Gas chromatography with surface ionization detection: a highly sensitive method for determining underivatized codeine and dihydrocodeine in body fluids

• Published in: Journal of chromatography. B, Biomedical applications Biomedical applications, 1995-11, Vol.673 (2), p.189-195
• Main Authors: Seno, H., Hattori, H., Kurono, S., Yamada, T., Kumazawa, T., Ishii, A., Suzuki, O.
• Format: Article
• Language: English
• Subjects: Adult; Chromatography, Gas - methods; Codeine - analogs & derivatives; Codeine - blood; Codeine - urine; Humans; Male; Microchemistry; Sensitivity and Specificity
• ISSN: 0378-4347; 1572-6495
• DOI: 10.1016/0378-4347(95)00275-1

Underivatized codeine and dihydrocodeine in human plasma and urine have been determined with a high degree of accuracy by capillary gas chromatography (GC) with surface ionization detection (SID). The drugs were extracted with the aid of Sep-Pak C 18 cartridges. Recovery of both drugs was ⩾ 90%. The calibration curves obtained with dimemorfan as an internal standard showed linearity in the range 4.5–72.3 and 3.0–75.5 ng/ml of plasma for codeine and dihydrocodeine, respectively. The detection limit was about 100 pg on column (2.5 ng/ml sample). Codeine was determined quantitatively in plasma and urine obtained from a volunteer who had received 10 mg codeine phosphate orally 3 h before the sampling: the levels were found to be 14.1 and 142 ng/ml, respectively. The present GC-SID method has been compared carefully with GC-NPD (nitrogen-phosphorus detection) using the same extracts; the sensitivity of GC-SID was more than ten times greater than that of GC-NPD, with background noise correspondingly lower.