Validated assay for the quantification of anastrozole in human plasma by capillary gas chromatography-63Ni electron capture detection.

An assay was developed for the quantification of anastrozole [2,2'-[5-(1H-1,2,4-triazol-1-ymethyl)-1,3-phenylene]bis(2-++ +methylpropiononitrile)] in human plasma using liquid-liquid extraction. Anastrozole and an internal standard were chromatographed and detected by gas chromatography with electron capture detection, using a combination temperature-pressure program. The range of the assay is 3 to 100 ng/ml. Anastrozole was quantified by comparing its peak area to that of an internal standard. A cross-validation of this assay was also successfully performed between several laboratories.