrometry (GC/MS/MS) method for the rapid and reliable quantification of alkylresorcinols in erythrocyte samples. The performance of the GC/MS/MS method is compared with that of GC/MS. The main characteristics of the method are: lower limits of detection: 2-10 microg/L standard solution; lower limits of quantification: 6-30 microg/L standard solution; linearity coefficients: 0.9611-0.9888; linear ranges: 2-20 microg/L in erythrocytes; and intra-day precisions (n = 6): 4-13% at endogenous analyte levels in non-spiked erythrocytes. Tandem mass spectrometry showed greatly improved selectivity over single-stage mass spectrometry in the case of erythrocyte samples, eliminating all interferences detectable in single-stage MS and enabling simple peak integration for quantification. Moreover, increased selectivity resulted in GC separation speeded up by a factor of two, allowing the duplicate analysis of over 40 samples per day. This GC/MS/MS method is suggested as an improved alternative to GC/MS for the quantification of alkylresorcinols in erythrocytes for assessing wholegrain wheat and rye intake.
Nagy
Kornél
K
BioAnalytical Science Department, Nestlé Research Centre, Nestec Ltd., Lausanne, Switzerland. kornel.nagy@rdls.nestle.com
Ross
Alastair B
AB
Fay
Laurent B
LB
Bourgeois
Alexandre
A
Kussmann
Martin
M
D015415:Biomarkers / Q000032:analysis; D002849:Chromatography, Gas / Q000379:methods*; D004435:Eating; D004912:Erythrocytes / Q000737:chemistry*; D006801:Humans; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012118:Resorcinols / Q000032:analysis*; D012434:Secale; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*; D014908:Triticum
D015415:Biomarkers; D012118:Resorcinols