Spectrophotometric determination of neomycin sulphate in tablets form via reaction with ninhydrin reagent

A new, sensitive, simple and cheap spectrophotometric method for the determination of Neomycin Sulphate (NEO) in pharmaceutical forms has been developed. The method is based on the reaction between NEO and NIN in basic medium. The maximum absorbance was at 574 nm. The conditions affecting the reaction were optimized. Under the optimal conditions, the calibration curve was linear over the range of 0.0002-0.0011 mol/L. The limit of detection and limit of quantification were 5.423×10-6 mol/L, and 1.643×10-5 mol/L, RSD% of seven replicate was 0.8217- 0.8321% and Rec% was between 99.2168-100.8857%. The proposed method was successfully applied to the determination of NEO tablets form.

Existing problems and ways of their solution in the analysis of amino acid composition

For obtain accurate aminoacids analysis results for peptide samples it is need to pay attention for method of analysis and method of sample preparation. Now some samplpreparation methods are known: acid and basic hydrolysis. In this article the comparison of two methods of aminoacids analysis were observed: pre-column or post-column derivatization. Analysis of lysine in lysine sulphate was studied, results were compared with control samples. For pre-column derivatization o-phthalic anhydride was used, and for post-column derivatization ninhydrin reagent was used. In experimental part advantages of post-column derivatization was shown and more accurate results were obtained. Chromatographic separation, derivatization and detection were carried out on aminoacids analisators Hitachi (Japan) и Sykam (Germany). Samplepreparation methods were observed on valine and threonine analysis using postcolumn derivatization with ninhydrin reagent. The effect of pH adjustment after acid hydrolysis was studied. Basic solution addition best results in comparison with sample evaporation and reconstitution were shown. For final sample analysis optimal methods of analysis and samplepreparation were chosen. Results were compared with results of European Accredited Laboratory.

Modified Ninhydrin reagent for the detection of amino acids on TLC plates

Ninhydrin is the most well known spray reagent for identification of amino acids due to its high sensitivity. But, it produces same purple/violet color with all amino acids, except proline and hydroxy proline. A new spray reagent, para bromobenzoic acid has been introduced here which produces distinguishable colors with the amino acids with moderately high sensitivity (0.01-1.0) μg. A probable mechanism for such color formation has also been proposed.

Ninhydrin-based spectrophotometric assays of trace cyanide

The extreme toxicity of cyanide, its wide industrial application as well as its continued illegal use generate research interest in different fields of science, imposing multidisciplinary approach to study cyanide poisoning. We show here that the reaction between cyanide and ninhydrin can be performed at ambient conditions; however, the ninhydrin reagent has to be freshly prepared in oxygen free solvent. Besides, we show that the reading of the absorbance at 485 nm might be more suitable and reliable than that at 590 nm, where the pH-dependent blue colored cyanide-ninhydrin adduct is less stable. Ninhydrin-based color reagent can be used to quantify the cyanide released from plant seeds. In sodium carbonate medium, the proposed assay is fast, cheap and environmentally friendly

Sequence Determination of a Novel Tripeptide Isolated from the Young Leaves of Azadirachta indica A. Juss

The neem tree has long been recognized for its unique properties, both against insects and in improving human health. Every part of the tree has been used as a traditional medicine for household remedy against various human ailments, from antiquity. Although the occurrence of various phytochemicals in neem has been studied, we have identified the presence of a novel tripeptide in the young leaves of neem using a simple and inexpensive paper chromatographic method, detected by Cu(II)-ninhydrin reagent. The peptide nature of the isolated compound is confirmed by spectral studies. The sequence of the peptide is determined using de novo sequencing by tandem MS after purification.