Investigations on the influence of different grinding procedures on measured ethyl glucuronide concentrations in hair determined with an optimized and validated LC-MS/MS method.

Ethyl glucuronide (EtG) analysis in hair is a suitable method for the retrospective determination of previous alcohol consumption. According to the German guidelines, EtG abstinence is improbable at c(EtG) > 7 pg/mg in the proximal 3 cm of scalp hair. The chromatography of the routinely used liquid chromatography-tandem mass spectrometry procedure was optimized by replacing the stationary phase. To simplify sample preparation, two different mills were tested, and an optimized grinding process was developed. The new method was successfully validated according to the guidelines of the German Society of Toxicological and Forensic Chemistry. Despite a simple extraction procedure without any cleaning steps, a very high sensitivity (limit of detection, 1.7 pg/mg; limit of quantitation, 2.3 pg/mg) could be achieved. Competitive analysis showed significantly higher EtG concentrations in pulverized versus cut hair samples. The strong impact of sample preparation on the determined EtG concentrations suggests the introduction of a standardized sample preparation method to produce comparable results.

A high-performance liquid chromatographic-tandem mass spectrometric method for the determination of ethyl glucuronide and ethyl sulfate in urine validated according to forensic guidelines.

Ethyl glucuronide (EtG) and ethyl sulfate (EtS) are powerful markers for alcohol intake and abuse. Several analytical procedures for the quantification of EtG and EtG in serum and urine have been developed so far. Many of the published methods show limits of detections (LODs) or limits of quantifications (LOQs) for EtG in urine within the range of 0.1 mg/L or higher. Since this is the actual cutoff value for proving abstinence in Germany, problems may occur if urine samples are highly diluted. In this paper, the validation of a highly sensitive, fast and simple LC-MS-MS for the determination of EtG and EtS in urine is described. The calibration curves for EtG and EtS is linear over the whole range (0.025-2.0 mg/L). Very low detection limits can be achieved (LOD: EtG 0.005 mg/L, EtS 0.005 mg/L; and LOQ: EtG 0.019 mg/L, EtS 0.015 mg/L). All data for selectivity, precision and accuracy, recovery, as well as for the processed sample and the freeze/thaw stability, comply with the guidelines of the German Society of Toxicological and Forensic Chemistry. Strong matrix-related effects can be compensated for by using an internal standard. Finally, the applicability of the procedure is proven by analysis of 87 human urine samples and by successful participation in interlaboratory comparison tests.

Comparison of ethyl glucuronide (EtG) and fatty acid ethyl esters (FAEEs) concentrations in hair for testing abstinence.

Hair analysis is a powerful tool for retrospective drug analysis. By determining the minor ethanol metabolites ethyl glucuronide (EtG) and fatty acid ethyl esters (FAEEs) in hair, even a previous consumption of alcohol is detectable. However, previous studies showed a lack of correlation if both parameters are determined simultaneously. A further study was conducted to confirm or refute these results. One hundred and sixty hair samples were analyzed for EtG and FAEE in the context of driving ability. In 109 cases, alcohol abstinence was clearly proven and was excluded in 15 cases. In 36 cases, ambiguous results were found. Possible reasons for the deviating results are discussed. It is recommended, that in context of driving ability diagnostics the EtG result is determinant. In critical cases FAEE concentrations can be determined for checking purposes, but a negative FAEE result cannot refute a determined EtG concentration >7 pg/mg.

Determination of glycyrrhetic acid after consumption of liquorice and application to a fatality.

Besides alcohol and drugs of abuse, several popular foods contain potentially toxic substances and cases of intoxication after consumption of these foods attract notice of forensic toxicology. This is also true for the case of a 34-year-old woman who was suspected to have suffered lethal acute intoxication from eating nothing but liquorice over a period of several months. The liquorice ingredient glycyrrhizin and its metabolite glycyrrhetic acid, which elicits a mineralocorticoid effect, were determined in the sort of liquorice the woman had consumed by using LC-MS/MS. In addition, a fast and sensitive procedure for the quantification of glycyrrhetic acid including a simple sample preparation was developed. The method was proven to be accurate and precise. In a liquorice ingestion experiment, 200 g of liquorice had to be eaten. Afterwards, concentrations of glycyrrhetic acid in the blood of up to 434 ng/ml were measured. Since only traces of glycyrrhetic acid had been found in the blood and stomach content of the deceased woman, the possibility of acute lethal glycyrrhetic acid intoxication could be eliminated. Excluding other causes of death, the woman is believed to have died from a lethal hyperglycemic coma. Nonetheless, the influence of harmful and toxic substances in food should be taken into consideration in special cases.