NB/T 11264-2023Determination of arsenic, mercury and selenium in oil shale—Atomic Fluorescence spectrometric method (English PDF)

Foreword

This document complies with the provisions of GB/T 1.1-2020 "Standardization Work Guidelines Part 1: Structure and Drafting Rules of Standardization Documents" Drafting.

1 Scope

This document specifies the method summary, reagents and materials, instruments and equipment, analysis methods for the determination of arsenic, mercury and selenium content in oil shale by atomic fluorescence spectrometry.

Analytical steps, result calculation and expression, method precision and accuracy, quality assurance and quality control.

This document is applicable to the determination of arsenic, mercury and selenium content in oil shale.

The detection limits of arsenic, mercury and selenium content in oil shale determined by atomic fluorescence spectrometry. arsenic 0.0096 µg/g, mercury 0.0019 µg/g, selenium 0.0096µg/g.

2 Normative reference documents

The contents of the following documents constitute essential provisions of this document through normative references in the text. Among them, the dated quotations For undated referenced documents, only the version corresponding to that date applies to this document; for undated referenced documents, the latest version (including all amendments) applies to this document.

GB/T 6379.2 Accuracy of measurement methods and results (correctness and precision) Part 2: Determination of repeatability of standard measurement methods Basic methods of sex and reproducibility

GB/T 6682 Specifications and test methods for water used in analytical laboratories

3 Terms and definitions

There are no terms or definitions to be defined in this document.

4 Method summary

After the sample is digested by microwave, pentavalent arsenic is pre-reduced to trivalent arsenic using thiourea-ascorbic acid under acidic conditions, and then hydroborated.

Potassium is used as a reducing agent to reduce arsenic, mercury and selenium in the sample to arsine gas, mercury vapor and hydrogen selenide. Argon gas is used as the carrier gas to introduce atomization.

In the instrument, the contents of arsenic, mercury and selenium were measured on an atomic fluorescence spectrometer.

5 Reagents and materials

Unless otherwise stated, reagents confirmed to be of analytical grade or above and grade three or above evaporators that comply with GB/T 6682 are used in the analysis. Distilled water or water of equivalent purity.

5.1 Potassium hydroxide.

5.2 Potassium borohydride.

5.3 Thiourea.

5.4 Ascorbic acid.