Optimization and validation of a gas chromatography method for the determination of ethanol in blood samples

Abstract: Ethanol is a psychoactive substance. Its abuse has health, regulatory and medico-legal consequences. Consequently, the determination of blood alcohol concentration (BAC) necessitates a highly sensitive and robust analytical procedure. To address this necessity, the National Agency for Health, Environmental, Food, Labor, and Health Product Safety (ANSSEAT) has developed a validated method for BAC quantification. Blood samples were collected in tubes containing fluoride from 14 volunteers who did not drink alcohol and were then spiked with ethanol. Sample preparation involved treatment with trichloroacetic acid, incorporating n-propanol as an internal standard. Validation parameters were established in accordance with the protocol described by Feinberg et al. (1996). Analytical measurements were conducted using gas chromatography equipped with a flame ionization detector (GC-FID), headspace injector and nitrogen gas. Data acquisition and processing were executed using ChemStation software and Microsoft® Excel 2016. The response function adhered to a linear regression model (y = 1498.2x - 0.5957, r² = 0.9999). Results demonstrated linearity, precision, accuracy, selectivity, and robustness across the concentration range of 0.1 to 1 g/L. The validated limit of quantification was determined to be 0.03 g/L ± 0.0008, with a matrix effect correction factor of 0.89%. The BAC determination method validated by ANSSEAT enhances the institution's analytical capabilities, thereby reinforcing its contribution to public health initiatives. Keywords: Validation, Blood Alcohol Concentration (BAC), GC-FID