Regarding the issue of water content in the solvent?

This post was last edited by zbx on 2009-11-8 03:07. Determine whether the water level is high; check if it is free water. If the level is not high and the water is miscible with the oil, chromatographic analysis can be used, with a thermal conductivity cell as the detector, or a Karl Fischer titrator can also be employed. If the water level is high and there is free water present, then the petroleum water determination method (azeotropic distillation) should be used

Water can be measured using a Karl Fischer titrator; a hydrogen flame detector used in chromatography cannot detect water. By performing these two tests, it is possible to determine the components of solvent oil No. 6

You can check the relevant standards; a TCD detector should be able to conduct the detection

This post was last edited by qugd on 2009-11-9 at 11:28. The determination of water content in oil is best carried out using the Karl Fischer method, as the solubility of water in oil is limited; gas chromatography has low sensitivity for detecting water, and it also requires specific carrier gases and columns, resulting in poor repeatability and accuracy. Multiple national and authoritative standard analysis methods use the Karl Fischer method for moisture detection, which offers excellent sensitivity and accuracy. In the product standards for petroleum products, applicable methods for determining moisture content are generally specified, which can be used as a reference. For the analysis of water in oils, it can be related to product quality and trade transactions; using methods that are not recognized by the other party may lead to problems. This is something that those responsible for analysis and testing, especially quality control personnel, need to keep in mind, as failing to follow the rules can sometimes result in penalties. If the product standards do not specify a particular method, it is reasonable to have the relevant parties agree on an accepted testing method; one should not make decisions based on personal will or imagination. Additionally, solvent oil No. 6 is used quite frequently in the extraction of edible oils, so stricter standards are required. English name: Solvent-extracted oil No.6; Alternative names: 6th solvent oil, soybean extract solvent oil. Product properties: It is a colorless and transparent liquid that is a mixture of various lower alkanes. The product fraction range is wider than that of industrial hexane, and it possesses properties similar to those of industrial hexane. It is miscible with most liquid fats and oils other than castor oil, and can dissolve lower fatty acids. Production method: It is primarily made from catalytic reforming raffinate oil, through refining and distillation. Primary uses: It is mainly used as a solvent for spices and the extraction of vegetable oils; it can also be used as a solvent in the synthesis of rubber and as a cleaning solvent for precision parts. Product standard: GB 16629-96. Packaging and storage and transportation: Follow SH 0164. When used as an extraction solvent for vegetable oils, it should be stored in dedicated tanks, transported via dedicated pipelines, and carried in dedicated vehicles; it must not be mixed with other types of oils. Store in a cool and well-ventilated area, taking care to prevent fire, explosion, and static electricity. Flame explosion hazard and toxicity: Highly volatile, flammable, and explosive. Inhalation of large amounts is **harmful**, and the small amounts of aromatic hydrocarbons and sulfide impurities present in it are highly toxic. The main routes of exposure are inhalation or skin contact. **Standard (GB 1669-96) —————————————————————————— Item Quality Index Test Method —————————————————————————— Boiling range: GB/T 6536 Initial boiling point, °C Not less than 60 98% distillation temperature, °C Not more than 90 Aromatic content, % Not more than 1.0 SH/T 0166 Density (20°C), kg/m³ 655–686 GB/T 1884 and GB/T 1885 Bromine index Not more than 1000 GB/T 11134 Colority, units Not less than +25 GB/T 3555 Non-volatile matter, mg/100mL Not more than 3 GB/T 3209 Sulfur content, % (m/m) Not more than 0.012 SH/T 0253 Mechanical impurities and water Absent Copper sheet corrosion (50°C, 3h), grade Not more than 1 GB/T 5096 Water-soluble acids or bases Absent Oil stain test Pass ——————————————————————————— Note: (1) The oil sample should be poured into a 100 mL measuring cylinder; it should be transparent and free of any suspended or settled mechanical impurities or water. It is then called “none”, otherwise it is called “yes”. (2) Oil stain test method: Transfer the residue from the solvent oil distillation test to a clean test tube or measuring cylinder using small filter paper. Use a pipette to take the filtrate and drop 3 drops of it on clean filter paper. Leave it at room temperature (20°C ± 30°C) for 30 minutes; if no oil stains appear on the filter paper, it is considered satisfactory.