Comparison of a DS-horizontal chamber and a new Smin chamber in TLC separation

The chromatographic characteristics of a popular DS-horizontal chamber (Chromdes, Poland) and an S_min chamber with a minimum gas volume (Institute of Petrochemical Synthesis of the Russian Academy of Sciences) have been experimentally evaluated.     

The use of thin-layer chromatography in the analysis of lubricating oils

Summary A report is given on the application of thin-layer chromatography to the analysis of additives in lubricating oils. The separation and identification of antioxidants, phenates, sulphonates, zinc dialkyl dithiophosphates and polymeric additives is described. A measurement of additive depletion in used oils is possible by comparison of corresponding chromatograms.

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Zusammenfassung Es wird über die Verwendung der Dünnschicht-Chromatographie bei der Analyse der Additive von Schmierölen berichtet. Die Abtrennung und Identifizierung von Antioxydantien, Phenolaten, Sulfonaten, Zinkdialkyldithiophosphaten und polymeren Additiven wird beschrieben. Eine Messung der Abnahme der Additivkonzentration in gebrauchten Ölen ist durch Vergleich entsprechender Chromatogramme möglich.

     

The thin-layer chromatography of dinucleotides

Conclusions 1. The chromatographic behavior of the dinucleotides of an RNA hydrolysate in thin layers of ECTEOLA- and DEAE-cellulose and on a cellulose powder has been studied. The Rf values of the four dinucleotides A_pC_p, A_pU_p,G _pC_p andG _pU_p in various solvent systems have been determined. It has been shown that in a thin layer of DEAE cellulose the dinucleotide fraction of a ribonuclease hydrolysate is separated into the four individual components.2. Conditions for the separation of authentic mixtures of dinucleotides and of mixtures of mono- and dinucleotides have been found.Khimiya Prirodnykh Soedinenii, Vol. 5, No. 4, pp. 287–291, 1969     

The use of thin-layer chromatography in investigations of the adsorption of some aromatic hydrocarbons

Summary Using adsorption TLCR_M values were measured for six aromatic hydrocarbons on silica gel G. The following binary mobile phases were used: trichloroethylene+benzene, carbon tetrachloride+benzene, n-heptane+trichloroethylene and n-heptane+benzene. The obtained results are presented graphically and compared with values calculated theoretically. Generally a good agreement was found in the R_M values calculated and measured. This confirms the applicability of Ocik's equation descrbed earlier in the examination of interactions between the components of adsorption systems. The analysis of the variations of various parameters of the equation can supply important data concerning these interactions.     

Influence of chamber saturation in thin-layer chromatography on theoretical and experimental parameters of mixture separations

The influence of chamber saturation in thin-layer chromatography on theoretical and experimental parameters of mixture separations were examined. Five different types of chambers for development of chromatograms were taken into consideration. The relation found experimentally differed widely from that calculated using O?cik's equation for different method of carrying out of the chromatographic process. The investigations presented here show the possibility of choosing chromatographic chambers which are optimum for theoretical studies on the process of thin-layer chromatography.     

An optimization function and its application to the multidimensional thin-layer chromatography of protein amino acids

The multicomponent mobile-phase systems in thin-layer chromatography (TLC) can be optimized by using an overall figure of merit for the separation. To simulate the normally subjective appraisals of resolution in TLC, the figure of merit (FOM) is based on an equation which defines the extent of separation of pairs of spots. Contributions to the FOM range from zero at complete overlap to a maximum value with complete resolution. A small degree of spot overlap causes only a limited decrease in the FOM but the decrease is rapid with deteriorating resolution. The approach is shown to be effective in simplex optimization of the separation of 17 amino acids by two-dimensional TLC on cellulose plates with two 4-component solvent systems, one basic and one acidic. The problem was considered as two distinct one-dimensional separations. The acidic mobile phase was optimized first. The eight spots left unseparated were completely resolved by the basic phase. Optimum mobile-phase compositions were: 12.0/6.0/1.52/2.48 (by volume) t-butanol/ammonia (25%)/methyl ethyl ketone/water for the first elution and 10.29/6.82/5.06/ 3.65 n-butanol/acetone/acetic acid/water for the second elution.     

The use of thin-layer chromatography in the assessment of the quality of lutein-containing dietary supplements

Bivariant multiple development thin-layer chromatography technique (BMD–TLC) along with high-performance liquid chromatography–diode array detection–electrospray ionization–mass spectrometry (HPLC–DAD–ESI–MS) analysis was used in determination of lutein or lutein mixed with zeaxanthin in eight dietary supplements. The developed two-step TLC separation procedure combined purification, compaction of samples and separation of the analyzed compounds what significantly shortened and simplified samples preparation. Qualitative analysis was based on co-chromatography with reference substances and HPLC–DAD–ESI–MS analysis. It was revealed that three of eight dietary supplements did not contain lutein. In turn, quantitative analysis with the use of developed TLC conditions along with densitometry showed that the amount of lutein or its mixture with zeaxanthin in the others differed from that claimed by producers.

     

多维液相色谱技术的进展

与一维分离模式相比,多维色谱分离技术的最大特点是可极大地提高峰容量．近几年,随着蛋白质组学的出现尤其是表达谱的开展,对分离技术提出更高的要求．多维高效液相色谱系统以其快速、高效、自动化程度高以及易与质谱等其他技术联用等优势再一次成为研究应用的热点．本文结合本课题组在多维色谱方面的工作介绍了多维色谱技术的发展及应用,重点介绍在蛋白质组学平台中的应用．     

Overpressured thin-layer chromatography

The properties, apparatus and applications of overpressured thin-layer chromatography (OPTLC) have been reviewed. In the Introduction planar chromatography has been briefly characterized, with particular attention to TLC. The general properties of OPTLC and methods of development of chromatograms in this technique have been then given. The construction of chambers and equipment for OPTLC has been described, paying attention to two-dimensional columns. The properties of chambers for OPTLC have been characterized considering the flow of eluent, sorbent-eluent interactions and the efficiency of various systems. OPTLC, TLC and HPTLC have been compared and also a comparison between OPTLC with a constant (linear) eluent flow-rate and with a decreasing eluent flow-rate has been made. Analytical applications of OPTLC have been described and examples of separations of mixtures have been given.     

Practice of thin-layer chromatography

Ohne Zusammenfassung

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Practice of thin-layer chromatography By J.C. Touchstone and M.F. Dobbins, John Wiley & Sons, New York, Chichester, Brisbane, Toronto, 1978