NB/SH/T 0812-2010 Determination of 2- furfural and related components in mineral insulating oil

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Card type: Test method

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

• Standard number: NB/SH/T 0812—2010 (in source-text extraction there appear multiple noisy forms such as NB/SII/T, NB/SH/T, NB/S[unreadable character]T, etc.; the authoritative form is NB/SH/T 0812—2010)
• Chinese title: Determination of 2- furfural and related components in mineral insulating oil
• English title: Mineral insulating oils—Method for the determination of 2-furfural and (the original English title is incomplete; the latter part requires confirmation against the source standard (source-text extraction))
• Adoption relationship: modified adoption of IEC 61198:1993 (MOD)
• Replacement relationship: this standard is first issued (no replaced standard number is not provided in the available source)
• Publication/implementation: published on 2010-05-01, implemented on 2010-10-01 (in source-text extraction, “2010-0.5-01 published” and “2010-10.01 implemented”)
• Proposed by/under the jurisdiction of: proposed by China Petrochemical Corporation; under the jurisdiction of the Petrochemical Research Institute of China Petroleum & Chemical Corporation
• Drafting organization: Karamay Lubricating Oil Research Institute of PetroChina Company Limited
• Main drafters: Liu Ying, Hou Yudong, Zhang Bo, Shang Baozhu, Wang Jinhui

2. Scope of application and non-applicability

• 1.1 This standard specifies a method for the determination of 2- furfural and related components in insulating oil by high performance liquid chromatography.
• 1.2 This standard is applicable to the detection of furfural content in used mineral insulating oil, and may also be applicable to new mineral insulating oil.
• Not applicable: the original text does not explicitly list non-applicable clauses. This standard does not adopt the solid-liquid extraction content of method B in IEC 61198:1993 and its related annex A and figure 1 content (see the foreword).

3. Method principle

• Chapter 3 Method summary: a liquid-liquid extraction method is used to extract furan derivatives from insulating oil, and then the extract is introduced into a high performance liquid chromatograph (HPLC) for analysis.
• Chapter 4 Significance and use:
  • 4.1 Degradation of cellulosic materials in the solid insulation of oil-filled electrical equipment generates corresponding decomposition products, such as sugars and furan derivatives.
  • 4.2 Most furan derivatives are adsorbed on the insulating paper in electrical equipment and are only slightly soluble in oil; their presence can serve as a basis for inspection of in-service equipment and as supplementary information for dissolved gas analysis.

4. Reagents and materials (purity / preparation)

• 6.1 Acetonitrile: chromatographic grade.
• Other reagents (such as methanol, water, acetic acid, reference materials, etc.): the original text in this paragraph source-text extraction is severely incomplete, with only fragments such as “hydroxymethyl[unreadable separator]2/[garbled characters]■q”, “furfuryl alcohol (2[unreadable character],)”, “furfural ([unreadable character]1^C,k/”, “external light spectrum”, “standard [unreadable character]”, “standard solution” visible; the specific names, purity, standard solution preparation concentrations and steps require confirmation against the source standard (source-text extraction), and complete content is not provided in the available source.
• Mobile phase: 60% (volume fraction) water—40% (volume fraction) methanol or acetonitrile (source-text extraction is “6()[garbled characters]—qk[garbled volume-fraction wording]); 20%～40% methanol or acetonitrile (”; the specific ratio requires confirmation against the source standard (source-text extraction)).
• Note: under certain conditions, adding a small amount of acetic acid (about 1%) can improve the separation of more polar components; gradient elution can improve the separation effect (the original text of this note source-text extraction is incomplete and requires confirmation against the source standard (source-text extraction)).

5. Apparatus and equipment

• 5.1 High performance liquid chromatograph
  • 5.1.1 Pumping system: capable of delivering (or using) at least two solvents.
  • 5.1.2 Injection device: suitable for injecting 10 μL～20 μL, and a suitable precision syringe (capacity 50 μL～250 μL).
  • 5.1.3 Reversed-phase C8 column or C18 column.
  • 5.1.4 Guard column packed with the same material as the analytical column (optional).
  • 5.1.5 Ultraviolet (UV) detector; a diode array UV detector is recommended.
  • 5.1.6 Data acquisition system (chromatography workstation, integrator, or recorder are all acceptable).
• 5.2 Beaker or conical flask.
• 5.3 Volumetric flask.
• 5.4 Analytical balance: sensitivity 0.1 mg.
• 5.5 25 mL stoppered graduated cylinder or test tube.
• 5.6 5 mL dropper.
• 5.7 Mechanical shaker.

