Identification thin layer chromatography

Also highly nitrated compounds can be detected and identified by means of donors, such as hydrocarbons. Their identification was suggested by the method of thin-layer chromatography [103]. A method of rapid detection, of explosives such as TNT, TNB, Picryl chloride, wi-DNB, Tetryl in the form of charge-transfer complexes with aromatic amines, such as aniline, dimethylaniline, toluidines, anisidines, naphthylamines, benzidine etc. was developed by Dwivedy et al. [104]. The authors used for identification thin-layer chromatography establishing Rf values for model complexes. 

Paints, Varnishes, and Lacquers Questioned Documents Systematic Drug Identification Thin-Layer Chromatography Volatile Substances... 

Creatinine. Electrophoresis Principles Isoelectric Focusing. Enzymes Enzymes In Physiological Samples Industrial Products and Processes Enzyme Assays. Forensic Sciences Alcohol In Body Fluids DNA Profiling Systematic Drug Identification Thin-Layer Chromatography. Immunoassays Applications Forensic. Microscopy Applications Forensic. Nucleic Acids Electrochemical Methods. Polymerase Chain Reaction. Spectrophotometry Oven/lew Biochemical Applications. 

See also Cosmetics and Toiletries. Forensic Sciences Explosives Fibers Gunshot Residues Paints, Varnishes, and Lacquers Systematic Drug Identification. Thin-Layer Chromatography Overview Principles Plate Technology Method Development. 

See also Clinical Analysis Sample Handling. Derivatization of Analytes. Forensic Sciences Systematic Drug Identification Thin-Layer Chromatography. Fourier Transform Techniques. Gas Chromatography Mass Spectrometry Forensic Applications. Immunoassays, Applications Clinical Forensic. Liquid Chromatography Normal Phase Reversed Phase. Spectrophotometry Pharmaceutical Applications. 

Analysis. Dilute aqueous solutions of hydroxyhydroquiaone turn blue-green temporarily when mixed with ferric chloride. The solutions darken upon addition of small amounts, and turn red with additions of larger amounts of sodium carbonate. Derivatives used for identification are the picrate, which forms orange-red needles (mp of 96°C), and the triacetate (mp 96—97°C). Thin-layer chromatography and Hquid chromatography are well suited for the quahtative and quantitative estimation of hydroxyhydroquiaone (93,94). 

Paper and Thin-Layer Chromatography. Both of these techniques aie separation methods useful for dye identification. The dyes are... 

The development and adaptation of procedures for the separation, isolation, purification, identification, and analysis of the components of the pyrethrum mixture have been studied and evaluated. Results of studies to determine the molar extinction coefficient of pyrethrin I as well as a gas chromatographic procedure for the determination of pyrethrins are reported. The use of chromatographic separation procedures (including partition, adsorption, gas, and thin-layer chromatography), colorimetry, and infrared spectrophotometry are discussed. 

Many impurities are present in commercial caprolactam which pass into the liquid wastes from PCA manufacture from which caprolactam monomer may be recovered. Also, the products of die thermal degradation of PCA, dyes, lubricants, and other PCA fillers may be contained in the regenerated CL. Identification of die contaminants by IR spectroscopy has led to the detection of lower carboxylic acids, secondary amines, ketones, and esters. Aldehydes and hydroperoxides have been identified by polarography and thin-layer chromatography. 

Reactions can be exploited more speciHcally if it is known that particular functional groups are present [cf. Chapter 2]. They still do not allow direct identification, but they increase the specificity of the evidence. The chromatographic separation carried out before detection also contributes to this. This reduces the number of potential components. However, this does not exclude the possibility that there might be several substances in the particular part of the chromatogram involved. This not only applies to thin-layer chromatography but also applies with equal force to other microanalytical separation methods (GC, HPLC). 

Marutoiu C, Sarbu C, Vlassa M, et al. 1986. A new separation and identification method of some organophosphorus pesticide by means of temperature programming gradient thin-layer chromatography. Analysis 14 95-98. 

The identification of the target colorant is done directly by UV-Vis spectrometry (if the colorant is unique) or by a previous separation from a mixture. The most available techniques are planar chromatography (paper chromatography and thin layer chromatography) and, especially, high performance liquid chromatography... 

Oka, H. et al., Identification of unlawful food dyes by thin-layer chromatography-fast atom bombardment mass spectrometry, J. Chomatogr. A, 674, 301, 1994. 

PLC is used for separations of 2 to 5 mg of sample on thin-layer chromatography (TLC) plates (0.25-nun layer thickness) or high-performance TLC (HPTLC) plates (0.1-mm thickness). In these instances, the method is termed micropreparative TLC. The isolation of one to five compounds in amounts ranging from 5 to 1000 mg is carried out on thicker layers. PLC is performed for isolation of compounds to be used in other tasks, i.e., further identification by various analytical methods, such as ultraviolet (UV) solution spectrometry [1] or gas chromatography/mass spectrometry (GC/MS) [2], obtaining analytical standards, or investigations of chemical or biological properties [3]. 

Morlock, G. andKovar, K.-A., Detection, identification, and documentation, inHand-book of Thin Layer Chromatography, 3rd ed., Sherma, J. and Fried, B., Ekls., Marcel Dekker, New York, 2003, pp. 207-238. 

The identification of separated componnds is primarily based on their mobility in a snitable solvent, which is described by the Rp valne of each compormd. Kowalska et al. have nicely discnssed in greater detail the theory of planar chromatography and separation efficiency parameters in Chapter 2 of the third edition of the Handbook of Thin-Layer Chromatography, published in 2003. 

Visualization Techniques for Thin-Layer Chromatography.892 Qualitative Identification and Nicroreaction Techniques it ... 

TLC plates are of particular interest as substrates for spectroscopy (i) as a storage device for offline spectroscopic analysis (ii) for efficient in situ detection and identification and (iii) for exploitation of spectroscopic techniques that cannot be used in HPLC. Thin-layer chromatography combined with HR MAS (NMR) can be used for compound identification without the need for elution from the stationary phase [413]. Recently also TLC-XRF was found suitable for in situ TLC imaging of elements [414]. The combination... 

Pereira, A., Pereira, M, M., Free amino acids in green coffee from Huambo (Angola). Separation and identification by electrophoresis and thin layer chromatography, Coll. Sc 1. Int. Cafe, 8, 545, 1977. (CA92 196460s)... 

Schweppe, H. (1989), Identification of red madder and insect dyes by thin layer chromatography, in Historic Textile and Paper Materials II Conservation and Characterization, ACS, pp. 111-219. 

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