基于三元络合反应的高粱中单宁测定新方法

基于铁（Ⅲ）可与硫氰酸根离子和单宁发生络合反应生成稳定的三元离子络合物的性质,建立了分光光度法测定高粱中单宁的新方法。结果表明,显色剂与单宁反应后溶液颜色变化显著,在575nm处有明显的吸收峰;在优化后的条件下,单宁浓度在0.001⁰.06g/L范围内服从朗伯-比耳定律,回归方程为Y=13.664X+0.0389,相关系数R2=0.9993。该方法的平均回收率在95.77%¹01.60%范围内,RSD<1%。以此方法应用于高粱样品中单宁酸含量的测定,与国标检测方法（GBT 15686-2008）结果一致。该方法简便快捷,灵敏度高,特异性好,抗干扰性能力强,测定的结果准确,可应用于高粱中单宁的检测。 

Establishment of a new determination method of tannin in sorghum grain based on ternary complex reaction

Based on the property of Fe (Ⅲ) with thiocyanate and tannin can occur specific reaction to form a stable three element metal ionic compounds, a new method for the determination of tannin in sorghum grain sorghum was established. The results showed that the color of liquid changed significantly after the reaction of ferric thiocyanate and tannin, and there was an obvious absorption peak at 575nm. Under the optimized conditions, the concentration of tannins between 0. 001 ⁰. 06g / L was obeyed the Lambert-Beer ' s law. Correspondingly, the regression equation was Y=13.664X+0.0389, and the correlation coefficient R2was 0.9993. The average recovery of this new method was in the range of 95.77%¹01.60%, and the RSD<1%. This new method was used to determined tannins content in sorghum samples, and the results were consisted with national standard test method (GBT 15686-2008) . The method, which is simple, rapid, high sensitivity, specificity and strong anti-interference ability, can be applied to the sorghum tannins rapid detection and identification of sorghum varieties.