市販酵素免疫キットを用いる尿中乱用薬物の分析  [in Japanese] Analysis of Abused Drugs in Human Urine with Commercial Enzyme Immunoassay Reagents  [in Japanese]

A simple, rapid and sensitive screening method and semiquantitative analysis for abused drugs, methamphetamine (MA), morphine (MO), cocaine (COC) and cannabinoid (CN), in the urine sample were investigated usine the Syva Emit st^<TM> urine assay reagent with Shimadzu CL-770,the temperature-controlled spectrophotometer. A sample was diluted and mixed in an Emit st^<TM> urine reagent vial with an Emit st^<TM> dilutor. Thirty seconds after mixing, the mixture was transferred to the flow cell of the spectrophotometer kept at 37℃, and the absorbance change at 349 nm was measured for 30 s (60 s for CN). Calibration curves were examined over a range of 0 to 50 μg/ml for MA, morphine-3-glucuronide (M3G) and benzoylecgonine (BE), 0 to 0.5 μg/ml for Δ^9-tetrahydrocannabinol-11-oic acid (THC-COOH), and were found to be relatively linear between 0 and 0.5 μg/ml for MA and M3G, 0 and 1 μg/ml for BE, 0 and 0.3 μg/ml for THC-COOH. Cutoff values were able to be set at the concentration of 0.5 μg/ml for MA, 0.5 μg/ml for M3G (corresponding to 0.2 μg/ml), 0.3 μg/ml for BE, 0.1 μg/ml for THC-COOH, and within-run coefficients of variation (C. V.) for the samples of the cutoff levels were less than 2% (n=10). The quantitative results from enzyme multiplied immunoassay technique (EMIT) assays for 100 urine samples were compared with those from GC, GC/MS and LC/MS, and the former showed an excellent correlation with the latter for MA and BE levels. Dihydrocodeine, however, showed a high cross-reactivity with MO, which often caused "false positive results."