GB/T 39804-2021 in English

GB/T39804-2021 specifies a systematic detection method for leachable harmful substances in wall materials, covering 14 indicators such as heavy metal elements (lead, cadmium, chromium, etc.), hexavalent chromium, anions (F-, Cl-, etc.), pH value, etc. The standard establishes a multi-indicator collaborative detection system for the first time, enabling a single leaching solution to complete all project detection.

Core testing equipment includes:

• Inductively coupled plasma optical emission spectrometer (detection limit 0.1μg/L)
• Graphite furnace atomic absorption spectrometer (Cadmium detection up to 0.01μg/L)
• Ion chromatograph (anion separation column requirements)

All glassware must comply with GB/T12805 Grade A standard, and the filter membrane pore size must be ≤0.45μm.

Preparation of leaching solution:After the sample is ground to 80μm, add water at a solid-liquid ratio of 1:2 and stir for 8h+stand for 64h. The temperature is controlled at (23±2)℃ during the whole process.

Acidity adjustment:Different detection methods need to have a unified acidity (e.g. ICP-MS requires 1% nitric acid medium).

Quality control requirements:The blank test recovery rate must be between 80-120%, and the relative deviation of parallel samples must be ≤5%.

1. Method selection:ICP-OES is preferred for high-content heavy metals, and ICP-MS is used for trace detection (e.g., the detection limit for mercury is 0.2μg/L)

2. Interference elimination: When detecting hexavalent chromium, the pH should be controlled at 2.1-2.5 to avoid conversion of trivalent chromium

3. Data rounding: According to GB/T8170, ≥1mg/L retains 1 decimal place, <1mg/L retains 2 decimal places

Compared with the old version of the standard, the 2021 version has the following major improvements:

• Three new trace detection methods, including ICP-MS, were added
• Unify the leaching procedure (the original standard has multiple leaching methods)
• Add formaldehyde and other organic matter detection indicators