DEVELOPMENT AND VALIDATION OF A GC-NPD/micro-ECD METHOD USING DUAL COLUMN FOR THE DETERMINATION OF BENZODIAZEPINE IN HUMAN WHOLE BLOOD AND PLASMA

Four benzodiazepines flunitrazepam, nitrazepam, clonazepam, and alprazolam, have been analyzed from biological matrices by dual column gas chromatography using a nitrogen-phosphorus detector (NPD) and a micro-electron capture detector (m-ECD). The recoveries of the four benzodiazepines spiked into human whole blood and plasma were 88.8 - 97.9 and 90.7 - 97.5%, respectively. The regression equations for the four benzodiazepines showed excellent linearity. The detection limits (LODs) were 0.14 - 0.95 ng/mL for whole blood and 0.13 - 0.93 ng/mL for plasma. The method is simple and sensitive for the determination of benzodiazepines in human whole blood and plasma, and may be useful in forensic science practice.