Sample amounts of 1 ml solutions that contained 10 pg of drugs (methamphetamine, amphetamine, 3,4-methylene-diosymethamphetamine, cocaine, and heroin) were spotted on silicon wafers for direct analysis. In addition, a leaflet of marijuana was set directly on a silicon wafer; and opium in the form of a soft lump was smeared on another silicon wafer for analysis. The experiments found that 10 pg of contaminant elements could be detected. In a seized methamphetamine sample, iodine was found, which could be indicative of synthetic route. In seized 3,4-methylenedioxymethamphetamine samples, variable amounts of phosphorous, calcium, sulfur, and potassium were found, which could not be detected in a control 3,4-methylenedioxymethamphetamine sample. For marijuana and opium, two spectral patterns were obtained; they were very different from one another and could be easily distinguished. Thus, using SR-TXRF permits the detection of pg amounts of each trace element in 10 mg of various drugs. This is not the case for either a standard TXRF experimental system or for other elemental analysis techniques. 7 illustrative figures and 33 references