GB/T 380-1977 Determination of sulfur content in petroleum products (Lamp combustion method)

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: GB 380-77 (the main text title contains "GB 880-77", suspected to be a misrecognition of source-text extraction, requires confirmation against the source standard (source-text extraction); the file name and the main text clause page header are both GB 380-77)
• Chinese name: Determination of sulfur content in petroleum products (Lamp combustion method)
• English name: Petroleum products — Determination of sulphur — Lamp method (the original text reads "Petroleim products-Determinatlon of sulphur-Lemp method", the spelling is suspected to be source-text extraction noise, requires confirmation against the source standard (source-text extraction))
• Replacement relationship: the source transcription gives GB 380-84, which conflicts with the chronology. The superseded edition is unverified; it has not been inferred from the year numbers.
• Confirmation information: the original text is marked "(1988 year confirmed)"
• Publication/implementation: issued by the National Bureau of Standards and Metrology 1977-07-16, implemented on 1977-10-01

2. Scope of application and non-applicability

• Applicable to the determination of the sulfur content of light petroleum products (gasoline, kerosene, diesel, etc.) with a Reid vapor pressure not higher than 600 millimeters of mercury.
• Not applicable: no explicit non-applicability clause is provided in the available source.

3. Method principle

The petroleum product is burned in a lamp, the sulfur dioxide generated is absorbed with an aqueous sodium carbonate solution, and it is determined by volumetric analysis.

4. Reagents and materials (purity / preparation)

• 3.1 Sodium carbonate: analytical reagent, prepared as a 0.3% aqueous solution.
• 3.2 Hydrochloric acid: analytical reagent, prepared as a 0.05N standard solution.
• 3.3 Indicator: prepare in advance a 0.2% bromocresol green ethanol solution and a 0.2% methyl red ethanol solution. When in use, mix 5 parts by volume of the bromocresol green solution and 1 parts by volume of the methyl red solution (red in acid, green in alkali).
• 3.4 95% Ethanol: analytical reagent.
• 3.5 Standard n-heptane.
• 3.6 Gasoline: boiling range 80~120℃, sulfur content not exceeding 0.005%.
• 3.7 Petroleum ether: 60~90℃, chemically pure.
• Other materials: cotton wick (with wick tube); glass beads: diameter 5–6 millimeters (or short glass rods, length 8–10 millimeters, diameter 5~6 millimeters).

5. Apparatus and equipment

• 2.1 Petroleum product sulfur content tester (see figure). Its dimensions are shown in Appendix A, Figure A1 and Figure A2.
• 2.2 Suction filter flask: 500~1000 milliliters.
• 2.3 Burette: 25 milliliters.
• 2.4 Pipette: 2, 5 and 10 milliliters.
• 2.5 Wash bottle.
• 2.6 Water jet pump or vacuum pump.
• 2.7 Glass beads: diameter 5–6 millimeters (or short glass rods, length 8–10 millimeters, diameter 5~6 millimeters).
• 2.8 Cotton wick: with wick tube.
• Apparatus composition (figure caption): 1— absorber; 2— droplet collector; 3— flue; 4— combustion lamp with wick; 5— wick.
• Appendix A Figure A2 figure caption: 1— lamp base; 2— wick sleeve.

6. Recommended operating conditions

• The determination of sulfur content must be carried out in a room with air flow, but violent ventilation should be avoided (4.1).
• Flame height: after ignition, adjust the flame height to 5–6 millimeters (4.3.1); during the test, the flame height of each lamp must be adjusted to 6–8 millimeters (5.1).
• Position of the edge of the wick tube: place it below each flue so that the edge of the wick tube is not higher than 8 millimeters below the lower edge of the flue (5.1).
• The lamp must be lit with a sulfur-free flame, such as an alcohol lamp flame (matches must not be used to light the lamp) (5.1).
• The air suction speed in the absorber must be kept uniform and adjusted with a screw clamp so that the flame does not produce black smoke (5.1).
• After the sample has burned out, extinguish the lamp, cover it with the lamp cover, and after 3~5 minutes, close the water jet pump (5.3, the original text reads "＄~5 minutes", suspected to be source-text extraction noise, requires confirmation against the source standard (source-text extraction)).

7. Sampling and sample preparation

• 4.3 Load the sample into the lamp according to the following procedure:
• 4.3.1 For petroleum products that burn without smoke in the lamp, inject the following amounts into a clean, dry lamp (no need to weigh in advance): for low-boiling products with trace sulfur (sulfur content below 0.05%) (such as aviation gasoline), the injection amount is 4–5 milliliters; for products with sulfur content above 0.05% and high-boiling products (such as gasoline, kerosene, etc.), the injection amount is 1.5–3 milliliters (the specific amount depends on the sulfur content). Close the lamp with a wick tube threaded with a wick. The lower end of the wick is placed around the bottom of the lamp. After the petroleum product has soaked the wick, cut off the wick outside the wick tube so that it is flush with the upper edge of the wick tube. Then light the lamp, adjust the flame so that its height is 5~6 millimeters. Then extinguish the flame, cover the lamp with the lamp cover, and weigh on an analytical balance to the nearest 0.0004 grams. In the same way, load the sample into a second lamp, and load standard n-heptane or 95% ethanol or gasoline (no need to weigh) into a third lamp for the blank test.
• 4.3.2 For petroleum products that burn alone in the lamp and produce dense smoke (high-temperature cracked products containing large amounts of aromatic hydrocarbons or unsaturated hydrocarbons, catalytic cracking products, etc.) and high-boiling petroleum products (such as diesel), take 1–2 milliliters and inject into a clean, dry lamp that has been weighed beforehand together with the wick and lamp cover (to the nearest 0.0004 grams). Then inject standard n-heptane or 95% ethanol or gasoline into the lamp to make a ratio of 1:1 or 2:1, and if necessary a ratio of 3:1 (volume ratio), so that the mixed liquid burns in the lamp with a flame that does not produce smoke. The total volume of the mixed liquid composed of the sample and the injected standard n-heptane or 95% ethanol or gasoline is 4–5 milliliters. In the same way, load the sample into a second lamp, and load standard n-heptane or 95% ethanol or gasoline (no need to weigh) into a third lamp for the blank test.
• 4.2 Before installing the apparatus, carefully wash the absorber, droplet collector and flue with distilled water. Wash the lamp and wick with petroleum ether and dry them.

