SH/T 0120-1992 Determination of Phenol Content in Phenol-Refined Lubricating Oils

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Card type: Test method

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

• Standard number: SH/T 0120-92
• Full title: Determination of Phenol Content in Phenol-Refined Lubricating Oils
• English name: not provided in the available source
• Replacement relationship: From the date of implementation of this standard, the original national standard GB 504-77(88) "Determination of Phenol Content in Phenol-Refined Lubricating Oils" is void.
• Reference adoption: Former Soviet national standard GOST 1057-59 "Method for Determination of Phenol and Cresol Content in Selective Refining Lubricating Oils" (the source text marks it as "reference adoption"; standard number source-text extraction is "'0U 1057-59", requires confirmation against the source standard (source-text extraction)).
• Approval/implementation: approved by China Petrochemical Corporation 1992-05-20, implemented on 1992-05-20.

2. Scope of application and non-applicability

• This standard specifies a method for determining the phenol content in phenol-refined lubricating oils.
• This standard applies to phenol-refined lubricating oils that do not contain additives.
• Non-applicability: no explicit non-applicability clauses are provided in the available source.

3. Method principle

Bromine released by adding acid to a potassium bromate-potassium bromide standard solution is used as the brominating agent to brominate the aqueous solution of phenol extracted from the sample. The excess bromine is then determined by iodometric titration of the liberated free iodine, and the phenol content is calculated from the volume of sodium thiosulfate standard titration solution consumed.

4. Reagents and materials (purity / preparation)

• 4.1 Benzene: analytical reagent.
• 4.2 95% Ethanol: analytical reagent.
• 4.3 Potassium bromide: analytical reagent.
• 4.4 Potassium bromate: analytical reagent. Prepare c(1/6 KBrO3)=0.1 mol/L potassium bromate-potassium bromide standard solution. (The concentration expression source-text extraction in the source text is "KB703)[unreadable sign]0.1 mol/L", requires confirmation against the source standard (source-text extraction))
• 4.5 Hydrochloric acid: chemical reagent.
• 4.6 Potassium iodide: chemical reagent, prepare a saturated potassium iodide solution.
• 4.7 Sodium thiosulfate: analytical reagent, prepare c(Na2S2O3)=0.1 mol/L sodium thiosulfate standard titration solution. (The source text source-text extraction is "(Na2[unreadable character]03)[unreadable sign]0.1 mol/L", requires confirmation against the source standard (source-text extraction))
• 4.8 Soluble starch: prepare 10g/L starch indicator solution.
• Materials (3.2): the solvent is 50～100℃ straight-run gasoline; the gasoline should not contain substances that can react with bromides (or it may be replaced by 60～90℃ analytical reagent petroleum ether); the solvent must be subjected to the blank test specified in this standard.

5. Apparatus and equipment

• 3.1.1 Volumetric flask: 250, 1000mL.
• 3.1.2 Graduated cylinder: 10, 100mL.
• 3.1.3 Pipette: 100mL.
• 3.1.4 Burette: 25, 50mL.
• 3.1.5 Long-neck separatory funnel: 500mL.
• 3.1.6 Iodine flask: 500mL.
• 3.1.7 Drying oven.
• 3.1.8 Water bath.

6. Recommended operating conditions

• Extraction water temperature: 70～80℃.
• Cooling temperature of phenol-containing solution: 20℃±3℃.
• Time kept in ice water for bromination reaction: 15min.
• Standing time after adding saturated potassium iodide: 2min.
• Heating before weighing oil samples with pour point above room temperature: not higher than 60℃ water bath.
• If separation is slow, it may be rotated and shaken or heated (70～80℃).

7. Sampling and sample preparation

• Place the sample into a bottle; the sample amount should not exceed three-quarters of the bottle's internal volume.
• Before weighing the sample, shake 5min first; oil products with a pour point above room temperature should be heated in a water bath not higher than 60℃.
• Weigh 100g sample, accurate to 0.01g, and place it into a separatory funnel.
• Note: for samples with phenol content above 0.1%(m/m), the weighed amount is below 10g.

