Detection: 

In situ quantitative analysis is carried out by direct photometric measurements. By this reason, single or double beam spectrophotometers are available. Scanning densitometers based on reflectance and absorbance of light is often used to measure the individual spots. The chromatogram is scanned with a moving beam of light and the intensity of reflected light from the plate surface is measured. The difference in light intensity among the thin layer plate without sample and along with spot is displayed as peaks in the scan. The areas of peaks correspond to the amount of solute component in the sample. An alternate procedure consists in measuring the light transmitted through the plate. Photodensitometers measure the transmitted or reflected light to produce a photograph revealing dark and light zones for the areas of constituents in the sample. A standard deviation for quantitative determinations through densitometry is better than 5%.

CAMAG, Switzerland have developed a HPTLC Vario system with key features of development with six different solvents side by side, sandwich as well as tank configuration making directly comparable results, and six different conditions of equilibration including relative humidity.