Ninhydrin solution light

Then remove the strip and dry it in a stream of cold air, either from a blower, or by pinning it to the lower edge of a fume-cupboard window having a vigorous draught already in operation. Then spray the strip lightly but uniformly with the ninhydrin solution (D) in a fume-cupboard, and dry as before. 

When the developing solvent reaches a few centimeters from the top of the chromatogram, remove the paper from the jar and allow it to dry in a hood. Remove the staples and spray the paper lightly with ninhydrin solution. Allow it to dry in a hood for 10 minutes. The color may be developed by placing the chromatogram in an oven (100°C for 10 min) or at room temperature for 1 to 2 hours. All the spots should be circled with a pencil, as they will fade with time. Describe in your notebook the color of each spot. 

Absorbance of ninhydrin solution silk fabrics after heating, 120-22,125 silk fabrics exposed to light, 123-24 Accelerated aging of cellulosic textiles, effect of... 

Sample and various reference standards are spotted on three plates of Merck Silica Gel 60. Plates 1 and 2 are developed with butanone saturated with water plate 3 is developed with 45 45 8 CHCl3/MeOH/conc. NH4OH. After development, all plates are dried. Plate 1 is not heated, plate 2 is heated at 15(PC for 30 min, and plate 3 is heated at 80 C until free of ammonia odor. All three are exposed for 2 min to a chlorine gas atmosphere, stored in a vacuum desiccator until free of excess chlorine, and sprayed with the visualizer, a mixture of 4,4 -methylenebis-(iVW-dimethylaniIine) (2.5 g dissolved in 10 mL acetic acid, diluted with 50 mL water, and filtered), KI solution (100 mL of a 5% solution), and ninhydrin solution (15 mL of a 0.5% solution in 90 10 H2O/HOAC) The three visuahzer components are mixed just before use. The compounds appear as dark blue spots on a light blue background. Plate 1 serves to separate monoethanolamide and isopropanolamide from all other components plate 2 resolves amides from amines, which remain at the origin plate 3 differentiates all compounds except diethanolamide and polydiethanolamide. 

To perform the ninhydrin test a solution of ninhydrin in ethanol or acetone (0.2% w/v) is sprayed lightly over the plate. Brown to purple colors develop slowly (within 1-2 min) upon heating to 60-90 °C. The spray is stable for several weeks. 

Reagent Solution B. A solution of ninhydrin (2.5 g) in absolute EtOH (50 ml) is prepared and maintained in a light-proof container, preferably under inert atmosphere. 

Ninhydrin (1,2,3-triketohydrindene monohydrate). Widely available chemical, light-sensitive. Ninhydrin reacts with free amines (2 1 molar ratio), giving a purple product (Ruhemann s purple resonance structure). Used for a qualitative test to determine the presence of aliphatic amines on the agarose beads as a 0.2% w/v solution in ethanol (see Note 4). Hazards Harmful if swallowed skin, eye, and respiratory irritant. Toxicity data LD50 78 mg/kg intraperitoneal, mouse. Should be handled in a fume hood with safety glasses and gloves. 

Visualization of the spots was done by examination under UV-light or spraying with ninhydrin. The color-forming reaction with nitrobenzylpyridine (NBP) (see 5.2.1) has been used by dipping the chromatograms in solutions of NBP followed by heating at 90° and treating with triethylamine [68]. 

The spots were located by examination under UV light or spraying with one of following solutions (detection limits in yg) fluorescamine (0.5), ninhydrin (1), NBP followed by heating and treatment with a base (5) [51,63a], and 0.5% iodine in chloroform. Visualization using 4-pyridine-carboxaldehyde 2-benzothiazolyl hydrazone has been described under 5.2.1. 

To prepare the ninhydrin reagent, ninhydrin (2 g) and hydrindantin (300 mg) are dissolved in dimethyl sulfoxide (DMSO) (75 ml) in a foil-covered 400 ml flask (to exclude light) and are adjusted to 100 ml with 4 M lithium acetate buffer. The jar is stoppered with a rubber bung with inlet and outlet tubes, and the reagent is flushed with 02-free N2 for 30 minutes. The operations must be done in a fume hood. The final solution is then stored sealed at room temperature. Ninhydrin is toxic and stains the skin, so gloves should be worn at all times. 

In the amino acid analyzer, the components of the hydrolysate are dissolved in an aqueous buffer solution and separated by passing them down an ion-exchange column. The solution emerging from the column is mixed with ninhydrin, which reacts with amino acids to give the purple ninhydrin color. The absorption of light is recorded and printed out as a function of time. 

If the solutes fluoresce (aromatic compounds), they can be detected by shining an ultraviolet light on the plate. A pencil line is drawn around the spots for permanent identification. Color-developing reagents are often used. For example, amino acids and amines are detected by spraying the plate with a solution of ninhydrin, which is converted to a blue or purple color. After the spots are identified, they may be scraped off and the solutes washed off (eluted) and determined quantitatively by a micromethod. 

The spots are identified under UV-light 366 nm and with spray reagents, like 0,2% ninhydrin in ethanol, 0.1 ml IM HCl + 300 ftl of 10% hexachloroplatinate (IV) acid solution + 20 ml of acetone + 0.2 ml of aqueous 20% Kl- solution and 1% starch solution/acetic acid/O.lM la-solution (100 8 1) (see Table 3). The chromatographic details concerning decomposition or spot colors were discussed. 

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