GB/T 4103.14-2009Methods for chemical analysis of lead and lead alloys - Part 14: Determination of cadmium content - Flame atomic absorption spectrophotometry (English PDF)

1 Scope

This Part of GB/T 4103 specifies the determination of cadmium content in lead and lead-cadmium alloys.

This Part applies to the determination of cadmium content in lead and lead- cadmium alloys.

Measuring range: 0.000 1% -0.01%; 0.3% – 2.0%.

2 Methods and Principles

Samples shall be dissolved in nitrate; USE lead sulfate to precipitate and separate lead; USE air-acetylene flame, at wavelength 228.8 nm of atomic absorption spectrometer, to measure absorbance of cadmium. USE standard curve method to calculate cadmium content.

3 Reagents

Unless otherwise stated, water used to prepare the solution and analysis in this test shall be Grade 1 Water; all test utensils used in the test shall be immersed with dilute nitrate (1 + 4), and shall be thoroughly washed with Grade 1 Water.

3.1 Nitrate (rho 1.42 g / mL), superior grade purity.

3.2 Sulfate (rho 1.84 g / mL); superior grade purity.

3.3 Nitrate (1 + 1).

3.4 Nitrate (1 + 3).

3.5 Sulfate (1 + 1).

4 Instruments

Atomic absorption spectrometer, attached with cadmium hollow cathode lamp.

Under the optimum working conditions; those instruments which can achieve the following targets may be used.

- Characteristic concentration: In solution consistent with the matrix of measuring sample solution, the characteristic concentration of cadmium shall be less than 0.05 µg / mL;

- Precision: USE standard solution of the highest concentration to measure absorbance for 10 times, its standard deviation shall not exceed 1.0% of the average absorbance; USE standard solution of the lowest concentration (not the standard solution of “zero” concentration) to measure absorbance for 10 times, its standard deviation shall not exceed 0.5% of the average absorbance of standard solution of the highest concentration;

- Linearity of working curve: DIVIDE the working curve into five sections equally, based on concentration; the ratio between the absorbance difference of the highest section AND the absorbance difference of the lowest section shall not be less than 0.8;

Reference operating conditions of the instruments are shown in Table 1.

Table 4

Mass factor of cadmium / %

0.0002

0.0020 0.0050

0.50 1.00 1.50

R / % 0.0001

0.0005 0.0010

0.04 0.05 0.06

Note: Reproducibility (R) is 2.8SR; SR is the reproducibility standard deviation.

8 Quality assurance and control

Standard samples of national-level or industrial-level shall be used (when these

2 samples are not available, controlled standard sample may be used for substitution); effectiveness of this analytical method shall be calibrated weekly or biweekly. When the process is out of control, root cause shall be found out;

After the error is corrected, calibration shall be repeated.

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References and Original Chinese Documents

[1] GB/T 4103.14-2009 Methods for chemical analysis of lead and lead alloys - Part

14: Determination of cadmium content - Flame atomic absorption

ID=GB/T%204103.14-2009