This paper presents a new method of determining Ge in AuGe alloys by potassium iodate(KIO3)potentiometric titration when Ge(Ⅱ)and Au(0)are simultaneously reduced from Ge(Ⅳ)and Au(Ⅲ)by sodium hypophosphite rather th...This paper presents a new method of determining Ge in AuGe alloys by potassium iodate(KIO3)potentiometric titration when Ge(Ⅱ)and Au(0)are simultaneously reduced from Ge(Ⅳ)and Au(Ⅲ)by sodium hypophosphite rather than by distillation separation.The influences of such conditions as the reduction acidity,the dosage of sodium hypophosphite and the reduction time on the determination of Ge were studied.Ge in AuGe alloys such as AuGe_(12),AuGeNi_(12-2),AuAgGe_(18.8-12.5),and AuAgGeNi_(43.8-6-0.2)was measured with the relative standard deviation(RSD)of 0.10%-0.31%and the recoveries of added standard Ge in sample of 99.40%-100.40%under the conditions of 0.40-0.80 mol·L^(-1)HCl,3.3 mol·L^(-1)H^(3)PO^(4),15 g sodium hypophosphite,and reduction time of40 min.The new method presented is of high accuracy in results,good stability and sensibility in end-point,and easy operation and strong selectivity of determination.展开更多
This study determined concentrations of iodine, consistent with WHO iodine fortification standards, in commercial edible salts mostly consumed in Harper. The following hypothesis was put forward in the research study;...This study determined concentrations of iodine, consistent with WHO iodine fortification standards, in commercial edible salts mostly consumed in Harper. The following hypothesis was put forward in the research study;H<sub>1</sub>: the iodine content of the two brands of iodized salts is different from the WHO iodine fortification levels;H<sub>0</sub>: the iodine content of the two brands of iodized salts is not different from the WHO iodine fortification levels. The hypothesis was tested in MS Excel 2010 and 2016 via the T-Test function giving p-value = 0.1476 and p-value = 0.0395 indicative of no significant difference in the iodine concentration of the salts compared with the lower limit of WHO standard 20 mg·Kg<sup>-1</sup> and huge contrast in the iodine concentration of the salts compared with the upper limit of WHO standard 40 mg·Kg<sup>-1</sup> respectively. The UV spectrophotometric method was used to analyze and measure the iodine concentration in the twelve (12) samples of two different brands bought from grocery stores in Harper city. Results indicated that all samples of the two (2) brands of iodized salts contained iodine of no significant difference relative to the lower limit of WHO standard but far below the upper limit of the WHO standard. The study therefore recommends monitoring of commercial iodized salts by appropriate authorities in Harper to ascertain the WHO iodization fortification standards before reaching consumers.展开更多
基金the National High Technology Research and Development Program of China (Nos.2012AA063203 and 2012AA063207)。
文摘This paper presents a new method of determining Ge in AuGe alloys by potassium iodate(KIO3)potentiometric titration when Ge(Ⅱ)and Au(0)are simultaneously reduced from Ge(Ⅳ)and Au(Ⅲ)by sodium hypophosphite rather than by distillation separation.The influences of such conditions as the reduction acidity,the dosage of sodium hypophosphite and the reduction time on the determination of Ge were studied.Ge in AuGe alloys such as AuGe_(12),AuGeNi_(12-2),AuAgGe_(18.8-12.5),and AuAgGeNi_(43.8-6-0.2)was measured with the relative standard deviation(RSD)of 0.10%-0.31%and the recoveries of added standard Ge in sample of 99.40%-100.40%under the conditions of 0.40-0.80 mol·L^(-1)HCl,3.3 mol·L^(-1)H^(3)PO^(4),15 g sodium hypophosphite,and reduction time of40 min.The new method presented is of high accuracy in results,good stability and sensibility in end-point,and easy operation and strong selectivity of determination.
文摘This study determined concentrations of iodine, consistent with WHO iodine fortification standards, in commercial edible salts mostly consumed in Harper. The following hypothesis was put forward in the research study;H<sub>1</sub>: the iodine content of the two brands of iodized salts is different from the WHO iodine fortification levels;H<sub>0</sub>: the iodine content of the two brands of iodized salts is not different from the WHO iodine fortification levels. The hypothesis was tested in MS Excel 2010 and 2016 via the T-Test function giving p-value = 0.1476 and p-value = 0.0395 indicative of no significant difference in the iodine concentration of the salts compared with the lower limit of WHO standard 20 mg·Kg<sup>-1</sup> and huge contrast in the iodine concentration of the salts compared with the upper limit of WHO standard 40 mg·Kg<sup>-1</sup> respectively. The UV spectrophotometric method was used to analyze and measure the iodine concentration in the twelve (12) samples of two different brands bought from grocery stores in Harper city. Results indicated that all samples of the two (2) brands of iodized salts contained iodine of no significant difference relative to the lower limit of WHO standard but far below the upper limit of the WHO standard. The study therefore recommends monitoring of commercial iodized salts by appropriate authorities in Harper to ascertain the WHO iodization fortification standards before reaching consumers.