SN/T 0838.2-2015Determination of cobalt in boric acid and borax for import and export - Flame atomic absorption spectrometry (English PDF)

Foreword

SN/T 0838 is divided into five sections.

--- SN/T 0838.1-2015 import and export of boric acid and borax Determination of chromium content - Flame atomic absorption spectrophotometry;

--- SN/T 0838.3-2015 import and export of boric acid and borax Determination of nickel content - Flame atomic absorption spectrophotometry;

--- SN/T 0838.4-2015 import and export of boric acid and borax Determination of manganese content - Flame atomic absorption spectrophotometry;

--- SN/T 0838.5-2015 import and export of boric acid and borax copper content determination method of flame atomic absorption spectrophotometry.

This section SN/T Section 20838 of.

This section drafted in accordance with GB/T 1.1-2009 given rules.

The partial replacement of SN/T 0838.2-1999 "export of boric acid and borax Determination of cobalt content." This portion of the SN/T 0838.2-Compared to 1999, the main technical changes are as follows.

--- Increased by flame atomic absorption spectrophotometry;

--- Remove the normative references in standards for sampling;

--- Remove the 3.4 "Sampling" section.

This section points proposed and managed by the National Certification and Accreditation Administration Committee.

1 Scope

SN/T 0838 provisions of this part of the flame atomic absorption spectrophotometry boric acid and borax in cobalt content approach.

This section applies to the determination of the import and export of boric acid and borax in cobalt content was measured in the range of 0.20mg/kg ~ 75.00mg/kg.

2 Normative references

The following documents for the application of this document is essential. For dated references, only the dated version suitable for use herein Member. For undated references, the latest edition (including any amendments) applies to this document.

Laboratory use specifications and test methods GB/T 6682 Analysis

3 Method summary

The sample was 2% nitric acid dissolved in a boiling water bath in nitric acid medium by atomic absorption spectrophotometer at a wavelength of 240.7nm Department to Air - acetylene flame measured absorbance of cobalt.

4 Reagents and materials

Unless otherwise indicated, only recognized as a superior grade pure steamed or acid-treated chemical reagent system, water for the two water GB/T 6682 regulations.

4.1 nitric acid (rho = 1.4g/mL).

4.2 2% nitric acid solution. Apply nitric acid (4.1) and water were mixed volume ratio of 2.98.

4.3 cobalt standard stock solution. concentration of 1000µg/mL, using commercially available certified cobalt standard solution.

4.4 cobalt standard working solution. accurate Pipette the appropriate amount of cobalt standard stock solution (4.3) with 2% nitric acid solution (4.2) by serial dilution, the concentration of the solution of 10µg/mL.

5 Apparatus

5.1 Atomic absorption spectrophotometer. with cobalt hollow cathode lamp, working conditions, see Appendix A.

5.2 Analysis of balance. a sense of the amount of 0.1mg.

5.3 flask. 50mL, 100mL.

5.4 tube. 25mL.

Pipette 5.5. 1mL, 5mL, 10mL.

6 Measuring step