GB/T 40175.1-2021Textiles—Methods of biochemical analysis—Part 1: Cadmium and lead (colloidal gold method) (English PDF)

1 Scope

This document specifies methods for the determination of extractable cadmium and lead content in textiles by the colloidal gold method.

This document applies to the screening and determination of cadmium and lead in various textile products.

2 Normative references

The contents of the following documents constitute the indispensable clauses of this document through normative references in the text. For dated references, only the version corresponding to that date is applicable to this document; for undated references, the latest version (including all amendments) is applicable to this document.

GB/T 3922, Textiles - Tests for colour fastness - Colour fastness to perspiration

GB/T 6682, Water for analytical laboratory use - Specification and test methods

3 Terms and definitions

There are no terms and definitions that need to be defined in this document.

4 Principle

The cadmium and lead ions in the acidic sweat, after being chelated by the chelating agent, have a color reaction with colloidal gold particles that are labeled with cadmium and lead monoclonal antibodies. The color depth is […]

5 Reagents and materials

c) Series mixed working solutions: respectively draw 1 mL of cadmium standard stock solution and 1 mL of lead standard stock solution in the same 100 mL volumetric flask; use water to dilute to the mark; the concentration of cadmium and lead in this solution are both 1 mg/L. Then, use water to respectively dilute to 0.005 mg/L, 0.01 mg/L, 0.02 mg/L.

5.13 Cadmium chelating agent solution: Dissolve 1 mg of cadmium chelating agent (5.3) in HBS buffer (5.9); completely dissolve; then, use the buffer (5.9) to dilute to 30 mL; set aside.

5.14 Lead chelating agent solution: Dissolve 1 mg of lead chelating agent (5.4) in 1 mL of dimethyl sulfoxide (5.10); completely dissolve; then, use the buffer (5.9) to dilute to 20 mL; set aside.

6 Apparatus and equipment

6.1 pH meter or pH test paper (1~14).

6.2 Balance: sensitivity of 0.01 g and 0.000 1 g.

6.3 Constant temperature water bath oscillator: The temperature control accuracy is ±1 °C; the oscillation frequency accuracy is ±1 time/min.

6.4 Vortex oscillator.

6.5 Timer: accurate to s.

6.6 Dry-type warm bath: The temperature control accuracy is ±1 °C.

6.7 Colloidal gold reader: It can measure and display the measurement results of colloidal gold quantitative test strips.

6.8 Heavy metal cadmium or lead rapid quantitative detection test strip: It is composed of gold-labeled micropores, test strips, and standard curve cards (codes); refrigerated storage is required; for specific storage conditions, refer to the instructions for use. Refer to Appendix A for the performance evaluation requirements of heavy metal cadmium or lead rapid quantitative detection test strips.

6.9 Erlenmeyer flask with stopper: 150 mL.

7 Sample solution preparation

7.1 Take a representative sample; cut it into small pieces below 5 mm × 5 mm; mix well; weigh two parts of 4 g of samples (for parallel testing), accurate to 0.01 g; place them in a Erlenmeyer flask with stopper (6.9); add 80 mL of acidic […]

8 Sample determination

The measurement step needs to be completed within 1 min.

Note: The use of dry-type warm baths and colloidal gold readers of different manufacturers may be different; the operation shall be carried out according to the provisions of the product instructions.

9 Test data processing

The content of cadmium and lead in the sample is automatically calculated and displayed by the reader. Take the average value of the two results, in milligrams per kilogram (mg/kg).

Note: Samples, of which the result is judged to be invalid and positive, are further tested according to GB/T 17593.

10 Precision

In the same laboratory, the same operator uses the same equipment, according to the same test method, and tests the same object under test independently in a short time. The absolute difference between the two independent test results obtained is not greater than 10% of the arithmetic mean of the two measured values, which is based on the condition that it does not exceed 5% for it to be greater than 10% of the arithmetic mean value of these two measured values.

11 Detection limit

The detection limit of cadmium and lead in this method are both 0.1 mg/kg.

12 Test report

The test report shall at least give the following contents:

a) documents used;

b) sample source and description;

c) test result;

d) test date;

e) any details that deviate from this document. […]