Sensitive determination of four general anaesthetics in human whole blood by capillary gas chromatography with cryogenic oven trapping

Four general anaesthetics, sevoflurane, isoflurane, enflurane and halothane , in human whole blood, have been found measurable with very high sensitivi ty by capillary gas chromatography-flame ionization detection (GC-FID) with cryogenic oven trapping upon injection of headspace (HS) vapor sample. To a 7-ml vial, containing 0.48 nil of distilled water and 20 mul of internal standard solution (5 mug), a 0.5-ml of whole blood sample spiked with or wi thout anaesthetics, was added, and the mixture was heated at 55 degreesC fo r 15 min. A measure of 10 nil HS vapor was injected into the GC in the spli tless mc de at -40 degreesC oven temperature, which was programmed up to 25 0 degreesC. All four peaks were clearly separated; no impurity peaks were f ound among their peaks, Their extraction efficiencies were about 10%. The c alibration curves showed good linearity in the range of 0.5-20 mug/ml their detection limits were 10-100 ng/ml, which are almost comparable to those b y previous reports. The coefficients of intra-day and day-to-day variations were 6.5-9.8 and 7.3-17.2%, respectively. Isoflurane or enflurane was also measured from whole blood samples in which three volunteers inhaled each c ompound. (C) 2001 Elsevier Science B.V. All rights reserved.