Thin-layer Chromatographic Detection Research Articles

3,5,3′,5′-Tetramethylbenzidine as a spray reagent in the thin-layer chromatographic detection of organochlorine pesticides

3,5,3′,5′-Tetramethylbenzidine as a spray reagent in the thin-layer chromatographic detection of organochlorine pesticides

Influence of phospholipid saturation on classical thin-layer chromatographic detection methods and its effect on amniotic fluid lecithin/sphingomyelin ratio determinations.

We compared seven techniques, commonly used for detection of amniotic fluid phospholipids in thin-layer chromatography, with respect to their sensitivity to saturation of the fatty acid carbon-chain of lecithin. The techniques fell into two classes: sensitive and insensitive; those classed as saturation sensitive were less than or equal to 10% as sensitive to fully saturated lecithin as to lecithin with singly unsaturated acid moieties. Color development increased with the number of carbon-carbon double bonds per molecule but required only a single unsaturated acid ester in either the alpha or the beta position. Mixtures of lecithins with defined saturation, when detected by saturation-sensitive methods, mimicked the uneven coloration of amniotic fluid lecithin bands, supporting the hypothesis that this uneven coloration results from natural saturation heterogeneity. Detection techniques representative of these classes are shown to give widely differing values for the lecithin/sphingomyelin ratio for actual specimens of amniotic fluid.

Thin-layer chromatographic detection of the herbicide asulam in soils and the identification of sulphanilamide as a minor soil degradation product

Thin-layer chromatographic detection of the herbicide asulam in soils and the identification of sulphanilamide as a minor soil degradation product

Genetic activity in Saccharomyces cerevisiae and thin-layer chromatographic comparisons of medical grades of pyrvinium pamoate and monopyrvinium salts

The pamoate, chloride, and iodide salts of pyrvinium, a cyanine dye with anthelmintic properties, were studied in a diploid mitotic recombination and gene conversion assay system (strain D5 of Saccharomyces cerevisiae and a haploid yeast reversion assay (strain XV185-14C). With the use of a thin-layer chromatographic (TLC) detection technique, samples of pyrvinium pamoate from several sources were found to contain different numbers and quantities of impurities. All samples of pyrvinium pamoate and the monopyrvinium salts were recombinogenic in strain D5 and mutagenic in strain XV185-14C; the degree of genetic activity varied among the tested medical grades of pyrvinium pamoate. Monopotassium pamoate was found to be genetically inactive in both strains. Light-catalyzed degradation did not enhance the genetic activity of pyrvinium in either of the yeast strains; the degraded samples were not mutagenic.

Optical brighteners as thin-layer chromatographic detection reagents for glycoalkaloids and steroid alkaloids in Solanum species : II. Blankophor® BA 267%, BBU neu and KU, and Tinopal® CBS-X and 5 BMS-X

Optical brighteners as thin-layer chromatographic detection reagents for glycoalkaloids and steroid alkaloids in Solanum species : II. Blankophor® BA 267%, BBU neu and KU, and Tinopal® CBS-X and 5 BMS-X

Extension of the AOAC multiresidue methodology for the determination of thiocarbamate herbicide residues in foods

AbstractThe internationally recognized AOAC multiresidue method has been extended for the determination of thiocarbamate herbicides in deep frozen vegetables. N,2,6‐trichlorobenzoquinone imine or N‐chloro‐2,6‐dibromobenzoquinone imine was used for thin layer chromatographic detection and semiquantitative determination of these herbicides with a sensitivity of 50 ng/spot.

Thin Layer Chromatography of Metal Ions Complexed with Anils Part - VI

Abstract Thin layer chromatographic detection, separation and determination of Ti(IV), UO2(II), Au(III) and Hg(II) complexes with λ - and β - naphthylanils of methylenediglyoxal have been made on silica gel layers. No locating agent was used as the complex spots were self evident in day light.

