CAJ | 학술논문

基于3.2×10~(-4) mol/LH_2SO_4介质中,痕量硒(Ⅳ)催化KIO_4氧化中性红的褪色反应,建立了测定痕量硒(Ⅳ)的动力学光度法.在固定加热时间段(6 min)后,于530 nm处测定中性红的吸光度降低值监控反应速率.方法检出限为0.36 μg/L,校准曲线的质量浓度线性范围为0～8.0 μg/L.实验了酸度、反应物浓度、温度、反应时间、干扰离子等因素的影响.研究了反应的最佳条件,并测定了一些动力学参数,催化反应的表观活化能为81.60 kJ/mol.11次重复测定0.1 μg/25 mL和0.2 μg/25 mL Se(Ⅳ)的相对标准偏差分别为2.1%和1.9%.方法用于食品和人发样品中痕量硒(Ⅳ)的测定,相对标准偏差为0.33%～3.8%,加标回收率为96.0%～103.0%.
기우3.2×10~(-4) mol/LH_2SO_4개질중,흔량서(Ⅳ)최화KIO_4양화중성홍적퇴색반응,건립료측정흔량서(Ⅳ)적동역학광도법.재고정가열시간단(6 min)후,우530 nm처측정중성홍적흡광도강저치감공반응속솔.방법검출한위0.36 μg/L,교준곡선적질량농도선성범위위0～8.0 μg/L.실험료산도、반응물농도、온도、반응시간、간우리자등인소적영향.연구료반응적최가조건,병측정료일사동역학삼수,최화반응적표관활화능위81.60 kJ/mol.11차중복측정0.1 μg/25 mL화0.2 μg/25 mL Se(Ⅳ)적상대표준편차분별위2.1%화1.9%.방법용우식품화인발양품중흔량서(Ⅳ)적측정,상대표준편차위0.33%～3.8%,가표회수솔위96.0%～103.0%.
Based on the oxidation of neutral red by KIO_4 in 3.2×10~(-4) mol/L sulfuric acid solution, a simple kinetic spectrophotometric method was developed for the determination of trace amounts of Se(Ⅳ). The reaction was monitored spectrophotometrically by measuring the decrease in the absorbance of neutral red at 530 nm with a fixed-time method. The decrease in the absorbance of neutral red is proportional to the concentration of Se(Ⅳ) in the range 0～8.0 μg/L with a fixed time of 4～6 min from the initiation of the reaction. The limit of detection is 0.36 μg/L Se(Ⅳ). The influence of the factors such as acidity, concentration of reactants, reaction time, temperature and co-existing ions on the reaction is discussed. The optimum conditions of reaction are established and some kinetic parameters are determined. The apparent activation energy of catalytic reaction is 81.60 kJ/mol. The relative standard deviations for the determination of 0.1 and 0.2 μg/25 mL Se(Ⅳ) were 2.1 and 1.9%, respectively. The method has been successfully applied to the determination of Se(Ⅳ) in foodstuff and human hair samples with the relative standard deviations of 0.33%～3.8% and the recoveries of 96.0%～103.0%.