Opiate Detection in Saliva and Urine—A Prospective Comparison by Gas Chromatography–Mass Spectrometry

Abstract

There is an increasing interest in saliva as an alternative analytic body fluid. Objective: This study sought to determine the correlation of opiates analyzed in saliva and corresponding urine. Methods: A total of 130 adequate and 24 inadequate samples were collected from patients participating in drug withdrawal therapy. To obtain saliva from the oral cavity, a newly developed collection device (Clin Rep^®), consisting of a treated cotton roll and a centrifugation vial with a filter inset, was tested. For the preparation of a purified solution of urine, liquid extraction was used. Solid phase extraction was utilized to prepare the saliva samples. For the detection by gas chromatography–mass spectrometry, an appropriate derivatization was necessary using N-methyl-N-(trimethyl-silyl)trifluoroacetamide. The retention times were compared with defined standard solutions. The obtained mass spectra showed a characteristic fragmenting pattern and offered a reliable identification. Results: The concordance of the analytic results of the saliva samples with urine was 93percnt; for a decision limit of 100 ng/mL and 98% for a decision limit of 300 ng/mL (DHHS opiate cutoff) in urine. Conclusions: Saliva, of adequate amount in 85% of samples, may be appropriate for analysis of drugs of abuse.