Determination of opiates in biological samples by glass capillary gas chromatography with electron-capture detection.

A gas chromatographic method for the simultaneous determination of morphine, 6-acetylmorphine and codeine in human plasma or blood has been developed. The samples are buffered to pH 9 and extracted on silica columns, cleaned by extraction and finally acylated with pentafluoropropionic anhydride. The derivatives formed are separated on a glass capillary column with falling glass needle injection and electron-capture detection. The choice of the extraction conditions and the preparation of suitable capillary columns are discussed.