Dennis M. Chinn

Simultaneous Determination of Cocaine and Benzoyl Ecgonine in Urine by Gas Chromatography with On-Column Alkylation

A gas chromatographic procedure has been developed for the simultaneous determination of cocaine and benzoyl ecgonine in urine specimens. The two drugs are extracted by isopropanol/chloroform from urine samples saturated with a bisalt buffer. The organic extract is evaporated to dryness, and an aliquot of the residue is injected onto the gas chromatograph to determine the presence of cocaine and the location of any extraneous peaks. Benzoyl ecgonine is then analyzed as its particular alkyl ester subject to the least interference from extraneous peaks as observed in an initial underivatized injection. The reconstituted residue is co-injected with the appropriate dimethylformamide dialkyl acetal for on-column alkylation. The use of two columns or more than one benzoyl ecgonine alkyl ester gives positive identification, and the use of isopropyl benzoyl ecgonine as an internal standard allows accurate quantification.

Drugs and driving: a systematic analytical approach

To collect useful epidemiological data about drug involvement in highway safety, it is essential that sensitive and specific analytical procedures be used to establish the presence of and to determine the concentrations of drugs and metabolites in samples collected from drivers. This paper describes a comprehensive and systematic screening procedure requiring 6 mL of blood, which has been used for the analysis of samples collected from injured and fatally injured drivers. The procedure uses radioimmunoassay, gas chromatography with selective detectors, and high performance liquid chromatography. Drugs and metabolites presumptively identified are then confirmed primarily using gas chromatography--chemical ionization mass spectrometry.

A Survey of Drug Use among Probationurs in the Los Angeles Area in 1976

The results are presented from the analysis of 10,000 urine specimens from Los Angeles County probationers in early 1976 for the following drugs: amphetamine, methamphetamine, allylbarbital, amobarbital, butabarbital, pentobarbital, phenobarbital, secobarbital, morphine, codeine, methadone, primary metabolite of methadone, cocaine, benzoylecgonine, propoxyphene, norpropoxyphene, methaqualone, and phencyclidine. Over 27% of the urine samples analyzed were positive for at least one drug. Opiates were found to be the most widely used drugs, but multiple drug use was also quite common.