GB/T 12684-2018 in English

In-depth interpretation of the National Standard of the People's Republic of China GB/T 12684—2018

1. Overview of the standard and scope of application

GB/T 12684—2018 is the latest version of "Analysis Method for Industrial Borides", which replaces GB/T 12684—2006. This standard is mainly applicable to the determination of various substances in industrial boric acid, boron oxide and related compounds, including:

• Boric acid content
• Water-insoluble matter content
• Sulfate content
• Heavy metal and arsenic content
• Impurity elements (sodium, iron, calcium, magnesium, aluminum, silicon dioxide)
• Anions (fluorine, chlorine, bromine, sulfate, nitrate, phosphate)
• Boron isotope abundance ratio ($^{10}\mathrm{B}/{}^{11}\mathrm{B}$)

2. Standard Update Background and Technological Evolution

Compared with GB/T 12684-2006, the new standard mainly adds the following contents:

3. Interpretation of key analytical methods

The following is a detailed interpretation of several core test items:

3.1 Determination of boric acid content (mannitol enhancement method)

Principle: Use mannitol to strengthen boric acid, titrate with sodium hydroxide standard titration solution, and determine the end point by color change.

Steps:

1. Weigh the sample and add water to dissolve
2. Add mannitol or invert sugar solution as a stabilizer
3. Titrate with sodium hydroxide standard titration solution to a specified color
4. Calculate the boric acid content

3.2 Determination of sulfate content (turbidimetric method)

Principle: In an acidic medium, sulfate reacts with barium chloride to form barium sulfate precipitation, and the content is determined by turbidimetry with a standard solution.

Key steps: The use of colorimetric tubes and pipette is the key to ensuring accuracy.

3.3 Anion determination (ion chromatography)

Principle: Utilize ion chromatography separation technology in combination with a conductivity detector to achieve efficient separation and quantitative analysis of anions.

Instrument: Ion chromatograph with a conductivity detector is the core equipment of this method.

4. Recommendations for quality control and data processing

To ensure the accuracy of test results, the following measures are recommended:

• Strictly control reagent purity and preparation accuracy
• Regularly calibrate instruments and equipment
• Establish a standard curve and conduct a blank test
• Perform parallel measurements to ensure consistency of results

5. Implementation Recommendations

In actual operations, the following points should be noted:

Conclusion

GB/T 12684—2018 provides a comprehensive analysis method for industrial borides, which is suitable for product quality control and scientific research needs. Laboratories should select appropriate test schemes based on actual conditions and strictly follow the quality control requirements in the standard when implementing.