SN/T 5249-2020Determination of iron, manganese, copper, aluminum, titanium, lead, chromium, calcium, magnesium, zinc, potassium, sodium content in precipitated hydrated silica by inductively coupled plasma atomic emission spectrometry (English PDF)

Foreword

This standard was drafted in accordance with the rules given in GB/T 1.1-2009.

This standard was proposed and managed by the General Administration of Customs of the People's Republic of China.

Drafting organizations of this standard. Xiamen Customs of the People's Republic of China, Chongqing Customs of the People's Republic of China, Fujian Zhengsheng Inorganic Materials Stock Co., Ltd.

1 Scope

This standard specifies the inductively coupled plasma atomic emission spectrometry (ICP-AES) for the determination of precipitated hydrated silica (commonly known as white carbon) Black) method of iron, manganese, copper, aluminum, titanium, lead, chromium, calcium, magnesium, zinc, potassium and sodium content.

This standard applies to the content of iron, manganese, copper, aluminum, titanium, lead, chromium, calcium, magnesium, zinc, potassium and sodium in precipitated hydrated silica.

Determination. The elements and measurement ranges are shown in Table 1.

2 Normative references

The following documents are indispensable for the application of this document. For dated reference documents, only the dated version applies to this article Pieces. For undated reference documents, the latest version (including all amendments) is applicable to this document.

GB/T 602 Preparation of standard solutions for impurity determination of chemical reagents GB/T 6682 Analytical laboratory water specifications and test methods

3 Method summary

The test sample was digested with hydrofluoric acid and perchloric acid, in which the silicon was volatilized in the form of silicon tetrafluoride. Dissolve the residue in a hydrochloric acid solution in, the test solution is measured with an inductively coupled plasma atomic emission spectrometer, and the content of each element is determined according to the calibration curve.

4 Reagents and materials

4.1 Unless otherwise specified, only superior grade pure reagents are used, and the experimental water should meet the requirements of secondary water specified in GB/T 6682.

4.2 Hydrofluoric acid (rho=1.13 g/mL).

4.3 Perchloric acid (rho=1.76 g/mL).

4.4 Hydrochloric acid (rho=1.19 g/mL).

4.5 Hydrochloric acid solution (5 95).

4.6 Single element standard solution (1 000 µg/mL). iron, manganese, copper, aluminum, titanium, lead, chromium, calcium, magnesium, zinc, potassium and sodium standard solution the solution is prepared according to GB/T 602 method, or directly purchase a certified standard solution.

4.7 Mixed standard solution series. prepared by diluting each element standard solution (4.6) step by step, the medium is hydrochloric acid solution (4.5), the concentration of each element in the mixed solution of the calibration curve series is shown in Table 2.

5 Apparatus and equipment

5.1 Inductively coupled plasma atomic emission spectrometer, equipped with hydrofluoric acid resistant sampling system. Refer to Appendix A for the working conditions of the instrument.

5.2 Analytical balance. the accuracy is 0.1 mg.

5.3 Oven. The temperature can be maintained at 105 °C ± 5 °C.

5.4 Platinum crucible, with a volume of about 75 mL.

5.5 Electric heating plate.

6 Analysis steps

7 Result calculation

The content of each element is calculated by mass fraction w, and the value is expressed in mg/kg, calculated according to formula (1).

Where.

ci-the concentration of the measured element in the sample, in micrograms per milliliter (µg/mL);

c0--Concentration of sample blank, in micrograms per milliliter (µg/mL);

V--The volume of the sample solution, the unit is milliliters (mL);

m--the mass of the sample, the unit is grams (g).

Note. The calculation result is the average of two parallel determination results, and two decimal places are retained.

8 Precision

The precision was determined by 8 laboratories on 6 levels of samples, and the results were determined after statistical data. The results are shown in Table 3.

Note. m is the average of two determination results.

Appendix A

(Informative appendix) Instrument working conditions