DIRECT DETERMINATION OF CITRIC ACID IN MILK WITH AN IMPROVED PYRIDINE-ACETIC ANHYDRIDE METHOD
DIRECT DETERMINATION OF CITRIC ACID IN MILK WITH AN IMPROVED PYRIDINE-ACETIC ANHYDRIDE METHOD
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DOI：
10.3168/jds.s0022-0302(58)91152-4
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发表时间：
1958-01-01
影响因子：
3.5
通讯作者：
BOULET, M
中科院分区：
文献类型：
--
作者：
MARIER, JR;BOULET, M
确定了在17 ~ 60 ℃的不同反应温度下测定柠檬酸的最佳反应条件。由此开发的改进方法消除了反应的剧烈性质，即使在高反应温度下也是如此。本文提出了一种在32 ℃反应温度下测定25 ~ 200 μ g柠檬酸的方法，并与以前发表的基于该反应的方法进行了比较;在不需要仔细计时的情况下，获得了更高的灵敏度、稳定性和重现性。经过适当稀释后，可以直接分析牛奶和血清。牛奶的直接分析结果比相应血清的结果高5 - 15%，并被认为代表了牛奶中柠檬酸含量的真实值。
The optimum proportions of pyridine, acetic anhydride, water, and acetic acid, for the determination of citric acid were determined at various reaction temperatures between 17 and 60oC. The modified procedure thus developed eliminates the violent nature of the reaction, even at the high reaction temperatures. A method for the determination of 25 to 200 ug of citric acid, at a reaction temperature of 32oC, is presented and compared with previously published methods based on the reaction; improved sensitivity, stability, ana reproducibility are obtained without careful timing. Milk and serum can be analyzed directly, after suitable dilution. Results of direct analysis of milk were from 5 to 15% higher than those for the corresponding sera and are believed to represent the true values for the citric acid content of milk.