Thin-layer chromatography of slightly soluble substances at elevated temperature

Székely, G.; Baumgartner, Peter

doi:10.1016/s0021-9673(00)95278-6

Cited by 13 publications

(4 citation statements)

References 5 publications

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“…Some typical R f values of water-soluble dyestuffs (72) are recorded in Table 2 along with the v max value and percent recovery of each dye. Slightly soluble food dyes can be studied at elevated temperatures (102). Twenty-two high-boiling organic solvents were used as eluents, including hydrocarbons and esters.…”

Section: B Food Dyesmentioning

confidence: 99%

Synthetic Dyes

Gupta¹

2003

Handbook of Thin-Layer Chromatography

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Section: B Food Dyesmentioning

confidence: 99%

Synthetic Dyes

Gupta¹

2003

Handbook of Thin-Layer Chromatography

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“…Chromatographic analysis of printing inks has importance in forensic sciences, in the study of historically valuable works, in quantifying the toxicity of inks etc. [43][44][45][46][47][48][49][50]. Chromatographic techniques for the printing inks are usually used as the first and preparative stage of the analysis, and it is usually followed by thermogravimetric or elemental analysis of the separated substances [47].…”

Section: Influence Of Coating Pigment Chemistry and Morphologymentioning

confidence: 99%

Influence of Coating Pigment Chemistry and Morphology on the Chromatographic Separation of Offset Ink Constituents

Rousu,

Gane,

Eklund

2001

Trans. Of the XIIth Fund. Res. Symp. Oxford, 2001

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This work is aimed at characterising the chromatographic action of some typical paper coating pigments in relation to the separation and fractionation of offset printing ink components during absorption into the coating void structure, with particular emphasis given to the chemical and structural parameters of the pigments. The separation phenomenon was studied experimentally using primarily large-scale model systems based on a modified thin-layer chromatography method. The separation of the ink constituents was detected directly from the absorption path using Fourier Transform Infra-Red (FTIR) microscopy. The coatings were characterised for their physical properties using mercury porosimetry, and the absorbing fluids for their viscosity and surface energy. The ink-coated paper contact on the realistic scale was evaluated using the concept of ink-on-paper tack development. Coating pigments used in the work included typical paper coating grade ground calcium carbonates, fine clays of different origins, as well as talc and precipitated calcium carbonate. The choice of pigments provided the possibility to investigate independently the chemical and physical aspects of pigment properties on the constituent fluid separation. Ink chemicals included representatives of the most typical offset ink components; namely mineral oil, linseed oil, ink resins and ink pigment. A blend of mineral and linseed oils was used as the main test fluid. The differential interaction or adsorption-desorption on the pigments leads to separation of the mixture of mineral and vegetable (in this case linseed) oils as they are absorbed into the pigment coating structure, where the more polar linseed oil is preferentially retarded in the structure composed of the more polar pigments. The degree of the separation is directly proportional to the surface area of the pigment within a group of chemically and morphologically identical pigments. It is also affected by the surface chemistry of the pigment but more so in comparing dispersed and undispersed pigments, and polar versus non-polar rather than between the chemically different hydro- philic dispersed pigments. Pigment morphology strongly influences the macroscopic flow behaviour due to changes in physical porous structure (pore size, porosity, tortuosity). The macroscopic flow behaviour, which is affected by all of the above mentioned structural and chemical parameters of both the solid and liquid phases, proved to be a universal parameter determining the separation efficiency of the oils by affecting the retention time. Added ink resins in the oil mix retards the overall absorption rate of the oils, but does not affect the separation tendency of the oils in most of the cases studied, except in cases where less polar pigments or dispersions are involved. Adding latex into the coating structure, on the other hand, creates an additional gradient for separation of the oils as oil diffusion into the latex provides further selectivity.

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“…in general [17,18], and in the separation of indigo and a limited number of vat dyes Table 1 Vat dyes used in t.1.c. analysis and intermediates in particular [19], has been reported.…”

Section: Introductionmentioning

confidence: 96%

“…It has been reported that high-temperature chromatography is especially suitable for the evaluation of substances of low solubility [12,19]. Since vat dyes are quite stable at elevated temperature with limited solubility, it is clear that a high-temperature system could be useful to separate and evaluate vat dyes by t.1.c.…”

Section: Introductionmentioning

confidence: 99%

The thin layer chromatography of vat dyes

Bide

Choi

1992

Journal of the Society of Dyers and Colourists

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The identification and separation of vat dyes by thin layer chromatography has been investigated with reducing and non‐reducing systems. The results showed that the chromatograms on silica gel plates obtained by non‐reducing systems at 100 or 120°C were fast, reproducible and easy to control. Nine non‐reducing eluents were developed, producing good migration and resolution of 21 vat dyes. Analyses of the chromatograms revealed that the Rf, values varied with the temperature of the system, the chemical structure of the vat dyes and the nature of adsorbent, as well as with the eluents used. The effects of molecular masses of the vat dyes on the Rf values were less significant. Despite the successful use of a novel reducing agent for vat dyes, the chromatography of reduced dye was largely unsatisfactory. The use of reversed‐phase t.l.c. plates was examined and showed little benefit.

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Thin-layer chromatography of slightly soluble substances at elevated temperature

Cited by 13 publications

References 5 publications

Synthetic Dyes

Synthetic Dyes

Influence of Coating Pigment Chemistry and Morphology on the Chromatographic Separation of Offset Ink Constituents

The thin layer chromatography of vat dyes

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