GB/T 4372.7-2014Methods for chemical analysis of zinc oxide produced by direct process - Part 7: Determinantion of ferric oxide content - Flame atomic absorption spectrometry method (English PDF)

1 Scope

GB/T 4372 provisions of this part of the determination of the direct method zinc oxide iron oxide content.

This section applies to the determination of zinc oxide direct method of ferric oxide content. Measurement range. 0.010% to 0.10%.

2 Method summary

Samples with hydrochloric acid, nitric acid dissolved, evaporated to dryness, in dilute hydrochloric acid medium, using air - acetylene flame atomic absorption spectrometer wavelength

248.3nm measured absorbance of iron, the standard curve method to calculate the amount of ferric oxide.

3 Reagents

Unless otherwise indicated in the analysis using only confirmed for the gifted class pure reagents and water or an equivalent purity water.

4 Instrument

Atomic absorption spectrometer, with iron hollow cathode lamp.

Under optimum working conditions for those who can reach the following indicators can be used.

Sensitivity. In line with the measurement sample solution matrix blank solution, the characteristic concentration of iron should not exceed 0.3µg/mL.

Precision. standard solution measuring the absorbance of the highest concentration of 10 times, the standard deviation should not exceed the maximum concentration of the standard mean absorbance

0.5% of the luminosity; 10 measuring the absorbance of standard solutions with the lowest concentration (standard solution is not zero), and the standard deviation does not exceed the maximum concentration

0.5% of the mean absorbance of standard solution.

Linear curve. The curve is divided into five sections according to concentration, than the difference between the absorbance of the absorbance difference between the highest and the lowest segment segment, […]