The determination of chlorinated long-chain paraffins in water, sediment and biological samples

Methods are described for the routine determination of traces of industrial chloro-n-paraffins having 13–30 carbon atoms and chlorine contents of 42–45% (frw/w), in environmental samples of water, sediments and biota. The procedures are based on thin-layer chromatography detection and measurement. All samples are cleaned up by liquid—solid adsorption chromatography and thin-layer chromatography but those rich in lipids require preliminary solvent extraction. The methods distinguish between chloro-n-paraffins based on long carbon chains (C 20–C 30) and those based on shorter chains (C 13–C 17). The methods cover the ranges 500 ng l −1 to 8 μg l −1 for water (i.e. from about the solubility limit upwards) and 50 μg kg −1 to 16 mg kg −1 for sediments and biota. The precision of the methods ranges from ± 50% relative at the lowest concentrations to ± 12% relative at the highest. Recoveries are about 90% for water, 80% for sediments and between 80 and 90% for biota according to sample type.

Optical brighteners as thin-layer chromatography detection reagents for glycoalkaloids and steroid alkaloids in Solanum species : I. Calcofluor® M2R New

Optical brighteners as thin-layer chromatography detection reagents for glycoalkaloids and steroid alkaloids in Solanum species : I. Calcofluor® M2R New

Thin-layer chromatographic detection of herbicidal thiocarbamates and their sulphoxide and sulphone metabolites

Thin-layer chromatographic detection of herbicidal thiocarbamates and their sulphoxide and sulphone metabolites

Vacuum sublimation of polynuclear aromatic hydrocarbons separated by thin-layer chromatography for detection with shpol'skii low-temperature fluorescence

A method for the vacuum sublimation of polynuclear aromatic hydrocarbons (PAHs) from thin-layer chromatographic plates is described. Low-temperature fluorescence spectroscope, utilizing the Shpol'skii effect, is used for the detection and identification of benzo[a]pyrene, pyrene and benzo[ghi]perylene in samples from different sources. The recoveries of these PAHs were optimized by varying the time and temperature of sublimation.

Precision zone detection in thin-layer chromatography

Precision zone detection in thin-layer chromatography

Thin-layer chromatographic detection of some impurities in cobalt(III) complexes

Thin-layer chromatographic detection of some impurities in cobalt(III) complexes

Thin-layer chromatographic detection of glyphosate herbicide (N-phosphonomethyl glycine) and its aminomethyl phosphonic acid metabolite

Thin-layer chromatographic detection of glyphosate herbicide (N-phosphonomethyl glycine) and its aminomethyl phosphonic acid metabolite

Comparison of thin-layer chromatographic detection methods for histamine from food extracts

The specificity and sensitivity of four visualization reagents, ninhydrin, o-phthalaldehyde (OPT), fluorescamine and o-diacetylbenzene (DAB), for the detection of histamine on thin-layer chromatograms developed in several optimal solvent systems were compared. While the ninhydrin reagent is the most sensitive with a detection limit of 0.4 nmoles of histamine, the DAB and fluorescamine reagents offer the most potential as histamine-specific visualization reagents. The OPT reagent was unsatisfactory because the fluorescent spots developed with this reagent were unstable. Of 19 amines tested in addition to histamine, ninhydrin reacted with 17, fluorescamine with 8 and DAB with 15. Since only histidyl-leucine, octopamine, serotonin and tryptophan interfere in the resolution of histamine in any of the solvent systems used, DAB provides some advantages by not reacting with histidyl-leucine. In addition, with the acetone-ammonia (95:5) solvent system, which adequately separates histamine from all other tested amines, no background interference problems were noted when using DAB as the visualization reagent. Background interference problems with the acetone-ammonia system were evident with the other visualization reagents. The sensitivity of the DAB and fluorescamine methods (4 nmoles of histamine) allows both reagents to act as semi-quantitative screening agents for potentially toxic levels of histamine in food extracts. With a variety of food samples, DAB visualization following development in acetone-ammonia (95:5) was the optimal thin-layer chromatographic method.

