Simultaneous determination of hydromorphone, hydrocodone and their 6alpha- and 6beta-hydroxy metabolites in urine using selected ion recording with methane chemical ionization.

A selected ion recording using chemical ionization (methane) is described for the simultaneous measurement of hydrocodone, hydromorphone and their respective 6alpha- and 6beta-hydroxymetabolites in human urine. The samples were acid-hydrolyzed, extracted and derivatized by silylation. Only partial resolution of the components on 3% OV-17 was achieved but was sufficient for their determination. The [M+1]+ ions of the drugs and metabolites as well as the [M+29]+ ion of the internal standard were recorded. The assay was sensitive down to c. 0.01 microgram ml-1. The relative standard deviation of standards processed along with the samples ranged from 4.5-8.2%. Hydrocodone was found to be metabolized in man primarily by O-demethylation and 6-keto reduction. Hydromorphone was excreted mainly in the unchanged form (after acid-hydrolysis) with only minor amounts of the 6-hydroxymetabolites being detected. A lack of stereoselectivity in the metabolic reduction ofhydrocodone was observed.