GB/T 36764-2018 in English

Interpretation of GB/T 36764-2018 National Standard of the People's Republic of China

Background and Significance of the Standard

GB/T 36764-2018 "Determination of Heavy Metal Content in Precipitated Hydrated Silica in Rubber Compounds by Inductively Coupled Plasma Atomic Emission Spectrometry" is a national standard formulated for the detection of heavy metal content in precipitated hydrated silica (white carbon black) used in the rubber industry. The standard was issued in 2018, and the main drafting units include Double Coin Tire Group Co., Ltd., Zhonghao Heiyuan Chemical Research and Design Institute Co., Ltd., etc.

Comparison of standard frameworks

Detailed explanation of standard content

GB/T 36764-2018 specifies the method of using inductively coupled plasma atomic emission spectrometer (ICP-OES) to determine the content of heavy metals in precipitated hydrated silica. Its main contents include:

1. Sample preparation and analysis steps

The sample is dissolved in mixed acid and then fixed to volume, and the concentration of heavy metal elements is determined using ICP-OES. The specific process is as follows:

1. Weigh the sample and add mixed acid (hydrofluoric acid, nitric acid) to dissolve.
2. Prepare standard working solution and establish a standard curve.
3. Test the blank solution and sample solution, and calculate the heavy metal content.

2. Key technical parameters

Instrument working conditions include:

• Cooling gas flow rate: 12.00 L/min
• Auxiliary gas flow rate: 1.00 L/min
• Nebulizer gas flow rate: 0.75 L/min
• Plasma power: 1420 W

3. Data processing and quality control

The calculation formula is as follows:

Wherein, $X_i$ is the heavy metal content in the sample (mg/kg), $c$ is the sample solution concentration (mg/L), $c_0$ is the blank solution concentration (mg/L), $V$ is the constant volume (mL), and $m$ is the sample mass (g).

Implementation recommendations