光度法快速测定长链二元酸的含量

Rapid Photometric Determination of Long Chain Dicarboxylic Acids

长链二元酸与硫酸铜甲醇溶液反应生成沉淀,离心去除沉淀后,于波长820 nm处测定上清液吸光度,提出了光度法间接测定长链二元酸含量的方法。长链二元酸的质量浓度在5～40 g·L^(-1)范围内与吸光度呈线性关系,方法检出限(3s/k)为0.011 g·L^(-1)。方法的回收率在104%～105%之间,测定值的相对标准偏差(n=5)小于0.6%。

Long chain dicarboxylic acids reacted with Cu2＋ in methanol solution of CuSO4 to form a precipitate. After centrifugation, absorbance of the supernatant was determined at 820 nm. Based on this fact, a photometric method for indirect determination of long chain dicarboxylic acids was proposed. Linear relationship between values of absorbance and mass concentration of long chain dicarboxylic acids was kept in the range of 5- 40 g · L-1, with detection limit （3s/k） of 0. 011 g · L-1. Values of recovery were found in the range of 104%- 105%, and RSD＇s （n=5） were less than 0. 6%.