The Research Of Analytical Methods On The Determination Of Impurities In High Purity Tin And Tellurium By ICP-MS

High purity tin, tellurium as well as their compounds and alloys, mainly used for preparing materials including photoelectricity, thermoelectricity, catalysts, electronic solders, electrode, gas sensitivity, probe, and special glass, are widely used in industries, such as the new energy, chemical, semiconductor, aerospace, defense industry, and optical equipment, etc. Sustainable progress has been rapid in the area of the cutting-edge technology as high purity tin and tellurium expand their ranges of applications. It is necessary to strictly control the content of impurity elements in high purity tin and tellurium which will affect the performance of many subsequent products. It is of great significance to accurately measure the content of impurity elements in high purity tin and tellurium which determines the quality and price.In recent decades, the measurement of the content of impurity elements in high purity tin and tellurium has changed from lengthy and cumbersome chemical analysis into modern instruments methods with more convenience in current faster operation, more accuracy and reliance in data analysis as well as a broader scope of measured elements. It is always a project for researchers who analyze high purity tin and tellurium to find ways to reduce matrix interference and a more appropriate analytical instrument due to the important influence of the selection of apparatus and pre-processing methods on the accuracy of the measurement of the content of impurity elements in high purity tin and tellurium. But throughout all the previous analytical methods, most of them show the following deficiencies:the matrix of tin and tellurium interferes the measurement of the content of impurity elements; there’s a great pollution on the environment and the instrument; the performance of the instrument cannot reach detecting requirements. Aiming at all those problems above, the article, combined with studies of former researchers and the nature of high purity tin and tellurium, separates the matrix of high purity tin through bromide volatile to measure its16impurity elements and the matrix of high purity tellurium through vacuum distillation to measure its9impurity elements. In the optimal choice of instruments, an inductively coupled ICP-MS with good stability, high sensitivity, low detection limit, wide linear range, strong anti-interference capability, simultaneous multi-element measurement has been chosen to complete the following main work and the conclusions are as follows.The article separates the matrix of high purity tin through bromide volatilization and the matrix of high purity tellurium through vacuum distillation, taking physical and chemical properties of high purity tin and tellurium as well as related literature into consideration. The author chooses to separate the matrix of tin through bromide, because high purity tin has a low halide boiling point and a higher vapor pressure, separating and volatilizing through the easier volatile SnBr4and SnCl4. During the matrix separation of high purity tellurium, make use of the differences between the volatile speed and vapor pressure of impurity elements in tellurium and those of the tellurium matrix under the heating process in vacuum to separate impurity elements and the tellurium matrix in volatilization or condensation. The experiment has proved that the separation of the matrix of high purity tin through bromide volatilization and that of the matrix of high purity tellurium through vacuum distillation effectively eliminates the interference of impurity elements, and reduces the contamination of instruments sample introduction system.In order to find the optimal conditions for matrix separations, the article has done a series of experiments. In the experiment on conditions for the matrix separation of high purity tin, the summarization has been made about the optimal volatile temperature, amount of reagents, and residual rate of the matrix. The experiment shows that90～100℃is the optimal volatile temperature of high purity tin; when the weight of water quenching samples is1.0000g, it reaches the optimal effect of sample dissolution with8～15mL HCl and4～7mL H2O2;6.0mL is the most appropriate volume of HBr to be used in bromide volatilization. In the experiment on conditions for the matrix removal of high purity tellurium, there are conclusions about the optimal temperature and time of distillation, which has been found at450℃and3to5hours respectively.In order to obtain the optimal test results, the article selects107Ag、27Al、209Bi、111Cd、59Co、52Cr、63Cu、56Fe、115In、24Mg、55Mn、23Na、60Ni、208Pb、126Te、64Zn as the measured isotopes of the impurity elements in high purity tin and107Ag、27Al、59Co、52Cr、63Cu、56Fe、55Mn、60Ni、48Ti as the measured isotopes of the impurity elements in high purity tellurium based on the principles of high sensitivity, large abundance, and little interference. Optimize the instruments before testing the samples, ignite the plasma step by step, and tune the instruments after stabilizing10minutes or more. Tune the solution after the Inhalation of Li, Be, Mg, Fe, In, Ce, Pb, and U with the concentration of1ng/mL, optimize it after stabilization, and then check the results when the analysis completes. If the results meet the requirements, then the tuning part can be finished and start the sample tests in standard mode. It is more appropriate to choose collision mode to measure56Fe because of the interference from polyatomic ions such as40Ar16O,38Ar18O,38Ar17O1H and40Ar15N1H with56Fe. There’s less interference with other elements, so the measurement of standard mode meets the requirements quite well. The mixed standard solution of the selected impurity elements in high purity tin and high purity tellurium is0,5,20,100,400ng/mL.Under the selected experimental conditions, the blank value of high purity tin reagent lies between2-23ng/g with the detection limit between3-21ng/g. The relative standard deviation (RSD) of impurity elements in5N and4N high purity tin is3.0～12.7%and3.3～11.3%respectively with the recoveries of90.0%～102.3%and92.0%～103.5%respectively. The blank value of high purity tellurium reagent lies between2-18ng/g with the detection limit between5～19ng/g. The relative standard deviation (RSD) of impurity elements in6N,5N and4N high purity tellurium is5.5～17.1%,4.0～10.9%, and3.5～9.1%respectively with the recoveries of90.0%～103.0%,90.0%～102.8%, and90.3%～102.0%respectively. The experimental results indicate that measuring the impurity elements in high purity tin through bromide volatilization and the impurity elements in high purity tellurium through vacuum distillation is better in precision and higher in recoveries in well conformity with the testing demands of high purity tin and tellurium batch samples. The two innovative methods to some extent provide a useful reference for the measurement of impurity elements in high purity tin and tellurium.