| 摘要 |
PURPOSE:To enable a highly accurate assay of Zn-DPT in a lubricant even after used by measuring zinc dithiophosphate Zn-DTP separated therefrom. CONSTITUTION:For example, a natural rubber membrance which allows the passage of a solvent A such as n-hexane dissolving a basic oil and Zn-DTP but not high polymer is used to separate the basic oil and Zn-DTP in a lubricant from high polymer components or the like in aditives. Then, the extraction liquid obtained is brought into contact with a adsorbent such as silica gel particle able to adsorb Zn-DTP but not the basic oil to adsorb Zn-DTP by the adsorbent. Additionally, a solvent B such as methylene chloride dissolving Zn- DTP is used to desorb Zn-DTP from the adsorbent. Zn-DTP in the desorption liquid thus obtained is assayed with an infrared absorptiometer or the like. This enables a highly accurate assay of Zn-DTP in the lubricant regardless of before or after the use thereof. |
