[Personal experience with quantitative high performance thin layer chromatography]

In 5 substances from the group of non-barbiturate hypnotics (methaqualone, nitrazepam) and psychopharmaceutical preparations (thioridazine, dosulepin, imipramine) the author selected for quantitative high performance thin-layer chromatography a method of direct densitometry, i.e. assessment of absorption in visible light after colour detection by the transmission technique. The assembled results are evaluated by statistical methods. By suitable adjustment of the chromatographic separation and of the parameters of measurement during densitometry in each investigated substance a correlation coefficient r better than 0.997 and a variation coefficient V lower than 10% can be obtained.