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
Flow injection biamperometry was extended to irreversible couple systems. For the biamperometry, the essential condition is the coexistence of two reactants, with opposite electrode reaction, of two independent and ir...Flow injection biamperometry was extended to irreversible couple systems. For the biamperometry, the essential condition is the coexistence of two reactants, with opposite electrode reaction, of two independent and irreversible couples in the same system. The system can be skillfully constructed with analyte by choosing such a reactant of one couple as its standard redox potential which was better closed to that of the analyte as nearly as possible. In the chosen system, provided the real potentials of the two working electrodes have exceeded the deposition potential of two reactants by imposing a suitable potential difference Δ E between these two electrodes, faradic current i will flow through circuit. When the concentration of the chosen reactant remains larger constant, the circuit current i will be linearly proportional to the analyte of interest over certain concentration range. To verify the feasibility of the biamperometry, three systems of the dissolved oxygen separately with ascorbic acid, hydrazine chloride and hydroxyamine chloride were examed. In phosphate buffer(pH 6.9) solution containing the dissolved oxygen, using two activated platinum wire working electrodes imposed by potential difference Δ E 0 0 V, the circuit current i was linearly proportional to these three analytes in the concentration range of 1×10 -5 —1×10 -3 mol/L for ascorbic acid, 1×10 -6 —1×10 -4 mol/L for hydrazine chloride and hydroxyamine chloride, respectively. [WT5HZ]展开更多
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Flow injection biamperometry was extended to irreversible couple systems. For the biamperometry, the essential condition is the coexistence of two reactants, with opposite electrode reaction, of two independent and irreversible couples in the same system. The system can be skillfully constructed with analyte by choosing such a reactant of one couple as its standard redox potential which was better closed to that of the analyte as nearly as possible. In the chosen system, provided the real potentials of the two working electrodes have exceeded the deposition potential of two reactants by imposing a suitable potential difference Δ E between these two electrodes, faradic current i will flow through circuit. When the concentration of the chosen reactant remains larger constant, the circuit current i will be linearly proportional to the analyte of interest over certain concentration range. To verify the feasibility of the biamperometry, three systems of the dissolved oxygen separately with ascorbic acid, hydrazine chloride and hydroxyamine chloride were examed. In phosphate buffer(pH 6.9) solution containing the dissolved oxygen, using two activated platinum wire working electrodes imposed by potential difference Δ E 0 0 V, the circuit current i was linearly proportional to these three analytes in the concentration range of 1×10 -5 —1×10 -3 mol/L for ascorbic acid, 1×10 -6 —1×10 -4 mol/L for hydrazine chloride and hydroxyamine chloride, respectively. [WT5HZ]
