Gas chromatography with surface ionization detection: a highly sensitive method for determining underivatized codeine and dihydrocodeine in body fluids.
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 C18 cartridges. Recovery of both drugs was > or = 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.
Seno
H
H
Department of Legal Medicine, Hamamatsu University School of Medicine, Japan.
Hattori
H
H
Kurono
S
S
Yamada
T
T
Kumazawa
T
T
Ishii
A
A
Suzuki
O
O
D000328:Adult; D002849:Chromatography, Gas / Q000379:methods*; D003061:Codeine / Q000031:analogs & derivatives* / Q000097:blood* / Q000652:urine*; D006801:Humans; D008297:Male; D008832:Microchemistry; D012680:Sensitivity and Specificity
C014481:dihydrocodeine; D003061:Codeine