Effect of Phenol Content on The Purity of Methyl Salicylate USP

Methyl salicylate, also known as wintergreen oil, CAS 119-36-8, is a commonly used synthetic fragrance and pharmaceutical intermediate. When it is used in fragrances, cosmetics and pharmaceuticals, its phenol content is particularly stringent. Therefore, when producing METHYL SALICYLATE PHARMACEUTICAL GRADE, the content of phenol should be strictly controlled.

Methyl salicylate is produced by the esterification reaction of salicylic acid and methanol. Phenol is usually not a raw material or catalyst for the reaction, so the phenol content in the finished product of methyl salicylate is usually very low or even negligible.However, phenol may be present as one of the impurities in the synthesis process of methyl salicylate, resulting in its trace residues in the finished product of methyl salicylate. The presence of phenol may have an impact on the quality of methyl salicylate, and therefore the phenol content needs to be tested and controlled in some cases.

Phenol content needs to be determined by analytical testing methods. Commonly used methods include gas chromatography (GC) and high performance liquid chromatography (HPLC) techniques. If the phenol content exceeds the relevant regulatory limits, appropriate handling and adjustments are required to ensure the quality and safety of methyl salicylate.

Normally, with phenol content ⩽200ppm, the finished methyl salicylate can be used in fragrances, cosmetics and pharmaceuticals; while with phenol content >200ppm, we generally call it METHYL SALICYLATE TECHNICAL GRADE.