SH/T 0749-2004 Determination of Additive Elements Content in Lubricating Oils and Additives (Inductively Coupled Plasma Atomic Emission 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 name / English name / replacement relationship

• Method number: SH/T 0749-2004
• Chinese full name: Determination of Additive Elements Content in Lubricating Oils and Additives (Inductively Coupled Plasma Atomic Emission Spectrometry)
• English name: Standard test method for determination of additive elements in both lubricating oils and additives by inductively coupled plasma atomic emission spectrometry
• Replacement relationship: not provided in the available source (the foreword does not mention replacement of any standard)
• Publication/implementation: published on 2004-04-09, implemented on 2004-09-01
• Publishing unit: National Development and Reform Commission of the People's Republic of China
• Responsible committee: Sinopec Research Institute of Petroleum Processing
• Drafting unit: Sinopec Research Institute of Petroleum Processing
• Main drafters: Wang Xia, Yan Jingjie

2. Scope of application and non-applicability

• 1.1 This standard is applicable to the determination of the content of common additive elements such as calcium, zinc, magnesium, sulfur, phosphorus, barium, boron, lithium, and cobalt in lubricating oils and additives.
• The content ranges listed in the precision table are the element content ranges examined in the statistical test; for other content ranges, this standard has not examined their precision.
• 1.2 This standard does not propose recommendations for all safety issues involved; users should establish appropriate safety precautions and determine appropriate regulations before use.
• Non-applicable scope: not provided in the available source as an explicit list.

3. Method principle

The sample is pretreated in a pressure digestion bomb with hydrogen peroxide and nitric acid to form an acidic aqueous solution, and the element content in the sample solution is determined with an inductively coupled plasma atomic emission spectrometer (ICP-AES). (Chapter 3 Method summary)

4. Reagents and materials (purity / preparation)

• 6.1 Reagent purity: unless otherwise specified, analytical grade reagents should be used. If reagents of other grades are used, their purity shall not reduce the accuracy of the determination.
• 6.2 Nitric acid: guaranteed reagent grade.
• 6.3 Hydrochloric acid: guaranteed reagent grade.
• 6.4 Hydrogen peroxide (30%).
• 6.5 Water: meets the requirements for grade three water in GB/T 6682.

7.1 Preparation of standard stock solutions (Table 1)

Prepare or purchase single-element standard stock solutions of 1000mg/L calcium, zinc, magnesium, sulfur, phosphorus, barium, boron, lithium, and cobalt according to the standard substance preparation method. The preparation methods provided in Table 1 are for reference only; the reagent purity in the table is spectroscopically pure or not lower than 99.9%. For compounds with lower reagent purity or that cannot be dried, after preparing the solution, it should be calibrated against a national standard solution.

(Note: The chemical formulas in Table 1 such as CaCO, Z0, MgO, BaCh, B0s, Co0, etc. are source-text extraction noise, have been restored according to common chemical formulas, requires confirmation against the source standard (source-text extraction).)

7.2 Mixed standard solution (100mg/L)

Take each of the 5mL calcium, zinc, magnesium, phosphorus, barium, boron, lithium, and cobalt standard stock solutions into one 50mL volumetric flask, and dilute with water to the mark.

7.3 Mixed standard working curve solutions (0mg/L, 5mg/L, 10mg/L and 20mg/L)

Pipette 0mL, 2.5mL, 5mL, 10mL of the mixed standard solution respectively into four 50mL volumetric flasks, add 5mL nitric acid to each, and dilute with water to the mark.

7.4 Sulfur standard working curve solutions (20mg/L, 50mg/L and 200mg/L)

Pipette 1mL, 2.5mL, 10mL of the sulfur standard stock solution respectively into three 50mL volumetric flasks, add 5mL nitric acid to each, and dilute with water to the mark.

Note: The concentrations of the above standard working curve solutions are for user reference only; users may make appropriate adjustments according to the actual conditions of the instrument and samples.

5. Instruments and equipment

• 5.1 Inductively coupled plasma atomic emission spectrometer: either a sequential scanning or a full-spectrum direct-reading inductively coupled plasma atomic emission spectrometer may be used. When determining sulfur and phosphorus, spectral lines below 190nm are required, and the instrument is required to have an optical path vacuum or purge function.
• 5.2 Pressure digestion bomb: capacity 50mL, outer cylinder made of 1Cr18Ni9Ti stainless steel, inner cup made of polytetrafluoroethylene, recommended use temperature less than 180℃, maximum load-bearing pressure 5MPa. The structural schematic diagram of the pressure digestion bomb is shown in Figure 1.
• 5.3 Oven: constant temperature 150℃±5℃.
• 5.4 Balance: readability 0.1mg.
• 5.5 Volumetric flasks: 25mL, 50mL.
• 5.6 Pipettes: 1mL, 5mL, 10mL.

