A specific G. C. method for the determination of carbamazepine in blood

Carbamazepine is extracted with dichloromethane from whole blood. After a rinsing procedure the residue is gaschromatographed partly in methanol, where two peaks occur, and partly in a methylating reagent, where the same two peaks are seen, the heights of these now being reversed. This reversal is used as a means of identification. Recovery was found to be 94 +/- 12 %. Blood analysis from 12 patients being treated with carbamazepine gave values from 0.6 - 6.5 mg/kg.