SH/T 0102-1992 Determination of copper content in lubricating oils and liquid fuels (atomic absorption spectrometry)

AI-translated method card — human verification pending. This is not an official translation of the standard. Unclear source values remain unverified; check the original standard and product certificate before use.

Card type: Test method

1. Method number / full title / English name / replacement relationship

• Standard number: SH/T 0102-92
• Chinese full title: Determination of copper content in lubricating oils and liquid fuels (atomic absorption spectrometry)
• English name: not provided in the available source
• Replacement relationship: not provided in the available source (the source text marks "(2000 confirmed)")
• Approval/implementation: approved by China Petrochemical Corporation 1992-06-06, implemented on 1993-01-01
• Reference adoption: Federal Republic of Germany national standard DIN 51404 T2(85) "Direct determination of copper content in lubricating oils and liquid fuels by atomic absorption spectrometry"

2. Scope of application and non-applicability

• Applicable to lubricating oils, used lubricating oils and liquid fuels.
• Not applicable: not provided in the available source.

3. Method principle

After the sample is diluted with solvent naphtha, it is directly sprayed into the flame of an atomic absorption spectrometer, and the absorbance is measured. The absorbance of the sample is compared with the absorbance of the standard solution to calculate the copper content in the sample.

4. Reagents and materials (purity / preparation)

• 4.2.1 Air: purified, oil-free and water-free.
• 4.2.2 Acetylene gas: purity 99.9%.
• 4.2.3 Solvent naphtha for the paint industry: complies with the provisions of SH 0005.
• 4.2.4 White oil for cosmetic use: complies with the provisions for oil No. 15 in SH 0007.
• 5.1 Organic copper salt: analytical reagent grade, with known copper content.
• 5.2 2- Ethylhexanoic acid: chemically pure.
• 6.1 Copper standard stock solution (copper content 5 000 mg/kg): weigh an appropriate amount of organic copper salt (accurate to 0.1 mg) into a 100 mL beaker, add 6 mL 2- ethylhexanoic acid, stir and heat under warm conditions (not exceeding 50℃) to dissolve, cool to room temperature, add white oil to 50 g, and store in a brown glass bottle. Note: The copper standard stock solution can be stored at room temperature protected from light for three months.
• 6.2 Blank solution: solvent naphtha for the paint industry is used as the blank solution.

5. Instruments and equipment

• 4.1.1 Atomic absorption spectrometer: wavelength range 190～900 nm; any atomic absorption spectrometer capable of measuring the copper analytical line within the absorbance range of 0.1～0.5 is applicable.
• 4.1.2 Copper hollow cathode lamp.
• 4.1.3 Volumetric flask: 25 mL.
• 4.1.4 Pipettes: 1, 2, 5, 10 mL.
• 4.1.5 Balance: sensitivity 0.1 mg.

6. Recommended operating conditions

Table 2 Typical instrument working conditions:

Note: The performance of instruments of different models may differ, and the instrument manual should be consulted.

7. Sampling and sample preparation

• 7.2.1 Heat the sample in a water bath to 50～60℃, stir and shake well.
• 7.2.2 Weigh 0.1～0.3 g of sample (accurate to 0.1 mg) into a 25 mL volumetric flask, dilute to the mark with blank solution, shake well and set aside for measurement.

8. Analytical procedure

• 7.1 Prepare standard solutions: pipette an appropriate amount of copper standard stock solution into a 25 mL volumetric flask, add 2 mL white oil, dilute with blank solution so that the concentrations given in Table 1 are reached.

Table 1:

Note: ① The standard solutions must be prepared on the day of the test. ② The standard solutions may be brought to the required concentration by two dilutions. ③ The amount of white oil added should make the viscosity basically consistent with that of the sample. (Note: The correspondence between the values in the "Concentration" row and the serial number column in Table 1 requires confirmation against the source standard (source-text extraction); the original table header and values are misaligned.)

• 7.3.2 Zero the instrument with blank solution.
• 7.3.3 Measure the absorbance of the sample solution.
• 7.3.4 Measure the absorbance of the standard solution closest to the absorbance of the sample solution.
• 7.3.5 Measure the absorbance of the sample solution.
• 7.3.6 Measure the absorbance of the standard solution closest to the absorbance of the sample solution.
• 7.3.7 Zero with blank.
• 7.3.8 Repeat steps 7.3.2～7.3.7, and use the average of the two absorbance values as the measurement result.
• Note: ① High-content samples can be measured by changing the optical path length, reducing the sample weight, or dilution. ② During the interval between measurements of the standard solution and the sample solution, blank solution must be continuously sprayed in to maintain constant measurement conditions.

9. Qualitative and quantitative determination and calculation formula

The copper content in the sample X (mg/kg) is calculated according to the following formula:

X = (A · C · f · 25) / (A₀ · m)

Where:

• A—— average absorbance of copper in the sample solution;
• A₀——average absorbance of the standard solution with copper concentration close to that in the sample;
• C—— concentration of the standard solution corresponding to A₀, mg/kg (the unit in the source text at source-text extraction is "fi『L", requires confirmation against the source standard (source-text extraction));
• f—— dilution factor;
• m—— sample mass, g;
• 25—— sample solution volume, mL.

10. Precision

The reliability of the test results is judged according to the following provisions (95% confidence level).

• 9.1 Repeatability: the difference between two results obtained by the same operator in repeated determinations shall not exceed 10% of the arithmetic mean.
• 9.2 Reproducibility: the difference between two results submitted by different laboratories shall not exceed 30% of the arithmetic mean.
• The above precision was obtained from statistical tests on samples in the range of 5～100 mg/kg.

11. Report

Take the arithmetic mean of two repeated determination results as the determination result, and round to an integer.

12. Referenced documents

• SH 0005 Solvent naphtha for the paint industry
• SH 0007 White oil for cosmetic use

13. Source and verification

This page is an AI translation of the available Chinese method card. Human verification is pending. It is not an official translation of the standard. Check the source standard and product certificate before use.

14. Quick-reference Q&A