Figure 1 Labels for the structural schematic diagram of the pressure digestion bomb: 1— bolt; 2— inner cup lid; 3— outer cylinder cover body; 4— inner cup body; 5— gasket; 6— outer cylinder body; 7— inner cup upper pressure cover; 8— inner cup lower support base. (The correspondence between numbers and names requires confirmation against the source standard (source-text extraction))

6. Recommended operating conditions

• Instrument adjustment: adjust the instrument parameters according to the instructions in the instrument operation manual, adjust the nebulizer flow rate and sample introduction speed, etc., ignite, and check whether the instrument is working normally.
• The wavelengths used for the determination elements are shown in Table 2 (Note: the wavelengths provided in Table 2 are for user reference only; no obvious interference was found when using the provided wavelengths to determine the elements in this method. Users may select other suitable wavelengths for determination based on the instrument used and the interference of elements in the sample).

Table 2 Determination elements and wavelength table

7. Sampling and sample preparation

• Sampling: sampling should be carried out in accordance with the requirements of GB/T 4756. (Chapter 8)
• Sample pretreatment (9.1): accurately weigh 0.1–0.5g of sample (to the nearest 0.1mg) into a polytetrafluoroethylene cup, add nitric acid 3mL, 30% hydrogen peroxide 3mL, place the polytetrafluoroethylene cup into the outer cylinder of the pressure digestion bomb, tighten the bolt, place in an oven at 150℃±5℃, and keep at constant temperature for 5–6h. Cut off the power, and allow the pressure digestion bomb to cool naturally to room temperature in the oven. Take the pressure digestion bomb out of the oven, pour the treated sample into a 25mL volumetric flask, wash the polytetrafluoroethylene cup with water at least 3 times, pour all the washings into the volumetric flask, and dilute with water to the mark.
• Warning: Before the pressure digestion bomb has cooled to room temperature, the temperature and internal pressure are both high; it must not be taken out of the oven or have the bolt unscrewed, otherwise it may cause scalding or acid burns.

8. Analysis steps

• 9.1 Sample pretreatment: see Section 7.
• 9.2 Instrument adjustment: adjust the instrument parameters according to the instructions in the instrument operation manual, adjust the nebulizer flow rate and sample introduction speed, etc., ignite, and check whether the instrument is working normally. The wavelengths used for the determination elements are shown in Table 2.
• 9.3 Aspirate the blank and standard working curve solutions in sequence to establish the standard working curve.
• 9.4 Aspirate the sample solution to be tested to obtain the determination result.

9. Qualitative and quantitative determination and calculation formula

The content C% (mass fraction) of each element in the sample is calculated according to formula (1), to the nearest 0.01%:

C = (S × V) / (1000 × m) ………………(1)

Where:

• C—— content of each element in the sample, % (mass fraction);
• V—— dilution volume, mL;
• S—— element concentration in the sample solution read from the standard working curve, mg/L;
• m—— mass of sample weighed, g.

(Note: the original formula source-text extraction is displayed as "Y×D / 1000m"; combined with the symbol explanations it should be S×V/(1000×m), requires confirmation against the source standard (source-text extraction).)

10. Precision

Judge the reliability of the test results according to the following provisions (95% confidence level). Through inter-laboratory statistical investigation, the precision of the method calculated according to GB/T 6683 is as follows.

11.1.1 Repeatability

The difference between two test results obtained by the same operator using the same instrument under constant operating conditions on the same sample for continuous determinations shall not exceed the values listed in Table 3.

Table 3 Repeatability

Note: X—— average of the two results, % (mass fraction).

11.1.2 Reproducibility

The difference between two independent test results obtained by different operators working in different laboratories on the same sample shall not exceed the values listed in Table 4.

Table 4 Reproducibility

Note: X—— average of the two results, % (mass fraction).

11.2 Bias

Because there is no suitable reference material, the bias of this method cannot be determined.

11. Report

not provided in the available source (the main text of the standard does not have a "Report" section).

12. Normative references

• GB/T 4756 Petroleum liquids—Manual sampling (GB/T 4756—1998, ISO 3170:1988, MOD)
• GB/T 6682 Specifications and test methods for water used in analytical laboratories (GB/T 6682—1992, ISO 3696:1987, NEQ)
• GB/T 6683 Determination of precision data for test methods of petroleum products (GB/T 6683—1997, ISO 4259:1992, NEQ)

(Note: in the original source-text extraction, GB/T was misrecognized as CB/T; it has been restored according to the standard number convention, requires confirmation against the source standard (source-text extraction).)

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 Q&A reference