Institute of Forensic Research, Westerplatte 9, 31-033 Cracow, Poland

For underivatized drugs four independent mobile phases and a sequence of different spray reagents were used. Visualization of chromatograms can lead to coloured spots (with Fast Blue B salt, Fast Blue RR salt, ninhydrin, Marquis reagent) or to fluorescent derivatives (with 2-amino-methyl-1,3-propandiol buffer and potassium hexacyanoferrate (III), and fluorescamine).

The screening of dansylated cannabinoids, phenylethylamines, morphine and heroin was based on four other mobile phases used in succession. In the first phase cannabinoids (R_F 5-8) were developed, in the second cannabinoids (R_f19-30) and amphetamines (R_f 6-21), in the third amphetamines (R_f 20-62), and in the fourth morphine and heroin (R_f 28 and 53 respectively). This method generally enabled the differentiation of cannabinoids, amphetamines and opiates from other drugs, biological and non-biological matrices, and in most cases from each other. Fluorescent dansyl derivatives of compounds studied were often sensitive enough to be detected in hundred nanogram quantities or less by the TLC screening method described.

Screening by examination of dansylated drugs, followed by confirmation using appropriate chromatographic systems for underivatized drugs, identifies the drugs.