Sodium chloride solutions and blood samples were shaken with equal volumes of chloroform which extracted approximately 70% of the Semi-H and avoided introducing interfering chloride ions into the chromogenic reaction mixture. The analytical procedure was then the same as for water except that the reaction mixture was altered to contain 10% chloroform and 45% instead of 55y0 isopropyl alcohol.
![S-[2-(diethylamino)ethyl] 2,2-diphenylethanethioate Structure](https://image.chemsrc.com/caspic/391/82-99-5.png)