Sample preparation method for uniformly distributing trace components in solid block matrix

Abstract

The invention discloses a sample preparation method for uniformly distributing trace components in a solid block matrix. The method comprises the following steps: (1) sequentially drying, grinding and screening trace components to be measured; (2) accurately weighing a certain amount of trace components and a plastic matrix according to the formula design, heating to a melting temperature so as to melt the plastic matrix, adding the trace components into the melted plastic matrix under stirring condition, stirring and mixing for 2-3 hours, and thus preparing a molten mixture; (3) introducing the molten mixture in the step (2) into a mold, separating the molten mixture from the mold through diaphragm paper, and pressing for molding under the pressure of 70-120kg / cm<2> and at the melting temperature; (4) cooling and sizing the sample in the step (3) under the pressure of 100-150kg / cm<2> and at temperature which is 10-30 DEG C lower than the melting temperature, and cutting into samples with different sizes and shapes. The sample preparation process is simple, the trace components can be uniformly distributed in the sample, and the uniformity requirement of primary standard substances is met.

Description

technical field [0001] The invention relates to a sample preparation method, in particular to a sample preparation method for uniformly distributing trace components in a solid block matrix to prepare spectral standard samples. Background technique [0002] Trace component analysis is one of the hot spots in the field of chemical analysis in recent years. Due to the low content of trace components in the sample, sensitive and accurate testing methods are required. Modern analysis and test methods can generally meet the test requirements, but they are all relative test methods, and trace element standard samples with uniform material, accurate value and good stability must be used as the basis and reference. The mass percentage of trace / ultra-trace components in the sample is extremely small, generally a few parts per million. It is very difficult to distribute such a small component in the sample evenly. In addition, Solid block matrices cannot be directly stirred like liq...

AI Technical Summary

Problems solved by technology

Its advantage is that it can eliminate the inhomogeneity of composition, density and particle size, and completely eliminate the mineral effect and particle size effect. Its main disadvantage is that metal samples cannot be melted directly, and must be pre-oxidized. The melting temperature is high and the requirements for sample preparation equipment are high. , the sample preparation equipment is expensive (melting needs to use materials with higher melting point, such as platinum metal), the cost of sample preparation is high, and it is not suitable for mass production

Due to the addition of flux and flux, the sample is diluted, the intensity of the analysis elements is reduced, the analysis line intensity of light elements is greatly reduced, and the concentration of trace and minor components is also greatly reduced. For light elements and Unfavorable determination of trace elements

In addition, during storage, the vitreous body loses its transparency or cracks due to stress, and the glass disk needs to be remelted and remade.

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