GB/T 32603-2016 in English

GB/T 32603-2016 Standard Overview

This standard specifies the method for determining the content of the mobile elements arsenic (Ar, Sb), selenium (Se) and mercury (Hg) in toy materials using atomic fluorescence spectrometry (AFS). This method is applicable to various toy materials, including plastics, coatings, etc.

Background of Standard Formulation

With the popularity of toy products, the risk of children being exposed to harmful heavy metals increases. The formulation of GB/T 32603-2016 aims to ensure that the migration of arsenic, antimony, selenium and mercury in toy materials meets national safety standards and protects children's health.

Technical Principle

This method is based on atomic fluorescence spectrometry and determines the target elements through the following steps:

1. Sample Extraction: Sampling and preparation are carried out according to the GB6675.4 standard procedure.
2. Reagent treatment: Pre-treat the sample with a mixture of thiourea-ascorbic acid, hydrochloric acid solution, and potassium borohydride solution, respectively, to reduce the target element to a hydride state suitable for detection.
3. Atomizer detection: The carrier gas (usually argon) brings the solution to be tested into the atomizer and decomposes it into atoms of the target element at high temperature. Under the excitation of a hollow cathode lamp of a specific wavelength, the atoms produce fluorescence, the intensity of which is proportional to the concentration of the target element.

Instrument and Reagent Requirements

Standard curve and method validation

The preparation and determination process of the standard solution must ensure a good linear relationship, and the correlation coefficient r≥0.995 is usually required. By plotting the fluorescence intensity-concentration curve of a series of standard working solutions, the target element content in the sample can be quantitatively analyzed.

Method precision and deviation control

According to the data in Appendix B, the inter-laboratory determination results show that:

• The repeatability limit of arsenic is r=0.048 mg/L, and the reproducibility limit is R=0.100 mg/L.
• The repeatability limit of antimony is r=0.066 mg/L, and the reproducibility limit is R=0.266 mg/L.

Implementation suggestions

To ensure the accuracy of the test results:

1. Strictly follow the standard operating procedures for sample preparation and reagent preparation.
2. Regularly calibrate the instrument to ensure that the hollow cathode lamp and atomizer are in good working condition.
3. Be careful to avoid cross contamination of glassware, soak it in nitric acid and clean it before use.