连续流动-水杨酸盐分光光度法测定葡萄酒及 葡萄汁中氨氮含量

Determination of ammonium nitrogen in wines and grape juice using continuous flow analysis (CFA) and salicylate spectrophotometry

中文关键词:  连续流动分析仪  葡萄酒  葡萄汁  氨氮

英文关键词:continuous flow analysis  wines  grape juice  ammonia nitrogen

中文摘要:

      目的 利用连续流动分析仪建立以水杨酸-次氯酸盐比色法为基础的葡萄酒和葡萄汁中氨氮的分析方法。方法 葡萄汁及葡萄酒样品经过滤后直接进样, 试样与试剂在蠕动泵的推动下进入化学反应模块, 在密闭的管路中连续流动, 并按特定的顺序和比例混合、反应, 显色完全后进入流动检测池进行光度检测。结果 氨氮标准溶液利用12%乙醇溶液配制线性范围为0~60 mg/L, 相关系数(r2)大于0.999; 方法检出限(LOD)为0.015 mg/L。在低、中、高三个浓度水平添加下, 样品氨氮回收率范围为90.0%~96.8%, 相对标准偏差(n=6)均小于1%。结论 该方法灵敏度高, 重复性好, 操作简便, 适用于大批量葡萄酒和葡萄汁中氨氮含量的检测。

英文摘要:

      Objective To establish a method for the determination of ammonium nitrogen in wines and grape juice by continuous flow analysis (CFA) and salicylate spectrophotometry. Methods The automatic dosage of wines and grape juice were introduced into a flow system (manifold) in which the samples mixed, reacted with the reagent solutions on their way through the manifold by pump. The reaction product was measured in a flow detector. Results The perfect linearity (r2>0.999) of ammonium nitrogen standards, which were prepared with 12% ethnol-water, was achieved within the ranges of 0~60 mg/L. The detection limit of the method was 0.015 mg/L. The recoveries of ammonium at 3 different spiked levels (low, medium, high) were within range from 90.0% to 96.8% and the relative standard deviations (RSDs, n=6) were below 1%. Conclusion This method is efficient, sensitive, reproducible, and reliable, and suitable for the determination of ammonia nitrogen in large number of samples of wines and grape juice.