摘要
建立了一种测定抗坏血酸的方便、快捷、高灵敏度的催化动力学光度法。对氨基苯磺酸与亚硝酸根进行重氮化反应生成重氮盐 ,抗坏血酸对重氮盐的分解有催化作用。利用加入8_羟基喹啉与该重氮盐反应生成偶氮染料来终止反应。在波长495nm处 ,用1cm比色皿以水作参比测定其吸光度 ,最佳测定酸度为pH9.0。吸光度与空白体系的差值ΔA与抗坏血酸的质量浓度呈线性关系。该法测定抗坏血酸的线性范围为0.16～6.3mg/L,检出限为0.005mg/L。利用该法测定了维生素C片剂及荔枝晶中的抗坏血酸含量 ,并与碘量法进行对照 。
A simple, rapid and sensitive catalytic kinetic spectrophotometric method for the determination of ascorbic acid was proposed. The diazo _ salt can be produced by the diazotized reaction between p _ amino _ benzenesulfonic acid and nitrite. Ascorbic acid catalyzes the decomposition of the diazo _ salt. The catalytic reaction rate is related to the concentration of ascorbic acid. Oxine was added into solution to end the reaction by coupling with the diazo _ salt and producing azo _ dye. The absorbancy(A) of the system and blank was detected at 495 nm in NH3-NH4Cl buffer solution of pH 9. The linear relationship between ΔA and concentration of ascorbic acid was found in the range of 0.16～6.3 mg/L, and detection limit is 0.005 mg/L. The method was used to determine ascorbic acid in vitamin C tablets and litchi powder. The experimental results agreed with those obtained by iodimetry.
出处
《分析测试学报》
CAS
CSCD
北大核心
2001年第4期26-29,共4页
Journal of Instrumental Analysis