8. Analysis procedure

• 4.4 Connect the suction filter flask to the water jet pump or vacuum pump with a rubber tube, and insert one end of the glass three-way stopcock through the rubber stopper into the neck of the flask, and connect the other two ends to the absorber with rubber tubes. The third set of absorbers is also connected to the rubber stopper of the suction filter flask with a rubber tube and a glass bent tube, so that three sets of apparatus can be tested simultaneously. Into the large container of absorber 1, place glass beads or glass rods carefully washed with distilled water to a height of about 2/3. And accurately inject 0.3% sodium carbonate solution 10 milliliters with a pipette, and inject distilled water 10 milliliters with a graduated cylinder. Put screw clamps on the rubber tube between the suction filter flask and the suction pump and between the droplet collector 2 and the three-way stopcock.
• 5.1 After the apparatus is installed, start the water jet pump so that air passes uniformly and gently through all absorbers. Then remove the lamp cover from lamp 4, light all the lamps, and place them below each flue 3 so that the edge of the wick tube is not higher than 8 millimeters below the lower edge of the flue. When lighting the lamp, a sulfur-free flame must be used, such as an alcohol lamp flame (matches must not be used to light the lamp). The flame height of each lamp must be adjusted to 6~8 millimeters. When adjusting the flame height, use a needle to poke the inner wick. In all absorbers, the air suction speed must be kept uniform and adjusted with a screw clamp so that the flame does not produce black smoke.
• 5.2 Make the sample in each lamp burn completely. If the sample has been diluted with standard n-heptane or 95% ethanol or gasoline, after it has burned out, inject another 1~2 milliliters of standard n-heptane or 95% ethanol or gasoline into the lamp and let it all burn out.
• 5.3 After the sample has burned out, extinguish the lamp, cover it with the lamp cover, and after 3~5 minutes, close the water jet pump.
• 5.4 Disassemble the apparatus and spray-wash the droplet collector, flue and upper part of the absorber with distilled water from a wash bottle. Collect the washing distilled water in the absorber in which sulfur dioxide was absorbed with 0.3% sodium carbonate solution. Add 1~2 drops of indicator to the absorber. If the solution in the absorber is red at this time, the test is considered invalid and the test should be repeated. At this time, the amount of sample burned should be reduced.
• 5.5 After adding the indicator, titrate with 0.05N hydrochloric acid solution. In order to stir the solution during titration, connect a rubber tube to the glass tube of the absorber, and use a rubber bulb or pump to aerate or evacuate the solution for stirring. First titrate the blank test solution (the absorption liquid of the substances generated after combustion of standard n-heptane or 95% ethanol or gasoline) until it turns red, as the blank test. Then titrate each solution containing the combustion products of the sample. When the solution shows the same red color as that shown by the already titrated blank test, the titration endpoint has been reached.
• Note: Separately titrate with 0.3% sodium carbonate solution and compare with the blank test. If the difference between the volumes of 0.05N hydrochloric acid solution consumed in these two titrations exceeds 0.05 milliliters, it proves that the air has been contaminated with sulfur. In this case, the test is invalid, and another determination should be made after the laboratory has been ventilated.
• 5.6 The amount of sample burned is determined as follows:
  • 5.6.1 When burning an undiluted sample, after combustion is complete, place the lamp on an analytical balance and weigh it (to the nearest 0.0004 grams). And calculate the difference between the weight of the lamp containing the sample before the test and the weight of the lamp after combustion, as the amount of sample burned.
  • 5.6.2 When burning a diluted sample, calculate the difference between the weight of the lamp containing the sample and the weight of a clean, dry lamp without sample, as the amount of sample burned.

9. Qualitative and quantitative determination and calculation formula

The sulfur content X (%) of the sample is calculated according to the following formula:

X = [(V - V₁) × K × 0.0008 × 100] / G

Where:

• V—— volume of hydrochloric acid solution consumed in titrating the blank test solution, milliliters;
• V₁——volume of hydrochloric acid solution consumed in titrating the solution absorbing the combustion products of the sample, milliliters;
• K—— correction factor for conversion to 0.05N hydrochloric acid solution (is the ratio of the actual equivalent concentration of hydrochloric acid to 0.05N);
• 0.0008—— sulfur content equivalent to unit volume of 0.05N hydrochloric acid solution, grams per milliliter;
• G—— combustion amount of the sample, grams.

(The original formula is typeset as "X=LV-YLK×0.0098x100", in which "0.0098" and "0.0008" are inconsistent, suspected to be source-text extraction noise, requires confirmation against the source standard (source-text extraction); the main text explanation is 0.0008 grams per milliliter.)

10. Precision

The difference between two repeated determination results shall not exceed the following values:

(The original table header is "Sulfur content, % / <0.1 / >0.1 / Permissible difference / 0.006% / 6% of the minimum measured value", source-text extraction typesetting is garbled, requires confirmation against the source standard (source-text extraction).)

11. Report

Take the arithmetic mean of two repeated determination results as the sulfur content of the sample.

12. Referenced documents

No independent "Referenced documents" section is provided in the available source. Test method standard numbers mentioned in the text: 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 Q&A reference