磷锑钼三元杂多酸光度法测定药品中的抗坏血酸  

SPECTROPHOTOMETRIC DETERMINATION OF ASCORBIC ACID IN PHARMACEUTICALS WITH MOLYBDOANTIMOPHOSPHORUS TERNARY HETEROPOLY ACID

作　　者：陈玉銮[1] 肖景娴[1] 许艳[1] 

机构地区：[1]南京化工大学应用化学系

出　　处：《南京化工大学学报》1996年第3期76-81,共6页Journal of Nanjing University of Chemical Technology(Natural Science Edition)

摘　　要：研究了少量抗坏血酸与磷锑钼三元杂多酸体系的显色特性，建立了借磷锑钼三元杂多蓝测定抗坏血酸的分光光度法。最佳显色条件为［ＰＯ３－４］＝３０×１０－４ｍｏｌ·Ｌ－１，［ＳｂⅢ］＝４５×１０－５ｍｏｌ·Ｌ－１，［ＭｏＯ２－４］＝７５×１０－３ｍｏｌ·Ｌ－１，Ｐ∶Ｓｂ∶Ｍｏ＝１∶０１５∶２５，［Ｈ加入］／［Ｍｏ］＝５７。测定波长为λｍａｘ＝７１０ｎｍ，线性范围为１～５０μｇ·ｍＬ－１，回归方程为Ａ＝３６８０Ｃ－００１４，线性相关系数ｒ＝０９９９８，表现摩尔吸光系数ε７１０＝３６８×１０３Ｌ·ｍｏｌ－１·ｃｍ－１，检出限为０２μｇ·ｍＬ－１，标准回收率为９５％～１００％，变异系数ｃｖ≤０３４％（ｎ＝６）。与二元磷钼杂多酸方法相比，省去了水浴加热的繁琐操作，而且由于锑（Ⅲ）的引入，显色在室温下３５ｍｉｎ便可完成，并可稳定５ｈ。A new method is described for spectrophotometric determination of ascorbic acid based on the reaction of P Sb Mo heteropoly acid with ascorbic acid In suitable acidity, the formed ternary heteropoly acid can be easily reduced to heteropoly blue with a maximum absorption of 710 nm by ascorbic acid at room temperature For the determination of ascorbic acid, optimum conditions are [PO 3- 4]=3 0×10 -4 mol·L -1 ,[MoO 2- 4]=7 5×10 -3 mol·L -1 ,[Sb Ⅲ ]=4 5×10 -5 mol·L -1 and =0 50 mol·L -1 ,respectively Beer′s law is obeyed in the range of 1～50 μg·mL -1 ascorbic acid The apparent molar absorptivity is 3 68×10 -3 L·mol -1 ·cm -1 The linear regression equation is A =3 68×10 3 C 0 014 with a linear correlation coefficient of better than 0 9998 The detection limit of 0 2 μg·mL -1 ,the recovery of 95%～100%,and the coefficient of variation of less than 0 34% (n=6) were estimated, respectively The recommended method is more convenient than that based on the binary molybdophosphoric acid This coloring procedure is completed by only standing at room temperature for 35 minutes,instead of heating and cooling The results obtained by the proposed method shows good agreement with those obtained by the standard method

关 键 词：磷锑钼 三元杂多酸 分光光度法 维生素C 

分 类 号：O657.3[理学—分析化学] TQ466.3[理学—化学]