Metabolite Sensitivity in the Methaqualone Radioimmunoassay

Abstract

The use of radioimmunoassay (RIA) as a method capable of detecting nanogram-per-millilitre (ng/ml) quantities of methaqualone in biological specimens has been described previously [1,2]. Several authors have shown, by using gas chromatography or mass spectrometry, or both, that the principal products of methaqualone metabolism, as they appear in the urine, are primarily the monohydroxy derivatives [3–5]. These derivatives have been found to be conjugated mainly with glucuronic acid. In this study the relative sensitivity of methaqualone and its metabolites to the RIA assay was investigated.