6. Recommended operating conditions

• Detection wavelength: 276 nm (Figure A.2 is labeled “wavelength: 276nm”, Figure A.2 is titled “typical chromatogram (220nm and 276nm)”, and 220 nm also appears; the specific quantitative wavelength requires confirmation against the source standard (source-text extraction)).
• Mobile phase: 60% water—40% methanol or acetonitrile (volume fraction, requires confirmation against the source standard (source-text extraction)).
• Flow rate: the original text is “flow rate: 0”; the value is incomplete and requires confirmation against the source standard (source-text extraction).
• Column temperature, injection volume, gradient program, etc.: not provided in the available source (or source-text extraction is incomplete).
• Note: appropriate adjustments are needed according to instrument characteristics and laboratory conditions (the original text of this sentence source-text extraction is incomplete and requires confirmation against the source standard (source-text extraction)).

7. Sampling and sample preparation

• 9.1 Extraction of components to be analyzed: take about 20 mL of sample, accurate to 0. (the value is incomplete and requires confirmation against the source standard (source-text extraction)); add acetonitrile and inject into a 25 mL graduated cylinder or test tube with a ground stopper; shake the sample on a mechanical shaker for at least 2 min; allow the sample to stand until the acetonitrile and oil phases completely separate.
• Sampling references: GB/T 4756 Manual sampling of petroleum liquids; GB/T 7597 Sampling method for power oils (transformer oil, turbine oil).
• Other sample preparation details: the original text source-text extraction is incomplete and requires confirmation against the source standard (source-text extraction).

8. Analytical procedure

• 9.1 Extraction: see Section 7.
• 9.2 Use (standard solution) single-point (external standard method)... (the original text is incomplete and requires confirmation against the source standard (source-text extraction)).
• 9.3 According to clause 9.2... (the original text is incomplete and requires confirmation against the source standard (source-text extraction)).
• Subsequent steps of Chapter 9 (injection, chromatographic acquisition, peak area/peak height measurement, etc.): the original text source-text extraction is severely incomplete, with only fragments such as “detector response (peak area or peak height)” and “peak area [garbled trailing text]” visible; requires confirmation against the source standard (source-text extraction).

9. Qualitative and quantitative determination and calculation formulas

• Quantification method: single-point external standard method (the words “single point” appear in the original text; the specific formula source-text extraction is incomplete and requires confirmation against the source standard (source-text extraction)).
• Calculation formula: in Chapter 8 (or Chapter 9) of the original text, “C—— standard solution...” and “R1—— standard solution...” appear; the main body of the formula is missing and requires confirmation against the source standard (source-text extraction).
• Result unit: mg/kg (both the report and the lower detection limit are expressed in mg/kg).
• Report concentration accurate to 0.0 (the value is incomplete and requires confirmation against the source standard (source-text extraction)).

10. Precision

• Judge the reliability of the determination results according to the following provisions (95% confidence level).
• 13.1 Repeatability: the difference between two results obtained by the same operator using the same instrument for repeated determination of the same sample shall not exceed the value in Table 1.
  • Table 1 Repeatability
    • Concentration of furan derivative components <1.0 mg/kg: repeatability 0.1X (source-text extraction is “OlX”, requires confirmation against the source standard (source-text extraction))
    • Concentration of furan derivative components ≥1.0 mg/kg: repeatability 0.05X
    • Note: X is the average value of the determination results.
    • Note: in aged oils, the above values may not be achieved because of interference from aging products.
• 13.2 Reproducibility: the difference between two results obtained by different operators in two laboratories using different instruments for determination of the same sample shall not exceed the value in Table 2.
  • Table 2 Reproducibility
    • Concentration of furan derivative components <1.0 mg/kg: reproducibility 0.15X
    • Concentration of furan derivative components ≥1.0 mg/kg: reproducibility 0.1X
    • Note: X is the average value of the determination results.

11. Report

• Chapter 11 The report shall include:
  • a) This standard (number);
  • b) The sample (identification and other information; the original text is incomplete and requires confirmation against the source standard (source-text extraction));
  • c) According to mg/kg (the determination result expressed; the original text is incomplete and requires confirmation against the source standard (source-text extraction));
  • d) Detector response.
• Report concentration accurate to 0.0 (the value is incomplete and requires confirmation against the source standard (source-text extraction)).

12. Normative references

• GB/T 4756 Manual sampling of petroleum liquids (GB/T 4756—1998, eqv ISO 3170:1988)
• GB/T 6682 Specifications and test methods for water for analytical laboratory use (GB/T 6682—1992, neq ISO 3696:1987)
• GB/T 7597 Sampling method for power oils (transformer oil, turbine oil)
• IEC 61198:1993 Determination of 2- furfural and related components in mineral insulating oil (English version) (modified adoption)
• Annex A (informative annex) Typical ultraviolet spectra and chromatograms
• Annex B (informative annex) Comparison table of clause numbers of this standard and IEC 61198:1993

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