GB/T 20975.20-2020Methods for chemical analysis of aluminium and aluminium alloys—Part 20: Determination of gallium content—Butyrhodamine B spectrophotometric method (English PDF)

Foreword

GB/T 20975 "Methods for Chemical Analysis of Aluminum and Aluminum Alloys" is divided into 37 parts.

---Part 1: Determination of mercury content;

---Part 2: Determination of arsenic content;

---Part 3: Determination of copper content;

---Part 4: Determination of iron content;

---Part 5: Determination of silicon content;

---Part 6: Determination of cadmium content;

---Part 7: Determination of manganese content;

---Part 8: Determination of zinc content;

---Part 9: Determination of lithium content by flame atomic absorption spectrometry;

---Part 10: Determination of tin content;

---Part 11: Determination of lead content;

---Part 12: Determination of titanium content;

---Part 13: Determination of vanadium content;

---Part 14: Determination of nickel content;

---Part 15: Determination of boron content;

---Part 16: Determination of magnesium content;

---Part 17: Determination of strontium content;

---Part 18: Determination of Chromium Content;

---Part 19: Determination of Zirconium Content;

---Part 20: Determination of Gallium Content Butyl Rhodamine B Spectrophotometry;

---Part 21: Determination of calcium content;

---Part 22: Determination of beryllium content;

---Part 23: Determination of antimony content;

---Part 24: Determination of total rare earth content;

---Part 25: Determination of element content by inductively coupled plasma atomic emission spectrometry;

---Part 26: Determination of carbon content by infrared absorption method;

---Part 27: Determination of cerium, lanthanum and scandium content by inductively coupled plasma atomic emission spectrometry;

---Part 28: Determination of cobalt content by flame atomic absorption spectrometry;

---Part 29: Determination of molybdenum content thiocyanate spectrophotometric method;

---Part 30: Determination of hydrogen content by heating extraction thermal conductivity method;

---Part 31: Determination of phosphorus content molybdenum blue spectrophotometry;

---Part 32: Determination of Bismuth Content;

---Part 33: Determination of potassium content by flame atomic absorption spectrometry;

---Part 34: Determination of sodium content by flame atomic absorption spectrometry;

---Part 35: Determination of Tungsten Content Thiocyanate Spectrophotometric Method;

---Part 36: Determination of silver content by flame atomic absorption spectrometry;

--- Part 37: Determination of Niobium Content.

This part is Part 20 of GB/T 20975.

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

This Part replaces GB/T 20975.20-2008 "Methods for Chemical Analysis of Aluminum and Aluminum Alloys Part 20: Determination of Gallium Content Butyl Rhodamine B spectrophotometry. Compared with GB/T 20975.20-2008, in addition to editorial changes, the main technical changes are as follows.

---Added standard use safety warning;

---Modified the measurement range from 0.005%~0.050% to 0.0050%~0.12% (see Chapter 1, Chapter 1 of the 2008 edition chapter).

--- Added "Normative Reference Documents" (see Chapter 2);

--- Added "Terms and Definitions" (see Chapter 3);

---Added requirements for reagents and water used in analysis (see Chapter 5);

--- Added "Test Report" (see Chapter 11).

1 Scope

This part of GB/T 20975 specifies the butyl rhodamine B spectrophotometric method for the determination of gallium content in aluminum and aluminum alloys.

This section applies to the arbitration determination of gallium content in aluminum and aluminum alloys, the measurement range. 0.0050% ~ 0.12%.

2 Normative references

The following documents are indispensable for the application of this document. For dated reference documents, only the dated version applies to this document. For undated references, the latest version (including all amendments) applies to this document.

GB/T 8005.2 Terminology of Aluminum and Aluminum Alloy Part 2: Chemical Analysis

GB/T 8170-2008 Numerical rounding rules and the expression and determination of limit values

3 Terms and definitions

The terms and definitions defined in GB/T 8005.2 apply to this document.

4 Method summary

The sample is dissolved in hydrochloric acid, ferric iron is reduced with titanium trichloride, and GaCl-4 and butyl rhodamine are extracted with benzene in a 6 mol/L hydrochloric acid medium B generates a purple-red complex, and its absorbance is measured at a wavelength of 565nm with a spectrophotometer to determine the gallium content.

5 Reagents

Unless otherwise stated, only reagents and laboratory secondary water confirmed to be analytically pure are used in the analysis.

5.1 Hydrogen peroxide (rho=1.10g/mL).

5.2 Benzene.

5.3 Titanium trichloride solution (15%~20%).

5.4 Hydrochloric acid (6mol/L). Pipette 500mL hydrochloric acid (rho=1.19g/mL) and dilute with water to 1000mL, and mix.

5.5 Butylrhodamine B solution (4g/L). Weigh 0.40g of butylrhodamine B and place it in a beaker, add hydrochloric acid (5.4) to dissolve, then transfer In a 100mL volumetric flask, dilute to the mark with hydrochloric acid (5.4) and mix well.

5.6 Gallium standard storage solution. Weigh 0.2688g of gallium trioxide (>=99.99%) that has been burned at 800°C for 1 hour in a 100mL beaker In the middle, cover with a watch glass, add 20 mL of hydrochloric acid (5.4), heat on a water bath to completely dissolve, cool to room temperature, transfer the solution with hydrochloric acid (5.4) […]