An optimized and validated SPE-LC–MS/MS method for the determination of caffeine and paraxanthine in hair

Abstract

Caffeine is the probe drug of choice to assess the phenotype of the drug metabolizing enzyme CYP1A2. Typically, molar concentration ratios of paraxanthine, caffeine's major metabolite, to its precursor are determined in plasma following administration of a caffeine test dose. The aim of this study was to develop and validate an LC-MS/MS method for the determination of caffeine and paraxanthine in hair. The different steps of a hair extraction procedure were thoroughly optimized. Following a three-step decontamination procedure, caffeine and paraxanthine were extracted from 20 mg of ground hair using a solution of protease type VIII in Tris buffer (pH 7.5). Resulting hair extracts were cleaned up on Strata-X ™ SPE cartridges.All samples were analyzed on a Waters Acquity UPLC ® system coupled to an AB SCIEX API 4000™ triple quadrupole mass spectrometer. The final method was fully validated based on international guidelines. Linear calibration lines for caffeine and paraxanthine ranged from 20 to 500 pg/mg. Precision (%RSD) and accuracy (%bias) were below 12 and 7 %, respectively. The isotopically labeled internal standards compensated for the ion suppression observed for both compounds. Relative matrix effects were below 15 %RSD. The recovery of the sample preparation procedure was high (> 85 %) and reproducible. Caffeine and paraxanthine were stable in hair for at least 644 days. The effect of the hair decontamination procedure was evaluated as well. Finally, the applicability of the developed procedure was demonstrated by determining caffeine and paraxanthine concentrations in hair samples of ten healthy volunteers. The optimized and validated method for determination of caffeine and paraxanthine in hair proved to be reliable and may serve to evaluate the potential of hair analysis for CYP1A2 phenotyping.

Caffeine content in newborn hair correlates with maternal dietary intake

“…To the best of our knowledge, this study is the first to show that caffeine and its major metabolite paraxanthine are measurable in newborn hair by the HRMS method, and that these levels correlate positively with the approximated maternal caffeine intake during the last trimester of pregnancy. First, this confirms that caffeine diffuses from maternal to fetal circulation through the placenta and is incorporated into the growing fetal hair [8,12]. This indicates that long-term cumulative fetal exposure can be measured in a newborn's hair.…”

“…Most exposure agents, including caffeine and paraxanthine, pass through the placenta, affect fetal circulation, and stably incorporate into the growing fetal hair. Thus, newborn hair represents cumulative fetal exposure during the third trimester of pregnancy, similarly to how adult hair samples represent cumulative exposure during the preceding months in adults [11,12]. Caffeine is mainly metabolized to paraxanthine and other isomers as theobromine and theophylline in the liver by the CYP1A2 enzyme.…”

Multi-Spheres Adsorptive Microextraction (MSAμE)—Application of a Novel Analytical Approach for Monitoring Chemical Anthropogenic Markers in Environmental Water Matrices

“…As can be observed, the proposed methodology revealed recovery levels for ACF almost two-fold better and of the same order of magnitude for CAF when compared with other well-established microextraction techniques. It must also be emphasized that the proposed methodology uses small amounts of sample during the extraction stage and less organic solvent during the back-extraction stage than many other microextraction approaches reported in the literature (e.g., SPE) [14,15,16,17,18].…”

Prospects for using a new sequential chemiluminescence strategy for monitoring the caffeine content in soft and energy drinks via the catalytic activities of different nano‐metal oxides

“…Various analytical methods have been employed to determine the amount of CAF in many matrices, including spectroscopic methods such as spectrophotometry and spectrofluorimetry . Chromatographic separation methods have been addressed for the detection of CAF, including high‐pressure liquid chromatography (HPLC), liquid chromatography tandem mass spectrometry (LC–MS/MS) , thin layer chromatography (TLC), gas chromatography and capillary zone electrophoresis . Furthermore, potentiometry and voltammetry as electrochemical methods have been reported for CAF detection.…”