快速蒸馏-自动pH电位滴定法测定挥发性盐基氮  

Determination of TVB-N by rapid distillation and auto pH potentiometric titration method

作　　者：陈翔[1] 倪蓉[1] 张燕[1] 刘兰侠[1] 

机构地区：[1]上海市徐汇区疾病预防控制中心,上海200237

出　　处：《中国卫生检验杂志》2014年第3期333-334,340,共3页Chinese Journal of Health Laboratory Technology

摘　　要：目的建立快速蒸馏-自动pH电位滴定法测定挥发性盐基氮的方法。方法采用浸渍和过滤的方法预处理样品，使用半自动蒸馏仪快速蒸馏样品滤液，以不加指示剂的硼酸吸收馏出液，使用滴定仪自动完成样品馏出液的pH电位滴定。结果挥发性盐基氮样品滤液的最佳蒸馏时间为3min，pH电位滴定的终点pH值为5．2，5种肉类样品测定的相对标准偏差（RSD）为1．4％-4．0％（n=7），不同挥发性盐基氮含量的肉类样品测定的平均回收率为99．5％，对9种肉类样品使用本法及国标法分别测定，结果显示两法差异无统计学意义。结论快速蒸馏-自动pH电位滴定法测定挥发性盐基氮具有简单、快速，准确的特点，该法还无需加入指示剂，和国标法相比较具有明显优势，该法适用于各种肉类及肉制品中挥发性盐基氮含量的测定。Objective To establish a rapid distillation and auto pH potentiometric titration method to determine TVB - N in meat and meat products. Methods The samples were pretreated by dipping and filtrating, then the filtrate of sample was dis- tilled rapidly with semi - automatic distillation apparatus and dissolved in boric acid absorption solution without adding any chemical indicator. The pH potentiometrie titration of the absorption was completed by automatic titrator. Results The optimal time of TVB - N sample distillation was 3 minutes. The pH endpoint of potentiometric titration was 5.2. The relative standard deviation was between 1.4% and 4.0% （ n =7） for 5 kinds of meat. The average recovery rate of TVB - N was 99.5%. There was no significant difference between the results determined by this method and that of the national standard method. Conclu- sion The rapid distillation and auto pH potentiometric titration method was simple and rapid with good accuracy. Compared with the national standard method, non - adding chemical indicator was an obvious advantage of this method. This method was suitable for determination of TVB - N in all kinds of meat and meat nroducts.

关 键 词：蒸馏 电位滴定法 挥发性盐基氮 

分 类 号：O657.15[理学—分析化学]