| In this paper, the main aim is to study the analysis of inorganic elements in complex matrix samples. By study of sample pretreatment, an appropriate pretreatment method was established. The metal elements in matrix sample—iodixanol injection were measured by inductively coupled plasma atomic emission spectrometry(ICP-AES) and inductively coupled plasma mass spectrometry(ICP-MS), respectively. Established a rapid and clean method of sample preparation on separation of the components in phosphate samples, determination of trace copper in the sample with inductively coupled plasma mass spectrometry(ICP-MS) and the graphite furnace atomic absorption spectrometry(AAS-GF).Explored 7 kinds of sample pretreatment methods for iodixanol injection, but the solution will be precipitation in the end, in order to ensure the accuracy of the results, all of the pretreatment methods cannot be used. Considering the nature of the sample and the tolerance ability of organic solvent of the instrument, eventually choose the direct dilution method for determinate. The method is fast, low pollution and low cost.Samples should be diluted 20 times for determination As, Pb, Cd, Sb with ICP-MS, the linear correlation coefficient of each element were greater than 0.999;detection limit were 0.18 ng/ml, 0.43 ng/ml, 0.072 ng/ml, 0.006 ng/ml, respectively; standard addition recovery rate were close to 100%; the precision is good. Diluted the samples 10 times for determinate Al、Si、B with ICP-AES, the linear correlation coefficient of each element were greater than 0.999; detection limit were 0.049μg/ml、0.0381μg/ml、0.0219μg/ml, respectively; standard addition recovery rate were close to 100%; the precision is good.With the use of high pure HF and HNO3 reagents, and autoclaves made of high purity PFA material, a solution sample digestion technique effective for phosphate samples,subjected to high temperature fusion,was established, the whole procedure was concise, fast and of low blank value. Key factors such as the amount and ratios of the reagents, the digestion temperature and time, were systematically optimized, it was found that only 1.7 ml of total reagent consumption could lead to a complete sample decomposition within 0.5 which greatly reduced the risk of contamination.In addition, an effective liquid-liquid extraction procedure based on 5-nonylsalicylaldehyde oxime as the extractant was established for matrix separation and analyte preconcentration. Under the optimal extraction conditions of 5 ml of 15% extractant, 0.5% HNO3 of extraction acidity and 20% HNO3 of back-extraction acidity, a matrix separation efficiency of over 99.999% could be realized and a preconctration factor of 10 could be obtained, which resulted in complete elimination of the matrix-induced interference and great enhancement of the analytical sensitivity. After optimization of the operation parameters of ICP-MS, high signal to background detection of Cu in 20%HNO3 at 840 W of plasma power and low sample uptake rate was realized. The detection limits of 2.5 ng/g, RSD of 3.3% for six detections of parallel samples, and the recovery of 94.3% and 97.5% for spike test were obtained. Separate the matrix from the target analyte with the use of ammonium hydroxide. After optimization of the operation parameters of AAS-GF, The ashing temperature is 1300 ℃, heating up time is 30 s, retention time is 40 s. The detection limits of 3.4 ng/g, RSD of 4.2% for six detections of parallel samples, and the recovery of 92.5% and 95.9% for spike test were obtained. And the method was finally applied to three real samples analysis, and the results agreed well with the data from laser adsorption loss experiment. h at 150℃. Most importantly, the samples were not required to be ground to fine powder,... |
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