YS/T 325.3-2009Methods for chemical analysis of nickel-copper alloy. Part 3: Determination of iron content. The flame atomic absorption spectrometric method (English PDF)

Foreword

YS/T 325-2009 "nickel-copper alloy chemical analysis method" a total of six sections.

--- Part 1. Determination of nickel content Na2EDTA titration

--- Part 2. Determination of copper content - Gravimetric method electrolysis

--- Part 3. Determination of iron content by flame atomic absorption spectrometry

--- Part 4. Determination of manganese content by flame atomic absorption spectrometry

--- Part 5. Determination of aluminum content Na2EDTA titration

--- Part 6. Determination of the amount of titanium di Zhao DAM spectrophotometry this section YS/T Part 3 325.

The partial modification of the use of ISO 7530-5:1990 "nickel alloys by flame atomic absorption spectrometry - Part 5. Determination of iron content" in the main to the technical content of ISO 7530-5:1990 the same structure not correspond exactly to write. Specific technical differences see Standard Appendix A, Appendix B.

The partial replacement of YS/T 325-1994 Determination of iron content in the "nickel-copper alloy (NCu28-2.5-1.5) Methods for chemical analysis." this section compared with YS/T 325-1994, the main changes are as follows.

--- Changed the measurement method, modified by the dichromate method flame atomic absorption spectrometry.

--- Increase the "scope", "Methods and Principles", "instrument" of the content and requirements.

--- Supplementary terms of quality assurance and control, increased precision terms.

This section in Appendix A, Appendix B is an informative annex.

The non-ferrous metal part by the National Standardization Technical Committee and centralized.

This section is responsible for drafting unit. aluminum Shenyang Nonferrous Metals Processing Co., Ltd.

Participated in the drafting of this section. High-tech copper sheets Co., Ltd., Guangzhou Nonferrous Metal Research Institute.

1 Scope

YS/T in this part 325 specifies the method for determination of nickel-copper alloy of iron content.

This section applies to the determination of nickel-copper alloy of iron content. Measurement range. 0.10 to 4.00%.

2 Principle of the method

After the sample was dissolved with nitric acid, and evaporated to dryness. Hydrochloric acid was added to remove nitric acid, hydrochloric acid medium, using air - acetylene flame in atomic absorption Spectrometer wavelength 248.3nm measured absorbance iron. Other elements are added strontium salt to eliminate titanium, silicon element interference (present in the alloy quit Interference measurement).

3 Reagents

Unless otherwise indicated in the analysis using only recognized as analytical grade reagents and distilled or deionized water or equivalent purity.

3.1 hydrochloride (rho1.19g/mL).

3.2 Hydrogen peroxide (300g/L).

3.3 nitric acid (1 + 1).

3.4 HCl (1 + 1).

3.5 strontium chloride solution. 15.2g of strontium chloride hexahydrate (SrCl2 · 6H2O) transferred to 200mL beaker, 100mL of hot water in the (50 °C ~ 60 °C) was dissolved. Cooled and transferred to 1000mL volumetric flask, dilute to the mark and mix.

3.6 iron standard stock solution. Weigh 1.000g metallic iron (iron mass fraction >=99.95%) placed in 400mL beaker, add 30mL of hydrochloric acid (3.4), heated to dissolve completely. Cooled to about 50 °C, 1mL slowly added hydrogen peroxide (3.2) of iron is oxidized to a boil.

Cooled and transferred to 1000mL volumetric flask, add 35mL of hydrochloric acid (3.1), dilute to the mark and mix. This solution containing 1mL 1mg iron.

3.7 iron standard solution. Pipette 50.00mL iron standard stock solution (3.6) into 500mL volumetric flask, add 25mL of hydrochloric acid (3.1), Dilute with water to volume, and mix. This solution 1mL containing 100µg iron.

4 Instrument

Atomic absorption spectrometer, with iron hollow cathode lamp.

Under optimum working conditions for those who can reach the following indicators can be used.

--- Characteristic concentration. In line with the measuring solution matrix solution, characteristic concentration of iron should not exceed 0.12µg/mL.

--- Precision. measuring the absorbance of the standard solution 10 times the highest concentration, the standard deviation does not exceed 1.0% of the mean absorbance; with the lowest concentration of standard solution (not "zero" concentration of the standard) measuring the absorbance of 10 times, the standard deviation should not exceed the maximum concentration 0.5% of the average absorbance of the standard solution.

--- Linear curve. The curve is divided into five sections according to concentration, absorbance difference between the highest and the lowest segment of the segment absorbance difference Ratio of not less than 0.7.

5 Sample

Thickness of less than 1mm debris.