Development and validation of a simple and rapid thin-layer chromatography–UV densitometry method for the determination of triazophos in human whole blood for forensic toxicological applications

Abstract

No published studies reported triazophos (TZP) analysis in human whole blood following fatal intoxication. In this study, a method for the determination of TZP in human whole blood using liquid–liquid extraction (LLE) and thin-layer chromatography (TLC)–ultraviolet (UV) densitometry is described. Chromatography was performed on silica gel 60F254 TLC plates using mobile phase n-hexane:acetone (8:2, v/v) and UV densitometric detection at 248 nm. Better extractions were achieved by using ethyl acetate solvent at pH 5 with a recovery of 92.17%. Calibration curve for TZP in blood was linear from 2 to 100 μg/mL (0.04 to 2 μg/spot) and the sensitivity of the method (LLOQ) was 2 μg/mL (0.04 μg/spot). The method showed excellent within-day precision (0.37 to 0.82%, RSD) and between-day precision (0.39 to 1.47%, RSD) for spiked blood samples at 2, 10, and 50 μg/mL. The measured concentrations of TZP in blood did not deviate more than 2.69% under different storage conditions. TZP concentrations in two fatal cases of poisoning were reported. To the best of our knowledge, this is the first validated TLC–UV densitometric method developed to determine TZP in human whole blood.