Study On Solid-Phase Extraction-Inductively Coupied Plasma Atomic Emission Spectrometry For Determination Of Chromium,Cadmium,Bismuth,Copper And Manganese In Nickel And Its Compounds

An important means of determining trace impurities in high concentrations of matrix materials was by inductively coupled plasma atomic emission spectrometry (ICP-AES), but the key technical problems in the application field of ICP-AES was how to reduce the determination interference for high concentrations of matrix material. This article reviewed the determination of trace elements in high concentrations of matrix materials and measures to reduce the interference for high concentration of matrix at home and abroad. On this basis, combined with the determination for impurity elements chromium, cadmium, bismuth, copper and manganese in nickel and its compounds by ICP-AES, and studied the properties and the degree of interference for nickel matrix. In order to reduce the determination interference for nickel matrix, we developed a series of methods by solid-phase extraction of impurity element in nickel based on ion exchange fiber. Detail works were as follows:1, The research showed when the mass concentration of nickel was greater than 5800 times of chromium, the nickel had an negative error on the determination of chromium by ICP-AES. This error was greater than 5% and derived from the spectral interference and non-spectral interferences, and the error was amplified with the increment of the nickel concentration. The results showed that the collected effluent did not have nickel in the following conditions:25.0 mL sample solution (pH=1), which contained 5.00×102μg/mL Ni(II) and 1.50 mol/L NH4SCN, was extracted by containing 3.00 g strong base anion exchange fiber of fiber column (0=10 mm) at the flow rate 0.5 mL/min. Because chromium was not absorbed in this condition and collected in the effluent test, which eliminated the interference of nickel matrix on the direct of chromium. And the lower limit of quantification (10s) for chromium was 2.0×10-3μg/mL. Chromium in the actual samples and the synthetic samples were determined, and the results showed that the recovery was in the range of 91.0%～102%, and the relative standard deviation (RSD, n=6) was less than or equal to 3.3%.2, The research showed when the mass concentration of nickel was greater than 1500 times of cadmium and bismuth, the nickel had an negative error on the determination of cadmium and bismuth by ICP-AES. This error was greater than 5% and derived from the spectral interference and non-spectral interferences, and the error was amplified with the increment of the nickel concentration. The results showed that the sample solution which contained 5.00×103 μg/mL Ni(II) and 0.2 mol/L HBr, was extracted by 0.250 g strong base anion exchange fiber for 15 min, then used 0.010 mol/L Na2EDTA solution (pH=5) to eluting load fiber for 20 min. In this case, the residual amount of nickel in elution was much lower than 1500 times of cadmium and bismuth, and did not affect the accurate determination of cadmium and bismuth by ICP-AES. Because Cd(II) and Bi(III) formed complex anion with Br, so there were adsorbed by anion exchange fiber. But Ni(II) could not form complex anion with Br, so it was stayed in the solution. Then based on EDTA was easier formed complex anion with Cd(II) and Bi(III), so the Cd(II) and Bi(III) were eluted from the load fiber, which eliminated the interference of nickel matrix on the determination of cadmium and bismuth. And the lower limit of quantification (10s) for cadmium and bismuth were 2.0×10-3 μg/mL and 1.3×10-2 μg/mL. Cadmium and bismuth in the actual samples and the synthetic samples were determined, and the results showed that the recoveries were in the range of 92.9%-96.0% and 97.1%～103% for cadmium and bismuth, and the relative standard deviations (RSD, n=6) were less than or equal to 3.0% and 3.1% for cadmium and bismuth, respectively.3, The research showed when the mass concentration of nickel was greater than 2000 times of copper, the nickel had an negative error on the determination of copper by ICP-AES. This error was greater than 5% and derived from the spectral interference and non-spectral interferences, and the error was amplified with the increment of the nickel concentration. The results showed that the sample solution (pH=7), which contained 5.00×102μg/mL Ni(Ⅱ) and 0.010 mol/L NaHC4H4O6, the tartaric acid complex anion of Cu2+and Ni2+could be exchanged with a strong base anion exchange fiber. After extracted for 30 min, used deionized water to eluting load fiber which contained Cu(Ⅱ) and Ni(Ⅱ) for 30 min, then Cu(Ⅱ) could to obtain quantitative recovery, and Ni(Ⅱ) could not be eluted. The residual amount of nickel in elution was much lower than 2000 times of copper, and did not have an interference on the accurately determination of copper. And the lower limit of quantification (10s) for copper was 4.2×10-3 μg/mL. Copper in the actual samples and the synthetic samples were determined, and the results showed that the recovery was in the range of 93.7%～103%, and the relative standard deviation (RSD,n=6) was less than or equal to 3.5%.4, The research showed when the mass concentration of nickel was greater than 700 times of manganese, the nickel had an positive error on the determination of manganese by ICP-AES. This error was greater than 5% and mainly derived from the background spectral interference, and the error was amplified with the increment of the nickel concentration. The results showed that the sample solution (pH=4) which contained 5.00×102 μg/mL Ni(Ⅱ) and 0.010 mol/L Na2EDTA, Mn2+ could be exchanged with a H type strong acid cation exchange fiber, because Ni2+ was formed as complex anion with Na2EDTA, so it was stayed in the solution. After extracted for 10 min, used 1.5 mol/L HNO3 to eluting load fiber which contained Mn(Ⅱ) for 10 min, thenMn(II) could to obtain quantitative recovery. The residual amount of nickel in elution was much lower than 700 times of manganese, and did not have an interference on the accurately determination of manganese. And the lower limit of quantification (10s) for manganese was 4.3×10-4μg/mL. Manganese in the actual samples and the synthetic samples were determined, and the results showed that the recovery was in the range of 92.0%～103%, and the relative standard deviation (RSD, n=6) was less than or equal to 1.2%.