Paper chromatography detection

Also Tojo and Uenoyama (T2) by means of paper chromatography detected neither 5-hydroxyanthranilic acid nor its conjugate forms in urine of senile cataract patients. They found, however, an ethanol-extractable substance giving a positive ninhydrin reaction and Rf value coinciding with that of tryptophan. The oral administration of a dose of anthra-nilic acid did not alter their findings. 

This recrystallised acid is pure in the norm y accepted sense of the word, namely it has a sharp m.p. and gives on analysis excellent values for carbon, hydrogen and nitrogen. If however it is subjected to one-dimensional paper chromatography (p. 53), the presence of traces of unchanged anthranilic acid can be detected, and repeated recrystallisation is necessary to remove these traces. 

Hydrazinothiazoles form stable complexes with Mn ", Ni. Cd Cu ", Co ", Fe ", and Fe " this property was used to detect small amounts of these salts in mixtures by paper chromatography (547, 548). Some infrared features of the complexes formed with the silver salts and with the mercuric salts have been reported (1583). 

Hydantoin itself can be detected ia small concentrations ia the presence of other NH-containing compounds by paper chromatography followed by detection with a mercury acetate—diphenylcarba2one spray reagent. A variety of analytical reactions has been developed for 5,5-disubstituted hydantoias, due to their medicinal iaterest. These reactions are best exemplified by reference to the assays used for 5,5-diphenylhydantoiQ (73—78), most of which are based on their cycHc ureide stmcture. Identity tests iaclude the foUowiag (/) the Zwikker reaction, consisting of the formation of a colored complex on treatment with cobalt(II) salts ia the presence of an amine (2) formation of colored copper complexes and (3) precipitation on addition of silver(I) species, due to formation of iasoluble salts at N. ... 

The amino group is readily dia2oti2ed in aqueous solution, and this reaction forms a basis for the assay of sulfas. Aldehydes also react to form anils, and the yellow product formed with 4-(dimethylamino)hen2a1dehyde can be used for detection in thiu-layer and paper chromatography. Chromatographic retention values have been deterrnined in a number of thiu layer systems, and have been used as an expression of the lipophilic character of sulfonamides (23). These values have corresponded well with Hansch lipophilic parameters determined in an isobutyl alcohol—water system. 

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. 

Sufficient data are not yet available to allow evaluation of the relative merits of palladium-on-carbon and degassed Raney nickel catalysts. Comparable yields of 2,2 -biquinolines have been obtained by both methods under suitable conditions but the percentage conversions with degassed Raney nickel have been found to be much lower, reflecting the extent of side reactions with this catalyst. However, work in this laboratory has shown that the reaction of quinoline with palladium-on-carbon is not free from complications for example, at least three products in addition to 2,2 -biquinoline have been detected by paper chromatography. 

The detection of microgram quantities of pyrethrins, cinerins, keto alcohols, and chrysanthemum acids by paper chromatography and by application of these techniques to a study of possible metabolites enabled certain tentative conclusions that imply hydrolysis in insects of a large portion of the radioactive pyrethrins and synergists to corresponding keto alcohols and chrysanthemum acids. 

Spectrophotometric resolution for the discrimination of individual colorant molecules found in mixtures is lower than that of chromatographic techniques such as TLC or HPTLC and even low-cost paper chromatography. More expensive but more accurate determinations may be made by RP-HPLC, IP-HPLC with UV-Vis, and diode array detection. ... 

The bearing which these discoveries have had on the elucidation of the structure of ribopolynucleotides will be discussed later. It is important to stress here, however, that, for most purposes, the older methods of preparing nucleotides have been superseded by procedures which yield separate isomers of each. Of the techniques mentioned above, paper chromatography iB mainly of analytical value, and is the most convenient method for the qualitative detection of isomeric adenylic acids. The only disadvantage of this method is that the isomers are not completely separable from muscle adenylic acid. The presence of the latter, however, can be readily detected by hydrolyzing it to adenosine by means of the specific 5-nucleotidase present in snake venoms,66 or by deamination by a specific enzyme... 

Cellulose anion-exchange paper chromatography with 5% acetic acid-n-propanol (5 1) gave good separation, detected by U.V. light, of aspirin (Rf. 0.07) from salicylic acid (Rf. 0.51).107... 

In 1964, Netrawali et al.66 described fluorescence measurements of calcium leucovorin in NaHC03 solution after paper chromatography and reaction with acidic orcinol. The gray-blue fluorescent species formed on the developed paper-gram was very sensitive for leucovorin, showing a detection limit of 0.1 yg. In the eluting solution, however, the required concentration increased to 0.5 pg. Recovery by this method was 100 15%, and results obtained from fluorescence were lower by 10 to 20% than those obtained by microbiological methods. 

Paper chromatography has been used to separate and detect pseudoephedrine hydrochloride from other pharmacologically active amines. Whatman No. 1 paper developed in n-butanol water 95% acetic acid (4 5 1), n-butanol toluene water 95% acetic acid (10 10 5 5), ethyl acetate water 95% acetic acid (3 3 1), or chloroform water 95% acetic acid (10 5 4) gave Rf values of 0.73, 0.35, 0.57, and 0.52 for pseudoephedrine hydrochloride respectively. Visualization of pseudoephedrine hydrochloride was done by spraying the chromatogram with 0.5% bromcresol green in methanol or 0.2% nin-hydrin in acetic acid butanol 5 95.30... 

Reagents used for the visualisation of amino acids on the dried chromatogram may be applied either by spraying or dipping. Those commonly used produce intensely coloured bands with approximately 20 nmol of each amino acid for paper chromatography and 5 nmol for thin-layer separations, although smaller amounts can be detected. 

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],... 

Cinnamyl anthranilate can be assayed by a method based on ester hydrolysis. Bulk samples of food-grade cinnamyl anthranilate have been analysed for purity by thin-layer chromatography and high-performance liquid chromatography. A method has been described for determining the content of this compound in food products by steam distillation followed by paper chromatography and examination under ultraviolet light it has a limit of detection of 1 pg (lARC, 1983). 

---