The redox behavior of spironolactone（SP） drug in Britton-Robinson（BR） buffer of pH 2-11 was investigated by differential pulse cathodic stripping voltammetry（DPCSV） and cyclic voltammetry（CV） at hanging mercur...The redox behavior of spironolactone（SP） drug in Britton-Robinson（BR） buffer of pH 2-11 was investigated by differential pulse cathodic stripping voltammetry（DPCSV） and cyclic voltammetry（CV） at hanging mercury dropping electrode（HMDE）.At pH 9-10.5,the DPCSV of SP drug showed two cathodic peaks at1.15 and1.38 V at the HMDE vs.Ag/AgCl reference electrode.In the CV,at pH 9-10,the dependence of the cathodic peak current,Ip,c and peak potential,Ep,c of the second peak（Ep,c2） on the scan rate（n） and on the depolizer（SP） concentrations was typical of an electrode coupled（EC） chemical reaction type mechanism.The plot of Ip,cat 1.380 V of the DPCSV vs.SP concentration at pH 9 was linear over the concentration range of 1.2×1010-9.6×107 M.The lower limit of detection（LLOD） and limit of quantification（LOQ） of the drug were 1.1×1011 and 4.14×1011 M,respectively.The method was successfully applied for the analysis of SP residues in industrial wastewater,in pure form（98.273.1%） and in drug formulations e.g.Aldactones tablet（98.3572.9%）.The method was validated by comparison with HPLC and the official data methods.展开更多
The design principle for a multi-wire proportional chamber with a cathode strip and delay-line readout is described. A prototype chamber of a size of 10 cm×10 cm was made together with the readout electronics cir...The design principle for a multi-wire proportional chamber with a cathode strip and delay-line readout is described. A prototype chamber of a size of 10 cm×10 cm was made together with the readout electronics circuit. A very clean signal with very low background noise was obtained by applying a transformer between the delay-line and the pre-amplifier in order to match the resistance. Along the anode wire direction a position resolution of less than 0.5 mm was achieved with a ^55Fe-5.9 keV X ray source. The simple structure, large effective area and high position resolution allow the application of a gas chamber of this kind to many purposes.展开更多
基金funded by the Deanship of Scientific Research (DSR),King Abdulaziz University under grant number 172/428
文摘The redox behavior of spironolactone（SP） drug in Britton-Robinson（BR） buffer of pH 2-11 was investigated by differential pulse cathodic stripping voltammetry（DPCSV） and cyclic voltammetry（CV） at hanging mercury dropping electrode（HMDE）.At pH 9-10.5,the DPCSV of SP drug showed two cathodic peaks at1.15 and1.38 V at the HMDE vs.Ag/AgCl reference electrode.In the CV,at pH 9-10,the dependence of the cathodic peak current,Ip,c and peak potential,Ep,c of the second peak（Ep,c2） on the scan rate（n） and on the depolizer（SP） concentrations was typical of an electrode coupled（EC） chemical reaction type mechanism.The plot of Ip,cat 1.380 V of the DPCSV vs.SP concentration at pH 9 was linear over the concentration range of 1.2×1010-9.6×107 M.The lower limit of detection（LLOD） and limit of quantification（LOQ） of the drug were 1.1×1011 and 4.14×1011 M,respectively.The method was successfully applied for the analysis of SP residues in industrial wastewater,in pure form（98.273.1%） and in drug formulations e.g.Aldactones tablet（98.3572.9%）.The method was validated by comparison with HPLC and the official data methods.
基金Major State Basic Research Development Program of China (2007CB815002)NSFC (10775003, 10827505)
文摘The design principle for a multi-wire proportional chamber with a cathode strip and delay-line readout is described. A prototype chamber of a size of 10 cm×10 cm was made together with the readout electronics circuit. A very clean signal with very low background noise was obtained by applying a transformer between the delay-line and the pre-amplifier in order to match the resistance. Along the anode wire direction a position resolution of less than 0.5 mm was achieved with a ^55Fe-5.9 keV X ray source. The simple structure, large effective area and high position resolution allow the application of a gas chamber of this kind to many purposes.
