Paper chromatography quantitative methods

Saeman, J.F., Moore, W.E., and Millet, M.A. 1963. Sugar units present. Hydrolysis and quantitative paper chromatography. In Methods in Carbohydrate Chemistry, Vol. 3, Cellulose (R.L. Whistler, ed.) pp. 54-69. Academic Press, New York. 

Gas-flow counting is a method for detecting and quantitating radioisotopes on paper chromatography strips and thin-layer plates. Emissions are measured by interaction with an electrified wire in an inert gas atmosphere. AH isotopes are detectable however, tritium is detected at very low (- 1%) efficiency. 

Specifications, Analysis, and Toxicity. Dicyandiamide is identified quaHtatively by paper chromatography and quantitatively by ultraviolet spectrometry of the chromatogram. More commonly, total nitrogen analysis is used as a purity control or the dicyandiamide is converted by hydrolysis to guanylurea, which is determined gravimetrically as the nickel salt (50). Methods based on the precipitation of silver dicyandiamide picrate are sometimes used (51). Dicyandiamide can also be titrated with tetrabutylammonium hydroxide ia pyridine solution. Table 4 gives a typical analysis of a commercial sample. Dicyandiamide is essentially nontoxic. It may, however, cause dermatitis. 

Chromatography is one of the most powerful and widely used means for separating mixtures, because it is often inexpensive and it can be used to provide quantitative as well as qualitative information. The simplest method is paper chromatography. A drop of solution is placed near the bottom edge of the stationary phase, an absorbant support, such as a strip of paper. The mobile phase, a fluid solvent, is added below the spot and the solvent is absorbed on the support. As the mobile phase rises up the stationary phase by capillary... 

The development of the open-column methods, ie paper chromatography (in the 1940 s) and thin-layer chromatography (in the 1950 s) greatly improved the speed and resolution of lc, but there were still serious limitations compared to modern lc methods, in that analysis times were long, resolution was poor and quantitative analysis, preparative separations and automation were difficult. 

To determine the relative amounts of neomycins B, C and neamine by a radio chemical method, Kaiser 2 separated the -labelled N-acetyl derivatives by paper chromatography and quantitated the chromatograms by liquid scintillation counting. A coefficient of variation of 3.6% was obtained. 

The column chromatography technique using Dowex 50 ion-exchange resin, introduced in 1951 (M2) and improved in 1954 (M3) by Moore and Stein, first made possible the precise quantitative analysis of amino acids liberated in the course of acid hydrolysis of urine. Similar results were also obtained by Muting in 1954 (M4), who used paper chromatography methods. In this procedure amino acids were quantitatively determined after staining on the paper and elution of the resulting spots. 

The anthocyanin profile of the flowers of Vanda (Orchidaceae) was investigated with a similar technique. Flowers (2 kg) were extracted with 101 of methanol-acetic acid-water (9 l 10,v/v) at ambient temperature for 24 h. The extract was purified by column chromatography, paper chromatography, TLC and preparative RP-HPLC. Analytical HPLC was carried out in an ODS column (250 X 4.6 mm, i.d.) at 40°C. Gradient conditions were from 40 per cent to 85 per cent B in 30 min (solvent A 1.5 per cent H3P04 in water solvent B 1.5 per cent H3P04, 20 per cent acetic acid and 25 per cent ACN in water). The flow rate was 1 ml/min and analytes were detected at 530 nm. The chemical structures of acylated anthocyanins present in the flowers are compiled in Table 2.90. The relative concentrations of anthocyanins in the flower extracts are listed in Table 2.91. It can be concluded from the results that the complex separation and identification methods (TLC, HPLC, UV-vis and II NMR spectroscopy, FAB-MS) allow the separation, quantitative determination and identification of anthocyanins in orchid flowers [262],... 

Three recent reviews specifically cover HPLC methods for quantitating riboflavin in foods. In addition to HPLC methods, Nielsen (81) summarized paper chromatography, TLC, and open-column chromatography procedures for quantitating total riboflavin and the individual vitamers in foods, pharmaceuticals, and biological samples. Russell (44) included a brief discussion of the standard methods, along with HPLC and flow injection analyses published between 1990 and 1994 for total riboflavin and the individual vitamers in foods. Ball (45) reviewed HPLC methods for quantitation of riboflavin, as well as chemical and microbiological riboflavin assays for foods. 

Three recent reviews included HPLC methods for food folacin. Mullin and Duch (122) reviewed selected HPLC methods for determining the folacin vitamers in foods, biological tissues, and pharmaceuticals. They also included paper chromatography, TLC, and microbiological methods. Russell (44) reviewed selected HPLC methods published between 1990 and 1994 for folacin quantitation in foods, including a brief review of the reference methods. Ball (45) reviewed HPLC and microbiological methods for the quantitation of folacin in food samples. 

From a review of the available literature it is clear that methods based on thin layer chromatography are frequently being used by various workers in the field for the quantitation of pesticides. In the present paper the quantitative TLC technique using densitometry is described in detail for the determination of pesticides in various tissues pertaining to actual cases of poisoning. 

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