GB/T 5195.12-2025 Methods for chemical analysis of fluorspar—Part 12: Determination of arsenic content English, Anglais, Englisch, Inglés, えいご
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ICS 73.080 CCS D 52
National Standard of the People's Republic of China
GB/T 5195.12-2025
Replace GB/T 5195.12-2016, GB/T 5195.19-2018
Methods for Chemical Analysis of Fluorspar—
Part 12: Determination of Arsenic Content
Issued: 2025-08-29
Implemented: 2026-03-01
Issued by:
State Administration for Market Regulation
Standardization Administration of China
Contents
Foreword
Introduction
1 Scope
2 Normative References
3 Terms and Definitions
4 Method 1: Atomic Fluorescence Spectrometry
5 Method 2: Silver Diethyldithiocarbamate Photometry
6 Test Report
Methods for Chemical Analysis of Fluorspar—Part 12: Determination of Arsenic Content
Warning—Personnel using this document shall have formal laboratory working experience. This document does not indicate all possible safety issues. Users are responsible for taking appropriate safety and health measures and ensuring compliance with relevant national regulations.
1 Scope
This document describes methods for the determination of arsenic content in fluorspar, including atomic fluorescence spectrometry (Method 1) and silver diethyldithiocarbamate photometry (Method 2).
This document is applicable for the determination of arsenic content in fluorspar. The determination range of atomic fluorescence spectrometry (mass fraction): 0.000010% to 0.0100%; the determination range of silver diethyldithiocarbamate photometry (mass fraction): 0.00020% to 0.0500%.
2 Normative References
The following documents contain provisions which, through reference in this text, constitute essential provisions of this document. For dated references, only the editions cited apply; for undated references, the latest edition (including any amendments) applies.
GB/T 6379.1 Accuracy (trueness and precision) of measurement methods and results—Part 1: General principles and definitions
GB/T 6379.2 Accuracy (trueness and precision) of measurement methods and results—Part 2: Basic method for the determination of repeatability and reproducibility of standard measurement methods
GB/T 6682 Specification and test methods for water for analytical laboratory
GB/T 8170 Rules for rounding off numerical values and expression of limiting values
GB/T 12806 Laboratory glassware—Volumetric flasks
GB/T 12807 Laboratory glassware—Graduated pipettes
GB/T 12808 Laboratory glassware—Single-mark volumetric pipettes
GB/T 21191 Atomic fluorescence spectrometer
GB/T 22564 Fluorspar—Sampling and sample preparation
3 Terms and Definitions
No terms and definitions need to be defined in this document.
4 Method 1: Atomic Fluorescence Spectrometry
4.1 Principle
The test sample is dissolved with nitric acid and perchloric acid. In dilute hydrochloric acid medium, arsenic(V) is reduced to arsenic(III) by adding thiourea-ascorbic acid mixed solution. In the hydride generator, arsenic is reduced to hydride by potassium borohydride, introduced into the quartz furnace atomizer by argon, and the fluorescence intensity of arsenic is measured on the atomic fluorescence spectrometer. The arsenic content is calculated by the standard curve method.
4.2 Reagents and Materials
Only analytical grade or higher purity reagents recognized in the analysis shall be used, and only water of grade II or equivalent purity as specified in GB/T 6682 shall be used.
4.2.1 Potassium borohydride.
4.2.2 Sodium hydroxide.
4.2.3 Thiourea.
4.2.4 Ascorbic acid.
4.2.5 Hydrochloric acid, ρ about 1.19 g/mL.
4.2.6 Nitric acid, ρ about 1.42 g/mL.
4.2.7 Perchloric acid, ρ about 1.76 g/mL.
4.2.8 Hydrochloric acid, 1+1.
4.2.9 Hydrochloric acid, 1+19.
4.2.10 Nitric acid, 1+9.
4.2.11 Sodium hydroxide solution, 100 g/L.
4.2.12 Phenolphthalein ethanol solution, 1 g/L.
4.2.13 Potassium borohydride solution, 20 g/L: Weigh 10.0 g of potassium borohydride and 2.5 g of sodium hydroxide, dissolve in water and dilute to 500 mL. Prepare fresh before use.
4.2.14 Thiourea-ascorbic acid solution, 50 g/L: Weigh 5.0 g each of thiourea and ascorbic acid, dissolve in water and dilute to 100 mL. Prepare fresh before use.
4.2.15 Arsenic standard stock solution, 100 μg/mL: Accurately weigh 0.132 0 g of primary arsenic trioxide dried at 100 ℃ to 105 ℃ for 1 h and cooled to room temperature in a desiccator in a 100 mL beaker, add 10 mL of sodium hydroxide solution (4.2.11), heat at low temperature to dissolve, add 10 mL of water and 2 drops of phenolphthalein ethanol solution (4.2.12), neutralize with hydrochloric acid (4.2.8) until the red color just disappears, then add 5 mL in excess, transfer to a 1 000 mL volumetric flask, dilute to volume with water and mix. This solution contains 100 μg of arsenic per mL. Or use certified standard solutions.
4.2.16 Arsenic standard solution, 1 μg/mL: Pipette 1.00 mL of arsenic standard stock solution (4.2.15) into a 100 mL volumetric flask, add 5 mL of nitric acid (4.2.6), dilute to volume with water and mix. This solution contains 1.00 μg of arsenic per mL.
4.2.17 Arsenic standard solution, 10 ng/mL: Pipette 1.00 mL of arsenic standard solution (4.2.16) into a 100 mL volumetric flask, add 5 mL of nitric acid (4.2.6), dilute to volume with water and mix. This solution contains 10 ng of arsenic per mL.
4.2.18 Argon, purity greater than 99.99%.
