Biacetyl反应在双氰胺光度法测定中的应用

介绍了一种简便易行的光度分析方法在双氰胺工业品的含量测定中的应用．该方法根据双乙酰反应（ｂｉａｃｅｔｙｌｒｅａｃｔｉｏｎ）的原理，即：当α－萘酚存在时，含胍基的化合物与双乙酰反应，在强碱性介质中，生成一红色化合物的过程，对双氰胺工业品进行含量测定研究．结果表明，该红色化合物在５３０～５６０ｎｍ处有显著吸收，其摩尔吸光系数ε＝１．６６×１０４Ｌｍｏｌ－１ｃｍ－１，适合于用光度法比色测定．该方法在０～１４ｍｇＬ－１的浓度范围内呈线性关系，符合比耳定律．其测定回收率为９８％～１０１％，相对标准偏差为±０．５９％．此外，该方法还适用于双氰胺残留物的痕量分析和监测．

The Application of Biacetyl Reaction in the Content Determining of Dicyandiamide

A colorimetric method for the content determing of industrial dicyandiamide is introduced in this paper.Its determining basis is on biacetyl reaction(that is ,the reaction of guanidino compound with biacetyl in alkaline solution in the presence of α naphthol).A red compound is produced in the reaction.It has a great absorptivity to the light wave whose wavelength is 530—560nm(molor absorptivity ε=1.66×10 4 Lmol -1 cm -1 ),so it can be determined with colorimetric method.The linear concentration range in accord with Beers Law is 0—14 mgL -1 .The rate of recovery of 98%￣101% can be obtained with this method,and the relative standard deviation is ±0.59%.Besides ,this method can also be used for analysing and monitoring of dicyandiamide residues.