The van URK-Salkowski reagent — a sensitive and specific chromogenic reagent for silica gel thin-layer chromatographic detection and identification of indole derivatives

The chromogenic reagent described has been tested with seventy-nine indole derivatives and found to be very sensitive and indole-specific. The lower limit of detection on silica gel thin-layer plates was between 25 and 50 ng for most indoles. Phenols and hydroxy-, and amino-benzoic acids, hydroxy-, and methoxy-cinnamic acids did not yield chromophores with the exception of p-amino-benzoic acid and p-hydroxy-cinnamic acid which gave yellow and pink chromophores at concentrations greater than 1 and 2 μg. Although many of the C-3 substituted indoles such as indole-3-acetic acid and tryptamine had colors in the reddish-violet-blue color region, most exhibited sufficient color differentiation to allow their identification by thin-layer chromatography. The procedure was simple and required only 10 min from the time of spraying the thin-layer plate until full color development was reached. The colors had a wide spectral range from yellow of the indole-3-glyoxylamide chromophore to blue of the melatonin chromophore, and were extremely stable.

Thin-layer chromatographic detection of quinine, morphine and poly-drugs.

Journal Article Thin-layer chromatographic detection of quinine, morphine and poly-drugs. Get access K K Kaistha, K K Kaistha Search for other works by this author on: Oxford Academic Google Scholar R Tadrus R Tadrus Search for other works by this author on: Oxford Academic Google Scholar Clinical Chemistry, Volume 22, Issue 11, 1 November 1976, Pages 1936–1937, https://doi.org/10.1093/clinchem/22.11.1936 Published: 01 November 1976

Vinyloge acylverbindungen : XV. Dünnschichtchromatographischer nachweis toxikologisch relevanter 2-halogenvinylketone

Vinylogous acyl compounds. XV. Thin-layer chromatographic detection of 2-halovinyl ketones with toxicological relevanceThe basic ring-opening of 1-(2-acylvinyl)-pyridinium salts yielding azaoxonol dyes and the spontaneous dehydrohalogenation of 1-(2-acylvinyl)-4-(4-nitrobenzyl)-pyridinium salts to deeply coloured anhydrous bases underlie two sensitive thin-layer chromatographic detection procedures for 2-halovinyl ketones (RCOCHCHX). The detection limits are 0.06 μg on successive use of methanolic solutions of pyridine and potassium hydroxide as spray reagents and 0.02 μg on spraying with an acetonic solution of 4-(4-nitrobenzyl)-pyridine. RF values of twenty-five trans- and twelve cis-configurated 2-halovinyl ketones for three solvent systems are given.

Thin Layer Chromatographic Detection and Indirect Gas Chromatographic Determination of Three Carbamate Pesticides

Carbamate pesticide residues are extracted from vegetables and fruits with methylene chloride. The extracts are spotted on silica gel plates and the pesticides are detected by an enzymatic inhibition technique. For quantitative determination, aliquots of the methylene chloride extracts are evaporated to dryness in a rotary evaporator. After the residues are dissolved in ethanol, 0.5N NaOH is added in the hydrolysis step. To remove a number of possible interferences the hydrolyzed phenols are steam-distilled and treated with 1-fluoro-2,4-dinitrobenzene and/or 4-chloro-alpha,alpha,alpha-trifluoro-3,5-dinitrotoluene to form the ether derivatives. Efficiency in the conversion of the phenolic moieties to the phenyl ethers is about 100%. The resulting electron-capturing derivatives enable the carbamate pesticides to be detected in vegetables and fruits at the 0.05 ppm level. Recoveries of 90-94% were obtained from vegetables and fruits fortified with 0.5-2.0 ppm carbaryl, Mesurol, and propoxur.

Thin-layer chromatographic detection of some systemic fungicides and their metabolites

Thin-layer chromatographic detection of some systemic fungicides and their metabolites