GB/T 4348.3-2012Sodium hydroxide for industrial use - Determination of iron content-1, 10-phenanthroline photometric method (English PDF)

1 Scope

This standard specifies the 1,10-phenanthroline spectrophotometry method hydroxide for industrial use in the iron content.

This standard applies to iron content greater than or equal to 0.00005% (mass fraction) of industrial products with sodium hydroxide.

2 Normative references

The following documents for the application of this document is essential. For dated references, only the dated edition applies to this article

Member. For undated references, the latest edition (including any amendments) applies to this document.

GB/T 603 Test Methods Chemicals Preparations with

GB/T 6682 analytical laboratory use specifications and test methods (GB/T 6682-2008, ISO 3696. 1987, MOD)

Principle 3

Ascorbic acid in the sample solution is reduced to Fe3 Fe2, at a pH of from 4 to 6.00, Fe2 with 1,10-phenanthroline generated orange red envelope

. Compound Maximum absorption wavelength in a spectrophotometer (510nm) absorbance was measured at a reaction formula is as follows.

2Fe3 C6H8O -> 6 2Fe2 C6H6O6 2H

Fe2 3C12H8N -> 2 [Fe (C12H8N2) 3] 2

4 Reagents and materials

The method of the reagents and water, did not indicate when the other requirements, refer to the three water analytical reagent and GB/T 6682 stipulated.

Standard test solution required, the formulations and products, in addition to the provisions of this standard, according to GB/T 603 regulations prepared.