Rapid and sensitive determination of morphine in street opium samples by thermal desorption gas chromatography using a microfurnace pyrolyzer

Thermal desorption of the alkaloids in opium samples at 300°C using a vertical microfurnace pyrolyzer was followed by their on‐line gas chromatographic (GC) analysis on a large‐bore glass capillary column. This method permitted rapid and sensitive determination of the content of the main alkaloid, morphine, in the small (ca. 100 μg) opium samples with a relative standard deviation within 4% for 5 runs. The observed morphine contents of about 12 to 15 w/w % in the given opium samples were in fairly good agreement with those estimated by a conventional GC‐MS method.