8. Analytical procedure

• 6.1 Weigh 100g sample, accurate to 0.01g, and place it into a separatory funnel. (Note: for samples with phenol content above 0.1%(m/m), the weighed amount is below 10g)
• 6.2 Dissolve the sample with 100mL solvent; if straight-run gasoline or petroleum ether does not dissolve it well, the sample must be dissolved with benzene in a water bath.
• 6.3 Add 70～80℃ distilled water 70mL to the separatory funnel containing the sample, shake for 1min, and let stand to separate into layers; if the separation rate is very slow, rotation and shaking or heating may be used (70～80℃).
• 6.4 Put the lower aqueous solution into a 250mL volumetric flask, wash the upper solution in the separatory funnel with 70～80℃ distilled water 70mL, for a total of three washes, and combine the washings into the volumetric flask; cool this phenol-containing solution to 20℃±3℃, add cold distilled water to the 250mL mark, and mix the solution well.
• 6.5 Use a pipette to draw 100mL solution from the volumetric flask into an iodine flask, add 25mL c(1/6 KBrO3)=0.1mol/L potassium bromate-potassium bromide standard solution, then add 5mL hydrochloric acid, place the iodine flask in ice water, and keep for 15min.
• 6.6 Add 2mL saturated potassium iodide solution to the above iodine flask; after 2min, titrate with c(Na2S2O3)=0.1mol/L sodium thiosulfate standard titration solution; when the solution becomes pale yellow, add 1mL freshly prepared 10g/L starch indicator solution, and continue titration (this process should be short and the number of drops consumed should be small) until the blue color disappears.
• 6.7 Blank test: to a clean, dry iodine flask, add 25mL c(1/6 KBrO3)=0.1mol/L potassium bromate-potassium bromide standard solution, 100mL distilled water, and 5mL hydrochloric acid; stopper the flask, shake, keep in ice water for 15min, and then operate according to clause 6.6.
• Correction test: if the solvent used to dissolve the sample or the sample itself before phenol refining can undergo bromination reaction, take a corresponding mass of the sample before phenol refining, dissolve it with the corresponding solvent (straight-run gasoline or petroleum ether, benzene) 100mL, then carry out the test according to clauses 6.4～6.7 and make the corresponding correction.

9. Qualitative and quantitative determination and calculation formula

The phenol content X〔%(m/m)〕 in the sample is calculated according to the following formula:

X = (V - V1) × c × 0.01568 × 2.5 × 100 / m

Where:

• V —— the volume of sodium thiosulfate standard titration solution consumed in titrating the blank test, mL;
• V1 —— the volume of sodium thiosulfate standard titration solution consumed in titrating the sample, mL;
• 0.01568 —— the mass of phenol, expressed in grams, equivalent to 1.00mL sodium thiosulfate standard titration solution〔c(Na2S2O3)=1.000mol/L〕;
• 2.5 —— the ratio of the total volume of the phenol-containing solution (250mL) to the volume used for titration (100mL);
• m —— the mass of the sample, g;
• c —— the actual concentration of the sodium thiosulfate standard titration solution, mol/L.

(The formula source-text extraction in the source text is "X=(1[unreadable characters]x 0.01568 xZ.5 x(、100", requires confirmation against the source standard (source-text extraction))

10. Precision

Repeatability: the difference between two results obtained by repeated determination by the same operator should not exceed the following values.

(The table source-text extraction in the source text is "< 0.01 ,0.01"; the lower-limit symbol of the second range requires confirmation against the source standard (source-text extraction))

11. Report

• 9.1 Take the arithmetic mean of two results from repeated determination as the determination result.
• 9.2 When the phenol content is below 0.005%(m/m), it is considered to contain no phenol.

12. Referenced documents

• Original national standard GB 504-77(88) "Determination of Phenol Content in Phenol-Refined Lubricating Oils" (void).
• Former Soviet national standard GOST 1057-59 "Method for Determination of Phenol and Cresol Content in Selective Refining Lubricating Oils" (reference adoption; standard number requires confirmation against the source standard (source-text extraction)).
• Other referenced documents: not provided in the available source.

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