CLINICALCHEMISTRY, Vol.36, No.3,1993 481 Cocaine and Benzoylecgonine in Saliva, Serum, and Urine

We studied the feasibility of using saliva to detect cocaine and benzoylecgonine. Saliva was collected as an ultrafil-trate directly in the mouth with an osmotic device. We analyzed by immunoassay matched samples of urine, blood, and salivary ultrafiltrate from 69 patients who had used cocaine within 24 h of sample collection. Cocaine concentrations were 4.9 times higher in saliva than in serum; benzoylecgonine concentrations were 2.5 times higher in serum. Seven urine and two serum samples had undetectable concentrations of cocaine, but all 69 saliva samples were positive for the drug. For benzoylecgonine detection, all urine samples were positive and three serum and one saliva sample were n3gative. We also analyzed 43 samples of saliva by gas chromatography/ mass spectrometry: all were positivefor benzoylecgonine