GB/T 6276.6-2010Determination of ammonium hydrogen carbonate for industrial use -- Part 6: Iron content -- O-phenathroline spectrophotometric method (English PDF)

Foreword

GB/T 6276 "industrial use - Determination of ammonium bicarbonate method" is divided into nine sections.

--- Part 1. ammonium bicarbonate content of acid-base titration;

--- Part 2. potentiometric titration of chloride content;

--- Part 3. sulphide content Visible turbidimetric method;

--- Part 4. sulphate content Visible turbidimetric method;

--- Part 5. ash content by weight method;

--- Part 6. iron content - Phenanthroline spectrophotometric method;

--- Part 7. arsenic content diethyl dithiocarbamate silver spectrophotometry;

--- Part 8. arsenic content Gutzeit method;

--- Part 9. heavy metal content Visible turbidimetric method.

This part of GB/T 66276 Part of.

This Part replaces GB/T 6276.6-1986 "industrial use - Determination of iron content in ammonium bicarbonate phenanthroline spectrophotometry." this part of ISO 6685. 1982 is not equivalent degree of consistency.

This portion of the GB/T 6276.6-1986 The main differences are.

--- Reagent solution, standard titration solution preparation and calibration methods such as the implementation of HG/T 2843 standards;

--- Increasing the parallel determination results allow poor regulations.

This part is proposed by the China Petroleum and Chemical Industry Association.

This part of the National Standardization Technical Committee centralized fertilizer and soil conditioner.

This section drafted by. National Fertilizer Quality Supervision and Inspection Center (Shanghai).

1 Scope

GB/T 6276 provisions of this part using phenanthroline spectrophotometric determination of iron content in industrial ammonium bicarbonate.

This section applies to industrial use ammonium bicarbonate Determination of iron content.

2 Normative references

The following documents contain provisions which, through reference to GB/T 6276 to the present, constitute provisions of this section. For dated reference documents Member, all subsequent amendments (not including errata content) or revisions do not apply to this section, however, encouraged to reach under this section Parties to research agreement to use the latest versions of these documents. For undated reference documents, the latest versions apply to this section.

HG/T 2843 fertilizer products for chemical analysis commonly used standard titration solution, standard solution, reagent solution and indicator solution Principle 3 Reduction with ascorbic acid test solution of ferric ions into ferrous ions, at a pH of from 2 to 9.00, a divalent iron ions with phenanthroline Phen generated orange-red complex, the maximum absorption wavelength at 510nm, absorbance was measured with a spectrophotometer to calculate the iron content.

4 Instrument

General laboratory equipment 4.1;

4.2 spectrophotometer with 1cm or 3cm cuvette.

5 Reagents and materials

This standard reagent solution and water, in the specifications and method of preparation is not specified, it shall comply with the provisions of HG/T 2843's.

5.1 hydrochloric acid solution, c (HCl) = 1mol/L;

5.2 ammonia solution, 2.5%;

5.3 pairs nitrophenol indicator solution, 1g/L;

5.4 acetic acid - sodium acetate buffer solution, pH value of about 4.5;

5.5 ascorbic acid solution, 20g/L, the solution was stored in a brown bottle, the use of about 1Od;

5.6 phenanthroline solution, 2g/L;

5.7 iron standard solution, 1mg/mL;

5.8 iron standard solution, 0.01mg/mL, diluted 100-fold with accurate iron standard solution (5.7), the day of use.

6 Step, Analysis

Draw standard curve 6.1