A method is described for the direct determination of iron in high purity sodium fluoride using graphite furnace atomic absorption spectrometry. Interferences caused by the matrix are investigated. It is shown that th...A method is described for the direct determination of iron in high purity sodium fluoride using graphite furnace atomic absorption spectrometry. Interferences caused by the matrix are investigated. It is shown that the ashing temperature can be increased to 1 400°C and matrix interferences eliminated, the sensitivity of iron increased in 1. 27 fold by the addition of nickel nitrate. The method is applied to the determination of iron in sodium fluoride and satisfactory results are obtained.展开更多
An alternative spectrophotometric method has been developed for total iron determination using flow injection analysis (FIA). The procedure is based on the coordination reaction between hydralazine and Fe2+ ions, whic...An alternative spectrophotometric method has been developed for total iron determination using flow injection analysis (FIA). The procedure is based on the coordination reaction between hydralazine and Fe2+ ions, which results in the formation of a purple complex monitored at 538 nm. For determination of total iron, Fe3+ ions were reduced using ascorbic acid. Under optimized conditions, a linear calibration graph (0.1 - 6.0 ?g?ml–1;n = 6) was obtained. The method allows LOD (3? of blank/slope = 0.06 ?g?ml–1) and LOQ (10? of blank/slope = 0.22 ?g?ml–1). The RSD ((s/ ) × 100) for a mixed standard containing 0.60 ?g?ml–1 Fe2+ and Fe3+ was 0.10% (n = 10). Recoveries of spiked samples were 94.3% - 106.0%. The analytical frequency was 60 h–1. The effect of possible interferences has been studied. The procedure was successfully applied for analysis of environmental samples. The real samples results were comparable with those obtained by the official method considering a paired t-test and 95% of confidence level.展开更多
The effects of matrix silicate and experimental conditions on the determination of iron in flame atomic absorption spectrometry （FAAS） were investigated. It was found that boric acid as a matrix modifier obviously e...The effects of matrix silicate and experimental conditions on the determination of iron in flame atomic absorption spectrometry （FAAS） were investigated. It was found that boric acid as a matrix modifier obviously eliminated silicate interference. Under the optimum operating conditions, the determination results of iron in layered crystal sodium disilicate and sodium silicate samples by FAAS were satisfactory. The linear range of calibration curve is 0-10.5 μg.mL^-1, the relative standard deviation of method is 1.2%-2.2%, the recovery of added iron is 96.0%- 101%, the sensitivity is 0.19 μg.mL^-l and the detection limit is 77 ng.mL^-1. The effect of the determination of iron of the standard curve method, standard addition calibration and colorimetry method was the same, but the first has the merits of rapid sample preparation, reduced contamination risks and fast analysis.展开更多
文摘A method is described for the direct determination of iron in high purity sodium fluoride using graphite furnace atomic absorption spectrometry. Interferences caused by the matrix are investigated. It is shown that the ashing temperature can be increased to 1 400°C and matrix interferences eliminated, the sensitivity of iron increased in 1. 27 fold by the addition of nickel nitrate. The method is applied to the determination of iron in sodium fluoride and satisfactory results are obtained.
基金Financial support from CNPq,CNPq/CTHIDRO,CAPES and FAPEAL(Brazil)
文摘An alternative spectrophotometric method has been developed for total iron determination using flow injection analysis (FIA). The procedure is based on the coordination reaction between hydralazine and Fe2+ ions, which results in the formation of a purple complex monitored at 538 nm. For determination of total iron, Fe3+ ions were reduced using ascorbic acid. Under optimized conditions, a linear calibration graph (0.1 - 6.0 ?g?ml–1;n = 6) was obtained. The method allows LOD (3? of blank/slope = 0.06 ?g?ml–1) and LOQ (10? of blank/slope = 0.22 ?g?ml–1). The RSD ((s/ ) × 100) for a mixed standard containing 0.60 ?g?ml–1 Fe2+ and Fe3+ was 0.10% (n = 10). Recoveries of spiked samples were 94.3% - 106.0%. The analytical frequency was 60 h–1. The effect of possible interferences has been studied. The procedure was successfully applied for analysis of environmental samples. The real samples results were comparable with those obtained by the official method considering a paired t-test and 95% of confidence level.
文摘The effects of matrix silicate and experimental conditions on the determination of iron in flame atomic absorption spectrometry （FAAS） were investigated. It was found that boric acid as a matrix modifier obviously eliminated silicate interference. Under the optimum operating conditions, the determination results of iron in layered crystal sodium disilicate and sodium silicate samples by FAAS were satisfactory. The linear range of calibration curve is 0-10.5 μg.mL^-1, the relative standard deviation of method is 1.2%-2.2%, the recovery of added iron is 96.0%- 101%, the sensitivity is 0.19 μg.mL^-l and the detection limit is 77 ng.mL^-1. The effect of the determination of iron of the standard curve method, standard addition calibration and colorimetry method was the same, but the first has the merits of rapid sample preparation, reduced contamination risks and fast analysis.
