QUALITATIVE AND QUANTITATIVE-DETERMINATION OF ILLICIT HEROIN STREET SAMPLES BY REVERSED-PHASE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY - METHOD DEVELOPMENT BY CARTACO-S

The development of a method involving reversed-phase HPLC using CARTAGO-S, a spreadsheet computer program as a method development tool is described for the simultaneous qualitative and quantitative determination of heroin in illicitly manufactured street samples containing by-products originating from opium and also commonly occurring adulterants that have been found in Switzerland. The method utilizes simple sample dissolution followed by reversed-phase HPLC on a 3-mu m ODS-1 column with acetonitrile-water-phosphoric acid-hexylamine as the mobile phase. UV detection and quantification were carried out at 210 nm. The optimum linear gradient elution consisted of four steps with a total duration of 36 min. Excellent agreement between predicted and measured retention times with differences ranging from 0.45% to 6.8% was found. For calibration, all compounds showed a good linear relationship between peak area and concentration. The low UV cut-off of this mobile phase allows the detection of heroin and related compounds at its major UV absorption at 210 nm. With this method, the limits of detection absolute ranged from 10 ng for noscapine, corresponding to 0.09% of the sample mass, in the best case to 100 ng for cocaine in the worst case, depending on molar absorptivities.