KHẢO SÁT GIỚI HẠN ĐỊNH LƯỢNG VÀ KHOẢNG ĐO MỚI CHO PHƯƠNG PHÁP ĐỊNH LƯỢNG ETHANOL TRONG MÁU BẰNG PHƯƠNG PHÁP SẮC KÝ KHÍ ĐẦU DÒ FID KẾT HỢP KỸ THUẬT KHÔNG GIAN HƠI (GC-HS-FID)

Abstract

Objective: To validate a procedure for the quantification of ethanol in blood using headspace gas chromatography with flame ionization detection (GC-HS-FID), aiming to establish a new calibration range with a lower limit of quantification (LoQ), in compliance with legal requirements in the field of traffic safety. Methods: Analysis was performed on an Agilent 7890A. The procedure was validated according to USFDA guidelines, including the following parameters: specificity, lower limit of quantification (LLOQ), linearity, accuracy, precision, extraction recovery, and carryover effect. Results: The method met all validation criteria: LLOQ was established at 0.0015%, with a signal-to-noise ratio (S/N) ≥ 5, accuracy of 91,11%, and a coefficient of variation (CV) of 13,62%. Linearity was established within the range of 0.0015% - 0,6% (R² = 0.9986). Intra- and inter-day accuracy and precision met the acceptance criteria, with CV% ≤ 15%, and at the LLOQ ≤ 20%. Recovery was ≥ 80%, with CV% ≤ 10%. Carryover was not observed beyond acceptable thresholds. The method was applied to 15 patient samples, yielding accurate ethanol quantification results. Conclusion: The new calibration range with a low quantification limit (1,5 mg/dL) suitable for practical applications in determining blood ethanol concentration.