title: Impact of the grinding process on the quantification of ethyl glucuronide in hair using a validated UPLC-ESI-MS-MS method.
abstract: The Society of Hair Testing (SoHT) has provided cutoffs for the quantification of ethyl glucuronide (EtG) in hair to indicate occasional or chronic/excessive alcohol consumption. Although several sensitive methods have been reported, past proficiency test results show a lack of reproducibility. An ultra-performance liquid chromatographic mass spectrometric method (LLOQ of 10 pg EtG/mg hair) has been validated according to the international guidelines, including the successful participation in five proficiency tests. This method was subsequently used to evaluate the impact of different grinding conditions (cut, weakly or extensively pulverized hair samples) on the final measured EtG concentration. Hair from alcohol consumers (n = 2) and commercially available quality control samples (QCs) (n = 2) was used. For the QCs, extensive pulverization led to a significantly higher amount of measured EtG. In the hair samples obtained from volunteers, cut or weakly pulverized hair resulted in EtG concentrations below the LLOQ, while the mean concentrations of 14 and 40 pg EtG/mg hair were determined after extensive pulverization. Differences in sample preparation could partially explain inter-laboratory variability. As the differences in results can lead to a different interpretation even when applying the SoHT cutoffs, it is of interest to standardize sample preparation techniques in the field of EtG hair testing.
authors.affiliation: Federal Public Service Justice, National Institute of Criminalistics and Criminology, Brussels, Belgium natalie.kummer@just.fgov.be.
authors.forename: Natalie
authors.initials: N
authors.lastname: Kummer
authors.affiliation: Federal Public Service Justice, National Institute of Criminalistics and Criminology, Brussels, Belgium.
authors.forename: Sarah M R
authors.initials: SM
authors.lastname: Wille
authors.affiliation: Federal Public Service Justice, National Institute of Criminalistics and Criminology, Brussels, Belgium.
authors.forename: Vincent
authors.initials: V
authors.lastname: Di Fazio
authors.affiliation: Federal Public Service Justice, National Institute of Criminalistics and Criminology, Brussels, Belgium.
authors.forename: Maria Del Mar
authors.initials: Mdel M
authors.lastname: Ramírez Fernández
authors.affiliation: Laboratoire National de Santé, Service de Toxicologie, Dudelange, Luxembourg.
authors.forename: Michel
authors.initials: M
authors.lastname: Yegles
authors.affiliation: Laboratory of Toxicology, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium.
authors.forename: Willy E E
authors.initials: WE
authors.lastname: Lambert
authors.affiliation: Federal Public Service Justice, National Institute of Criminalistics and Criminology, Brussels, Belgium.
authors.forename: Nele
authors.initials: N
authors.lastname: Samyn
mesh_terms: D000428:Alcohol Drinking; D000437:Alcoholism / Q000175:diagnosis; D002853:Chromatography, Liquid; D005260:Female; D005965:Glucuronates / Q000032:analysis*; D006197:Hair / Q000737:chemistry*; D006801:Humans; D008297:Male; D011786:Quality Control; D012015:Reference Standards; D015203:Reproducibility of Results; D013048:Specimen Handling; D053719:Tandem Mass Spectrometry
chemical_list: D005965:Glucuronates; C093924:ethyl glucuronide