A simple and sensitive flow injection（FI） spectrophotometric method was reported for the determination of uric acid based on the reduction of Fe（III）/ferricyanide in the presence of uric acid. The in situ reduced ...A simple and sensitive flow injection（FI） spectrophotometric method was reported for the determination of uric acid based on the reduction of Fe（III）/ferricyanide in the presence of uric acid. The in situ reduced ions reacted with unreduced portion of ferricyanide/Fe（III） to form soluble Prussian blue, which was monitored at an absorption wavelength of 735 nm. The optimized conditions allow a linear calibration graph in a concentration range of 1―100 μmol/L. The relative standard deviation was in a range of 0.5%―2.5%, with a detection limit（3σ blank） of 0.3 μmol/L and a sampling frequency of 60 injection/h was obtained. The effect of common substances present in human physiological fluids on the determination of uric acid was examined. The method was applied to determining uric acid in human urine samples with the recoveries in a range of 96%―105%. The results agree well with those by spectrophotometric reference method at a confidence level of 95%. Spectrophotometric procedures for uric acid determination in clinical samples were reviewed briefly.展开更多
A flow injection method is proposed for determining vanadium（V）. The method is based on its catalytic effect on the oxidation of malachite green oxalate by bromate. The reaction was monitored spectrophotometrically ...A flow injection method is proposed for determining vanadium（V）. The method is based on its catalytic effect on the oxidation of malachite green oxalate by bromate. The reaction was monitored spectrophotometrically by measuring malachite green oxalate absorbance at λmax = 625 nm. The reagents and manifold variables, which have influences on the sensitivity, were investigated and the optimum conditions were established. The optimized conditions made it possible to determine vanadium in the ranges of 10-140 ng/mL with a detection limit of 5.2 ng/mL and a sample rate of 20 ± 5 samples/h.展开更多
该实验采用乙二胺四乙酸二钠(EDTA-2Na)-磷酸(2 g-5 m L)蒸馏体系对高粱、大曲、酒醅中的氰化物进行蒸馏提取,并结合全自动流动注射分析技术建立了高粱、大曲、酒醅中氰化物的快速测定方法。结果表明,氰化物在5~200μg/L范围内具有良好...该实验采用乙二胺四乙酸二钠(EDTA-2Na)-磷酸(2 g-5 m L)蒸馏体系对高粱、大曲、酒醅中的氰化物进行蒸馏提取,并结合全自动流动注射分析技术建立了高粱、大曲、酒醅中氰化物的快速测定方法。结果表明,氰化物在5~200μg/L范围内具有良好的线性关系(R2=0.999 6),检出限(LOD)为8.10μg/kg,定量限(LOQ)为25.00μg/kg;精密度、重复性、稳定性均良好,相对标准偏差(RSD)均<10%;样品的加标回收率为82.23%~97.64%。该检测技术前处理简便,检测效率较高,定量结果准确可靠,适用于大批量高粱、大曲、酒醅样品中氰化物的检测分析,对于提升白酒的质量安全监测能力具有重要的实际意义。展开更多
A novel chemiluminescence (CL) sensor for the determination of gallic acid combined with flow injection analysis was developed by electrostatically immobilizing luminol and periodate on anion-exchange resins respectiv...A novel chemiluminescence (CL) sensor for the determination of gallic acid combined with flow injection analysis was developed by electrostatically immobilizing luminol and periodate on anion-exchange resins respectively. Gallic acid was sensed by its enhancing effect on the weak CL reaction between luminol and periodate, which were eluted from the ion exchange column. The possible reaction mechanism of the CL system was suggested and discussed. The response of the sensor to gallic acid concentration was linear over the range of 8.0×10 -9-1.0×10 -6 mol/L with a detection limit of 6.5×10 -9 mol/L (3σ). The relative standard deviation (RSD) for 7 repetitive determinations of gallic acid (1.0×10 -7 mol/L) was 1.8%. The sensor could be used for over 400 times determination with a good reproducibility.展开更多
基金Supported by the CIIT-Project Funded by COMSATS Institute of Information Technology,Pakistan
文摘A simple and sensitive flow injection（FI） spectrophotometric method was reported for the determination of uric acid based on the reduction of Fe（III）/ferricyanide in the presence of uric acid. The in situ reduced ions reacted with unreduced portion of ferricyanide/Fe（III） to form soluble Prussian blue, which was monitored at an absorption wavelength of 735 nm. The optimized conditions allow a linear calibration graph in a concentration range of 1―100 μmol/L. The relative standard deviation was in a range of 0.5%―2.5%, with a detection limit（3σ blank） of 0.3 μmol/L and a sampling frequency of 60 injection/h was obtained. The effect of common substances present in human physiological fluids on the determination of uric acid was examined. The method was applied to determining uric acid in human urine samples with the recoveries in a range of 96%―105%. The results agree well with those by spectrophotometric reference method at a confidence level of 95%. Spectrophotometric procedures for uric acid determination in clinical samples were reviewed briefly.
文摘A flow injection method is proposed for determining vanadium（V）. The method is based on its catalytic effect on the oxidation of malachite green oxalate by bromate. The reaction was monitored spectrophotometrically by measuring malachite green oxalate absorbance at λmax = 625 nm. The reagents and manifold variables, which have influences on the sensitivity, were investigated and the optimum conditions were established. The optimized conditions made it possible to determine vanadium in the ranges of 10-140 ng/mL with a detection limit of 5.2 ng/mL and a sample rate of 20 ± 5 samples/h.
文摘该实验采用乙二胺四乙酸二钠(EDTA-2Na)-磷酸(2 g-5 m L)蒸馏体系对高粱、大曲、酒醅中的氰化物进行蒸馏提取,并结合全自动流动注射分析技术建立了高粱、大曲、酒醅中氰化物的快速测定方法。结果表明,氰化物在5~200μg/L范围内具有良好的线性关系(R2=0.999 6),检出限(LOD)为8.10μg/kg,定量限(LOQ)为25.00μg/kg;精密度、重复性、稳定性均良好,相对标准偏差(RSD)均<10%;样品的加标回收率为82.23%~97.64%。该检测技术前处理简便,检测效率较高,定量结果准确可靠,适用于大批量高粱、大曲、酒醅样品中氰化物的检测分析,对于提升白酒的质量安全监测能力具有重要的实际意义。
文摘A novel chemiluminescence (CL) sensor for the determination of gallic acid combined with flow injection analysis was developed by electrostatically immobilizing luminol and periodate on anion-exchange resins respectively. Gallic acid was sensed by its enhancing effect on the weak CL reaction between luminol and periodate, which were eluted from the ion exchange column. The possible reaction mechanism of the CL system was suggested and discussed. The response of the sensor to gallic acid concentration was linear over the range of 8.0×10 -9-1.0×10 -6 mol/L with a detection limit of 6.5×10 -9 mol/L (3σ). The relative standard deviation (RSD) for 7 repetitive determinations of gallic acid (1.0×10 -7 mol/L) was 1.8%. The sensor could be used for over 400 times determination with a good reproducibility.
