Analysis of therapeutic and commonly abused drugs in serum and urine by gas-liquid chromatography using a photoionization detector.

A simple, rapid and sensitive gas chromatographic procedure using the photoionization detector (PID) was developed for the detection and quantitation of several drugs in serum and urine. In order to evaluate the performance of the PID, the results were compared with those of the flame-ionization detector (FID). The data indicate that the PID is 8-16 times more sensitive than the FID for the drugs studied in the barbiturate group. Excellent reproducibility was found for samples quantitated with the PID on a routine basis. The PID and FID produced statistically similar results on extracted serum samples. The correlation coefficient was 0.99. The PID also produced chromatograms with less background than those obtained with the FID for many extracted serum samples. The advantages of the PID for drug analysis in biological fluids include simplicity of operation, lack of solvent response, universal drug response, non-destructive character and stability.