挥发性盐基氮的光谱分析方法

报道了一种挥发性盐基氮(TVB-N)测定方法。通过奈斯勒试剂处理的分子筛吸收挥发性盐基氮，形成NH₂Hg₂IO固相显色体，采用漫反射光谱装置直接测定。探讨了测量原理、条件及影响因素，表明该方法具有操作方便，灵敏度高，试剂用量少等优点。方法的线性范围为1～8 μg·mL-1,检测限达0.1 g·mL-1。用于鱼、肉食品新鲜度的监测，发现鱼肉随放置时间的延长，挥发性盐基氮迅速增加，表明鱼肉的腐败变质是一个加速过程，并且鱼的变质速率相对猪肉更快一些。

A Spectral Analysis Method for Total Volatile Base Nitrogen

A new method for the determination of the total volatile basic nitrogen (TVB-N) by reflectance spectroscopy was developed. The method was based on the reaction of TVB-N with Nessler’s reagent treated by molecular sieve and the reflectance-absorption value F(R), which is directly proportional to the amount of NH2Hg2IO in solid phase, was measured by the reflection spectrometer. The fundamental principle, effective factors and experimental conditions of the method were discussed. The special features of this method were its simplicity in operation, relatively high sensitivity of determination and the use of a small amount of reagent. Linear calibration graph was obtained in the range 1-8 μg·mL-1 with a detection limit of 0.1 μg·mL-1. The method was applied to monitor the fresh degree of fish and pork. The result discovered that the total volatile basic nitrogen increased rapidly along with the time extension, indicating that the deterioration of fish and pork was an acceleration process, and the deterioration speed of fish was faster than that of pork.