GB/T 223 consists of several parts.
This part is Part 88 of GB/T 223.
This part is drafted in accordance with the rules given in the GB/T 1.1-2009
This standard is identical with International Standard ISO 13933:2014 Steel and Iron — Determination of Calcium and Magnesium — Inductively Coupled Plasma Atomic Emission Spectrometric Method.
The Chinese documents consistent and corresponding with the normative international documents in this part are as follows:
— GB/T 6682-2008 Water for Analytical Laboratory Use — Specification and Test Methods (ISO 3696:1987, MOD);
— GB/T 12806-2011 Laboratory Glassware — One-mark Volumetric Flasks (ISO 1042:1998, MOD)
— GB/T 20066-2006 Steel and Iron — Sampling and Preparation of Samples for the Determination of Chemical Composition (ISO 14284:1996, IDT)
For the purposes of this part, the following editorial changes have also been made:
— To be consistent with the existing standard series, name of this part is changed to Iron, Steel and Alloy — Determination of Calcium and Magnesium Contents — Inductively Coupled Plasma Atomic Emission Spectrometric Method.
This part was proposed by China Iron and Steel Association.
This part is under the jurisdiction of the National Technical Committee on Iron and Steel of Standardization Administration of China (SAC/TC 183).
Iron, Steel and Alloy — Determination of Calcium and Magnesium Contents — Inductively Coupled Plasma Atomic Emission Spectrometric Method
1 Scope
This part of GB/T 223 specifies a method for determination of calcium and magnesium contents in iron, cast iron, steel, and alloyed steel by inductively coupled plasma (ICP) atomic emission spectrometry.
This part is applicable to the determination of calcium and magnesium contents (mass fraction) in the range of 0.000 5% to 0.006% and 0.000 5% to 0.20%, respectively.
2 Normative References
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 385 Laboratory Glassware — Burettes
ISO 648 Laboratory Glassware — Single-volume Pipettes
ISO 1042 Laboratory Glassware — One Mark Volumetric Flasks
ISO 3696 Water for Analytical Laboratory Use — Specification and Test Methods
ISO 14284 Steel and Iron — Sampling and Preparation of Samples for the Determination of Chemical Composition)
3 Principle
A test portion is dissolved in a hydrochloric, nitric and hydrofluoric acid mixture and fumed with perchloric acid. Hydrochloric acid, nitric acid, and an internal standard element (if used) are added and the solution is diluted to a known volume. The solution is filtered if necessary, nebulized into an ICP spectrometer and the intensity of the emitted light from each element measured simultaneously with the intensity of the light emitted by the internal standard element.
4 Reagents
During the analysis, unless otherwise stated, use only reagents of recognized analytical grade with very low calcium and magnesium contents and only grade 2 water as specified in ISO 3696.
4.1 Pure iron, containing less than 0.5 μg/g of calcium and magnesium.
4.2 Hydrochloric acid, ρ about 1.19 g/mL.
4.3 Hydrochloric acid, ρ about 1.19 g/mL, diluted 1 + 1.
4.4 Hydrochloric acid, ρ about 1.19 g/mL, diluted 1 + 4.
4.5 Hydrochloric acid, ρ about 1.19 g/mL, diluted 1 + 100.
4.6 Nitric acid, ρ about 1.42 g/mL.
4.7 Hydrofluoric acid, ρ about 1.14 g/mL.
4.8 Perchloric acid, ρ about 1.67 g/mL.
4.9 Acid mixture.
Mix two volumes of hydrochloric acid (4.2), one volume of nitric acid (4.6), and three volumes of water.
4.10 Calcium standard solutions.
4.10.1 Calcium stock solution, 1 000 mg/L.
Dry several grams of calcium carbonate [purity ≥99.9% (mass fraction)] in an oven at 100 °C ± 5 °C for at least 1 h and cool to room temperature in a desiccator. Weigh, to the nearest 0.000 1 g, 2.497 g of the dried product into a 400 mL beaker, add 20 mL of hydrochloric acid (4.3), cover with a watch-glass and heat gently until the product is completely dissolved. Cool to room temperature and transfer the solution into a 1 000 mL one-mark volumetric flask. Dilute to the mark with water and mix.
1 mL of this stock solution contains 1.000 mg of calcium.
4.10.2 Calcium standard solution A, 100 mg/L.
Transfer 10.00 mL of calcium stock solution (4.10.1) into a 100 mL one-mark volumetric flask. Add 10 mL of hydrochloric acid (4.4). Dilute to the mark with water and mix.
1 mL of this standard solution contains 0.100 mg of calcium.
Foreword II
1 Scope
2 Normative References
3 Principle
4 Reagents
5 Apparatus
6 Sampling
7 Test Procedure
8 Expression of Results
9 Test Report
Annex A (Normative) Procedure for the determination of instrumental criteria
Annex B (Informative) Additional Information on International Cooperative Test
Annex C (Informative) Graphical Representation of Precision Data
Bibliography
