Matrix modifier and method for measuring calcium content by graphite furnace atomic absorption spectrometry

Abstract

The invention discloses a matrix modifier for measuring calcium content by graphite furnace atomic absorption spectrometry. The matrix modifier is added into a diluent and a sample to be measured, thesample to be measured is a pressurized water reactor boric acid medium, and the matrix modifier comprises mannitol. By using the matrix modifier disclosed by the invention, the heating characteristicof a graphite furnace can be optimized, the difference degree of parallel measurement results is reduced, and the problem of serious trailing of an analyte spectral peak is solved, so that the analyte spectral peak is more symmetrical and smooth, and the integral calculation of the analyte spectral peak is more accurate. The complexing effect of a boric acid matrix and calcium is reduced, the atomization degree of calcium is improved, and then the sensitivity of calcium detection is improved. The defect of insufficient matching degree of a standard solution and a sample matrix is overcome, the influence of the matrix on an analysis result is reduced, manual dilution or boric acid addition operation adopted for matching the matrix is avoided, the risk of radioactive contamination to workers is reduced, and the irradiation dose of analysts is reduced.

Description

technical field [0001] The invention relates to the technical field of trace element analysis, in particular to a matrix modifier and a method for measuring calcium content by graphite furnace atomic absorption spectrometry. Background technique [0002] The silicate oxide solubility of calcium has a negative temperature coefficient and preferentially deposits on the hottest fuel element rod surfaces of the reactor coolant system to form dense deposits that reduce heat transfer efficiency and cause localized overheating. Damaged fuel cladding, especially where significant boiling occurs. Therefore, accurate and rapid analysis of Ca content in boric acid medium in the primary circuit of nuclear power plants is the basic requirement of chemical technical specifications for nuclear power plants. [0003] Graphite furnace atomic absorption spectrometer has the advantages of low gas consumption, high sensitivity, good precision, automatic sampling, and simple operation process. ...

AI Technical Summary

Problems solved by technology

[0005] 2. When the conventional method detects calcium, the complex effect of boric acid matrix and calcium makes the atomization of calcium insufficient, the sensitivity of the instrument is too low, and the stability of multiple parallel measurements is insufficient, resulting in insufficient linear correlation of the standard curve. Fluctuation, high detection limit

Matrix modifiers can assist in eliminating the adverse effects caused by the matrix or coexisting ions, but there is no report on matrix modifiers that use boric acid as an interfering substance at home and abroad.

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