Reproducibility of densitometric and image analysing quantitative evaluation of thin-layer chromatograms

This paper presents a comparison of quantification of thin-layer chromatographic plates with slit-scanning densitometry and with two image-analysing systems. Camag test dye mixture UI was used as a sample. The influence of different measuring beam dimensions (slit width and slit length) on the quantitative evaluation of thin-layer chromatograms was studied in the reflectance as well as in the transmission mode. The slit length has a much higher influence on the reproducibility of the measured areas than the slit width. The results obtained with both CCD cameras show linear correlation between response area and concentration of Camag test dye mixture III in a higher concentration range than the densitometrically obtained results. The sensitivity of the used image-analysing systems was much lower than that of the slit-scanning densitometer. (C) 1997 Elsevier Science B.V.