Dimethyl sulfoxide smell

The odor description of dimethyl sulfoxide (DMSO) varies from a strong odor, similar to that of rotten eggs or garlic, to a slight odor, or even colorless and odorless.
This difference may be due to differences in the concentration and purity of DSO from different sources.
1. Properties and uses of dimethyl sulfoxide
Dimethyl sulfoxide (DMSO) is a colorless, transparent, organic solvent with excellent solubility and solubility. It is mainly used in organic synthesis, catalytic reaction, REDOX reaction and preparation of polymer materials. In addition, DMSO has certain medicinal value and is used as a drug delivery and efficacy enhancer in pharmacy.

Dimethyl sulfoxide taste
Although DMSO has a wide range of applications, it is also an organic solvent with a strong odor. It smells similar to rotten eggs or garlic, and can even pass through work clothes and gloves to produce a pungent smell. Therefore, when using DMSO, we must pay attention to ventilation, and wear the mask and gloves in the work area correctly.
In short, dimethyl sulfoxide is a very useful organic solvent, but it also has an unpleasant odor. Be sure to pay attention to relevant safety matters when using to ensure safe operation.

Purification and dewatering methods
Dimethyl sulfoxide can be mixed with water and can be dried by molecular sieve for a long time. The 76 ° C /1600Pa(12mmHg) fraction is then distilled under vacuum. When distillation, the temperature should not be higher than 90 ° C, otherwise disproportionation will occur to form dimethyl sulfone and dimethyl sulfide. Calcium oxide, calcium hydride, barium oxide or anhydrous barium sulfate can also be dried and then distilled under vacuum. It can also be purified by partial crystallization. Dimethyl sulfoxide may explode when mixed with certain substances, such as sodium hydride, periodate or magnesium perchlorate.
Identification and detection methods
[Identification] Take 1.5ml of this product, slowly drop it into 2.5ml of cooled hydroiodic acid, rapidly filter it, and dry it under reduced pressure. The resulting residue is an unstable dark purple crystalline solid with unpleasant odor, dissolved in chloroform and formed a red solution.
[Check] Light absorption Take an appropriate amount of this product, pass it into dry nitrogen stream for 15 minutes, immediately place it in a 1cm absorption tank, use water as blank, and measure the absorption at 275nm wavelength by spectrophotometry (page 24 of the Appendix of the second part of the Chinese Pharmacopoeia 1990 edition), not more than 0.30Chemicalbook; Then the absorption was measured at the wavelength of 285nm and 295nm, and the ratio of the absorption at 275nm should not be greater than 0.65 and 0.45, respectively, and there should be no maximum absorption peak in the range of 270-350nm. Water content shall not exceed 0.2% (page 55 of the Appendix of the second part of the Chinese Pharmacopoeia, 1990 edition). 0.025% acetone solution was prepared by taking diphenylmethane from dimethyl sulfone as the internal standard solution. Accurately weigh the appropriate amount of dimethyl sulfone and dilute it into 0.050% solution with internal standard solution as a control solution; Another appropriate amount of this product, precision weighing, with the internal standard solution diluted into 50% solution, as the test product solution. According to gas chromatography (Chinese Pharmacopoeia 1990, Part II Appendix 31 page (3) method), with a coating concentration of 10% polyethylene glycol 20M as the fixed liquid, (the theoretical plate number calculated by dimethyl sulfone should be greater than 1500, the separation degree of dimethyl sulfone peak and internal standard peak should be greater than 2), The ratio of peak area between dimethyl sulfone and diphenylmethane in test solution measured at 150℃ should not be greater than that between dimethyl sulfone and diphenylmethane in control solution.
Reference quality standard
External use – DMSO quality technical index
Content, GC, %, ≥ 99.9 GB/2307-1986) Gas Chromatography
IR evaluation, qualified EP
Chemical identification, qualified EP
Crystallization point, ℃ ≥ 18.3 GB/T7533-1993
Refractive index 1.478-1.479GB /T6488-1986
Moisture,%,KF, ≤ 0.2GB /T6283-1986
Uv extinction value,275nm ≤ 0.3GB 9721-1988
285nm ≤ 0.2
295nm ≤ 0.2
Heavy metals, PPm ≤ 10 GB/7532-1987
Specific gravity (20℃), 1.100-1.104 GB/4472-1984
Acid value (0.1N/ml NaOH/50g), ≤ 5.0GB / 9376-1988
Packing: PE plastic drum
Waterless grade – DMSO quality technical index
Content (DMSO),GC %, ≥ 99.9 GB/2307– 1986)Gas Chromatography
Crystallization point, ℃, ≥ 18.35GB /T7533-1993
Acid value mgKOH/g, ≤ 0.001 GB/T9736-1988
Refractive index (20℃), 1.478-1.479GB /6488– 1986
Moisture, %, KF, ≤ 0.001 GB/6283–1986
Evaporation residue,PPM, ≤ 5.GB /T3209—-82
Heavy metals,%, ≤ 10.GB /T7532—-87
Packing: PE plastic drum
Toxicity
GRAS(FEMA). Studies have shown that dimethyl sulfoxide DMSO has serious toxic effects, interacts with protein hydrophobic groups, leads to protein denaturation, and has vascular toxicity and hepatorenal toxicity. DMSO is a relatively toxic thing, when using Chemicalbook to avoid its volatilization, to prepare 1%-5% ammonia water standby, after the skin with a lot of water and dilute ammonia wash. The most common side effects are nausea, vomiting, rash, and garlic, onion, and oyster smells on the skin and in exhaled air.
Use limited FEMA(mg/kg) baked products, non-alcoholic beverages, breakfast cereals, cold drinks, sauces, meat products, dairy products, soft candy, soup, sweet sauce, 0.1 ~ 5.0; Spices 100 ~ 1000.