Optimized alcohol detection in postmortem vitreous humor using magnetic needle headspace single-drop microextraction and box-behnken design.

An innovative method for measuring alcohol levels in postmortem samples, particularly focusing on vitreous humor, was developed. The research examined the impact of a constant magnetic field on selective solvents in the single-drop microextraction technique (SDME), utilizing gas chromatography with flame ionization detector (GC-FID). The results indicated that using ethylene glycol (EtG) as solvent, the application of a magnetic field increased the efficiency of methanol and ethanol extractions from vitreous samples by up to 23.2 and 18.5 %, respectively. This method significantly improved extraction efficiency, linear range, detection limit, and accuracy compared to other techniques, making it a valuable approach for alcohol measurement in forensic medicine. The parameters were optimized using a Box-Behnken design of experiments. The optimal conditions included a temperature of 70 °C, an extraction time of 12 min, a drop volume of 2 µL, and a salt mass of 0.06 g. The method demonstrated a linear range of 10-1500 mg/L with limits of detection (LODs) ranging from 1.30-1.90 mg/L. Additionally, an R² value of 0.999 and a relative extraction efficiency of 93.4-106.6 % were achieved. By incorporating the innovative use of a magnetic field and the SDME method, this research significantly enhanced the accuracy and sensitivity of postmortem alcohol measurements, thereby advancing diagnostic techniques in forensic toxicology.