Robert Boll1, Theron Johnson2, Rudolf Kaaks2, Tilman Kühn2, Gisela Skopp3. 1. Institute of Legal and Traffic Medicine, University Hospital Heidelberg, Voss-Str. 2, 69115, Heidelberg, Germany. rb12687@gmail.com. 2. Division of Cancer Epidemiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany. 3. Institute of Legal and Traffic Medicine, University Hospital Heidelberg, Voss-Str. 2, 69115, Heidelberg, Germany.
Abstract
INTRODUCTION: Phosphatidylethanol (PEth), as measured in freshly drawn blood samples, could be a promising new biomarker for habitual alcohol consumption, but it is still unknown whether PEth can also be determined from blood samples having been stored frozen for a longer period. MATERIALS AND METHODS: PEth 16:0/18:1 and PEth 18:1/18:1 were determined by LC-MS/MS from red blood cells (RBC) derived from blood samples of (I) 20 healthy volunteers (after 1 month of storage at -80 °C) and (II) 232 participants of the population-based European Prospective Investigation into Cancer and Nutrition (EPIC)-Heidelberg study (after 20 years of storage at -196 °C). Analyses involved liquid-liquid extraction from 100 μl aliquots with phosphatidylpropanol (PProp 18:1/18:1) as the internal standard. Extracts were subjected to a 10-min LC gradient separation, using multiple reaction monitoring of deprotonated molecules for quantification. RESULTS: After 1 month of storage at -80 °C, PEth was detectable in all samples at mean concentrations of 393.6 ± 12.4 ng/ml (PEth 16:0/18:1) and 43.3 ± 1.1 ng/ml (PEth 18:1/18:1). In samples stored for 20 years at -196 °C, PEth was detectable in 23.7% of all samples at mean concentrations of 412.2 ± 655.5 ng/ml (PEth 16:0/18:1) and 38.0 ± 74.8 ng/ml (PEth 18:1/18:1). DISCUSSION AND CONCLUSION: PEth can be determined reliably from samples of moderate habitual alcohol consumers after 1 month of storage at -80 °C. Our data suggest that PEth is generally also detectable in samples after 20 years of storage at -196 °C. Further studies are needed to assess the still unknown impact of storage duration and temperature on different PEth specimen concentrations.
INTRODUCTION:Phosphatidylethanol (PEth), as measured in freshly drawn blood samples, could be a promising new biomarker for habitual alcohol consumption, but it is still unknown whether PEth can also be determined from blood samples having been stored frozen for a longer period. MATERIALS AND METHODS:PEth 16:0/18:1 and PEth 18:1/18:1 were determined by LC-MS/MS from red blood cells (RBC) derived from blood samples of (I) 20 healthy volunteers (after 1 month of storage at -80 °C) and (II) 232 participants of the population-based European Prospective Investigation into Cancer and Nutrition (EPIC)-Heidelberg study (after 20 years of storage at -196 °C). Analyses involved liquid-liquid extraction from 100 μl aliquots with phosphatidylpropanol (PProp 18:1/18:1) as the internal standard. Extracts were subjected to a 10-min LC gradient separation, using multiple reaction monitoring of deprotonated molecules for quantification. RESULTS: After 1 month of storage at -80 °C, PEth was detectable in all samples at mean concentrations of 393.6 ± 12.4 ng/ml (PEth 16:0/18:1) and 43.3 ± 1.1 ng/ml (PEth 18:1/18:1). In samples stored for 20 years at -196 °C, PEth was detectable in 23.7% of all samples at mean concentrations of 412.2 ± 655.5 ng/ml (PEth 16:0/18:1) and 38.0 ± 74.8 ng/ml (PEth 18:1/18:1). DISCUSSION AND CONCLUSION:PEth can be determined reliably from samples of moderate habitual alcohol consumers after 1 month of storage at -80 °C. Our data suggest that PEth is generally also detectable in samples after 20 years of storage at -196 °C. Further studies are needed to assess the still unknown impact of storage duration and temperature on different PEth specimen concentrations.
Authors: Pamela Cabarcos; José Ángel Cocho; Antonio Moreda; Martha Míguez; María Jesús Tabernero; Purificación Fernández; Ana María Bermejo Journal: Talanta Date: 2013-03-16 Impact factor: 6.057
Authors: H Gnann; C Engelmann; G Skopp; M Winkler; V Auwärter; S Dresen; N Ferreirós; F M Wurst; W Weinmann Journal: Anal Bioanal Chem Date: 2010-02-02 Impact factor: 4.142