Calibration thin layer chromatography

Ebel, S. Evaluation and Calibration in Quantitative Thin-Layer Chromatography, 126, 71-94... 

Ebel, S. Evaluation and Calibration in Quantitative Thin-Layer Chromatography. 126,71-94 (1984). Ebert, T. Solvation and Ordered Structure in Colloidal Systems. 128, 1-36 (1985). 

Chromatographic Parameter-Relationships Correlations between Kov/ and various chromatographic parameters (CGP), such as HPLC retention time and thin-layer chromatography (TLC) capacity factors, allow the experimental estimation of Kow [19]. Usually, the CGP-A ow correlation is evaluated for a calibration set of compounds with accurately known K0w values. The Kow of a new compound can then be estimated by determining its CGP under the same experimental conditions as those used for the calibration set. 

Semenov et al. [8] determined small amounts of petroleum products in chloroform extracts of non saline water by extracting the sample (200-500mL) followed by thin layer chromatography on alumina. He developed the chromatogram with light petroleum-carbon tetrachloride-acetic acid (35 155 1), and examined the plate in ultraviolet radiation the petroleum products exhibit three zones (pale blue, yellow and brown). Each zone is then extracted with chloroform, the fluorescence of the extracts measured and the results referred to a calibration graph. The sensitivity is O.lmg L. The infrared and fluorescence spectra of the zone obtained with various petroleum products are discussed. 

It was used Sparteine, from Sigma, as an internal standard, and the final concentration of Sparteine in the samples was 0.102 g/1. The lupanine used to make the calibration curves of the chromatograph was extracted from the lupine flour using methanol and separated by using the thin-layer chromatography, according the method described by Cho and Martin (1971). 

Evaluation and Calibration in Quantitative Thin-Layer Chromatography... 

As in thin-layer chromatography the calibration curves are usually only linear in a limited range, various linearisation functions are provided in the software program of this system, but also non-linear calibration curves for working in a wider concentration range 15). 

Compared to other kinds of chromatography the measuring time in thin-layer chromatography is very short, as the substances do not have to be eluted. Multiple measurements of calibrations on each plate, however, are necessary this reduces the advantage slightly. 

Another application to pre- and newborns was published by Liu et al. in 1997 [95]. In this paper, they presented a measure of fetal lung maturity from the spectra of amniotic fluid. The lecithin/spingomyrlin (L/S) ratio was determined by thin layer chromatography (TLC) and used to calibrate a NIR equation using the whole amniotic fluid extracted from pregnant women. About 350 iL of fluid was required. This was scanned from 400 to 2500 nm using a commercially available instrument. The correlation between further samples of fluid and TLC results was about 0.91, considered excellent for the complexity of the solution and extremely small sample size. Of course, a PLS equation was needed due to the complex nature of the samples. 

Other chemical calibrations depend on, for example, chromatographic peak area, emission intensity, current, voltage, position on a thin layer chromatography or electrophoresis plate (expressing voltage gradients). 

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