GB/T 4325.20-2013Methods for chemical analysis of molybdenum - Part 20: Determination of manganese content - Flame atomic absorption spectrometry (English PDF)

1 Scope

GB/T 4325 provisions of this part of the determination of molybdenum and manganese contents.

This section applies to molybdenum powder, molybdenum, pure molybdenum trioxide, ammonium molybdate determination of manganese content. Measurement range. 0.0002% to 0.100%.

2 Method summary

Sample to hydrogen peroxide, nitric acid or nitric acid, hydrochloric acid decomposition. Respectively, in dilute nitric acid or hydrochloric acid medium, atomic absorption spectrometer wavelength

279.5nm at the air - acetylene flame measured absorbance.

3 Reagents

Unless otherwise indicated in the analysis using only recognized as analytical grade reagents and distilled or deionized water or equivalent purity.

4 Instrument

Atomic absorption spectrometer, with a manganese hollow cathode lamp.

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

--- Characteristic concentration. the test solution consistent with the determination of the base solution, the characteristic concentration of manganese should not exceed 0.02µg/mL.

--- Precision. measure up to 10 times the standard solution, the absorbance of the standard deviation should not exceed 1.5% of the average absorbance; the lowest

Concentration of standard solution (not "zero" concentration of the standard) measuring the absorbance of 10 times, the standard deviation should not exceed the maximum concentration standard

0.5% average standard solution absorbance.

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

Ratio of not less than 0.7.

5 Sample

Molybdenum should smash through the 0.75mm standard sieve.