A simple and sensitive kinetic spectrophotometric method for the determination of trace amounts of titanium(IV),based upon the catalytic effect of Ti(IV) on the oxidation of acid chrome blue K (ACBK) by hydrogen perox...A simple and sensitive kinetic spectrophotometric method for the determination of trace amounts of titanium(IV),based upon the catalytic effect of Ti(IV) on the oxidation of acid chrome blue K (ACBK) by hydrogen peroxide in 0.002 mol/L sulfuric acid,is described. The reaction rate is monitored spectrophotometrically by measuring the decrease in absorbance of ACBK at 524 nm. The detection limit of the method is 1.01×10?9 g/mL,and the linear range is 0-0.048 mg/L. The influence of acidity,concentration of reactants,reaction time,reaction temperature and for-eign ions is also discussed. The optimum reaction conditions were established and some kinetic parameters determined. The apparent activation energy of the catalytic reaction is 5.32 kJ/mol. The relative standard deviation for the determi-nation of titanium(IV) at the concentration of 0.048 mg/L is calculated to be 1.31% (n = 11). In combination with sol-vent extraction separation,the method has been successfully applied to the determination of trace titanium(IV) in human hair,plant matter,tea and rock samples. The results are in good agreement with the certified values with the relative standard deviations (RSD) of 1.4%-3.5%.展开更多
目的:建立山楂中6个黄酮类物质的液相色谱-串联质谱(LC-MS/MS)测定方法。方法:实验优化了液相色谱条件和质谱参数。采用C_(18)柱分离,流动相为乙腈-水(含0.1%甲酸),梯度洗脱,流速0.2 m L·min^(-1),以电喷雾离子源正离子多反应监测(...目的:建立山楂中6个黄酮类物质的液相色谱-串联质谱(LC-MS/MS)测定方法。方法:实验优化了液相色谱条件和质谱参数。采用C_(18)柱分离,流动相为乙腈-水(含0.1%甲酸),梯度洗脱,流速0.2 m L·min^(-1),以电喷雾离子源正离子多反应监测(MRM)模式进行MS/MS检测。结果:6个黄酮类物质在各自的线性范围内具有良好的线性关系,相关系数大于0.994,低、中、高3个添加水平的平均回收率在80.4%~105.0%之间,RSD小于10%。10批样品中6个黄酮成分的含量测定结果:儿茶素,0.03~5.39μg·g^(-1);牡荆素,0.11~1.02μg·g^(-1);木犀草素,0.02~0.09μg·g^(-1);槲皮素,3.72~14.02μg·g^(-1);芦丁,3.32~5.79μg·g^(-1);金丝桃苷,31.32~80.89μg·g^(-1)。结论:该方法可用于测定山楂中儿茶素、牡荆素、槲皮素、木犀草素、芦丁、金丝桃苷。展开更多
基金Project 0520002 supported by the Natural Science Foundation of Jiangxi Province
文摘A simple and sensitive kinetic spectrophotometric method for the determination of trace amounts of titanium(IV),based upon the catalytic effect of Ti(IV) on the oxidation of acid chrome blue K (ACBK) by hydrogen peroxide in 0.002 mol/L sulfuric acid,is described. The reaction rate is monitored spectrophotometrically by measuring the decrease in absorbance of ACBK at 524 nm. The detection limit of the method is 1.01×10?9 g/mL,and the linear range is 0-0.048 mg/L. The influence of acidity,concentration of reactants,reaction time,reaction temperature and for-eign ions is also discussed. The optimum reaction conditions were established and some kinetic parameters determined. The apparent activation energy of the catalytic reaction is 5.32 kJ/mol. The relative standard deviation for the determi-nation of titanium(IV) at the concentration of 0.048 mg/L is calculated to be 1.31% (n = 11). In combination with sol-vent extraction separation,the method has been successfully applied to the determination of trace titanium(IV) in human hair,plant matter,tea and rock samples. The results are in good agreement with the certified values with the relative standard deviations (RSD) of 1.4%-3.5%.
文摘目的:建立山楂中6个黄酮类物质的液相色谱-串联质谱(LC-MS/MS)测定方法。方法:实验优化了液相色谱条件和质谱参数。采用C_(18)柱分离,流动相为乙腈-水(含0.1%甲酸),梯度洗脱,流速0.2 m L·min^(-1),以电喷雾离子源正离子多反应监测(MRM)模式进行MS/MS检测。结果:6个黄酮类物质在各自的线性范围内具有良好的线性关系,相关系数大于0.994,低、中、高3个添加水平的平均回收率在80.4%~105.0%之间,RSD小于10%。10批样品中6个黄酮成分的含量测定结果:儿茶素,0.03~5.39μg·g^(-1);牡荆素,0.11~1.02μg·g^(-1);木犀草素,0.02~0.09μg·g^(-1);槲皮素,3.72~14.02μg·g^(-1);芦丁,3.32~5.79μg·g^(-1);金丝桃苷,31.32~80.89μg·g^(-1)。结论:该方法可用于测定山楂中儿茶素、牡荆素、槲皮素、木犀草素、芦丁、金丝桃苷。
