Chromatography Forum

Hello!

Does anyone know if it is possible to compute for the concentration of each spot in TLC assuming I did 15 spots of 10,000 ppm sample? However, I haven't measured the diameter of the spot and the capillary tube used if they're necessary for the calculation.

I haven't done anything like this for years, but used to do it for carbon-14-labelled sugars with a phosphoimager as detector. I used a calibration curve from spots with known amounts of 14C. Whatever you're doing, you'd have to build an appropriate calibration curve, and check the linearity and reproducibility of your quantification (the bands are going to vary in size, so you need to know whether the intensity of the band is saturating in the middle, which will make it hard to quantify if some are more spread out than others). But yes, with lots of provisos, quantitative tlc is possible, with the right method of detection.

Sounds like a pain, could you develop a UV assay for it, cut the spots out disove in an appropriate solvent, filter out the silica, dry, reconstitute and run on UV against the curve. Not too familiar with quantitation for a TLC, but I have used 2D TLC to purify and recover products, just don't know how efficient the recovery was, for quantitation it needs to be near 100%.

Search for papers on

"tlc quantitative analysis imagej" or image processing


and have a look here:
http://shinyapps.ernaehrung.uni-giessen.de/quanTLC/

Depending in your needs and accuracy limits, HPTLC can still be powerful tool if done right.
If course, the sample prep and applicatiin has to be as accurate as in "normal" quantitative analyses