ACIDIC AND NEUTRAL-DRUGS SCREEN IN BLOOD WITH QUANTITATION USING MICROBORE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY DIODE-ARRAY DETECTION ANDCAPILLARY GAS-CHROMATOGRAPHY FLAME IONIZATION DETECTION

Blood previously acidified with aqueous saturated ammonium chloride so lution was extracted with ethyl acetate. The dried extract was subject ed to acetonitrile-hexane partition. The acetonitrile portion was anal ysed for the presence of acidic and neutral drugs by HPLC-DAD (200 mmX 2.1 mm I.D. microbore ODS-Hypersil column) and GC-FID (25 m narrow-bor eX0.25 mm I.D. HP-5 column with 0.33 mu m film thickness). The protoco l was found to be suitable for both clinical toxicology (including eme rgency toxicology) and postmortem toxicology. At least 66 drugs of int erest were unequivocally identified by RRTs (HPLC) and UV spectra (DAD ) match while another 12 were unequivocally identified by double RRTs match (HPLC and GC). Quantitation was facilitated by incorporating cal ibration blood standards in each assay batch. The five drugs most comm only encountered in clinical blood specimens (1150 cases) were: parace tamol (47.4% of the cases); chlormezanone (6.6%), theophylline (1.74%) , naproxen (1.65%) and mefenamic acid (1.56%). The following drugs wer e detected in toxicologically significant quantities in postmortem blo od specimens (245 cases): phenobarbitone (1.22% of the cases), naproxe n (0.82%), chlormezanone (0.82%), theophylline (0.82%), carbamazepine (0.41%) and paracetamol (0.41%). (C) 1997 Elsevier Science Ireland Ltd .