| 摘要 |
PURPOSE:To make it possible to prepare and preserve the ninhydrin reagent under ordinary atmosphere without necessitating nitrogen gas, by adding mercaptan compound to a solution containing ninhydrin or mixture of ninhydrin and hydrindantin. CONSTITUTION:A mixture is formed by adding 0.2g (2.56mmol) of 2-mercaptoethanol to 750ml of methyl cellosolve. Then, 0.5g of hydrindantin and, then, 20g of ninhydrin are added and dissolved by stirring. A buffer solution (pH 5.51) which is 4M sodium acetate prepared separately is added by 250ml is added to and mixed with the first-mentioned solution. The admixture is then preserved in a closed vessel. The thus prepared ninhydrin reagent can be stably preserved for more than 8 months at 20-30 deg.C. The process explained above is to prepare the reagent in the form of a single solution. The solution, however, may be formed separately in the form of two solutions. By so doing, it is possible to attain higher stability of the reagent. |
