Determination of Pharmaceutical Preparations by Gas Chromatography. IV. Determination of Al-acetylsalicylic Acid Preparations

Abstract

Aluminium-acetylsalicylic acid (Asp-Al), phenacetin, caffeine, and acetaminophen were determined by gas-liquid chromatography with hydrogen flame ionization detector on a 2-m column of 10% QF-1, at 170°. i) For Asp-Al, phenacetin, and caffeine preparations, mixture of these three was added to 40 ml of 0.5% sodium fluoride solution (0.2N HCl) at room temperature. After 20 min, only Asp-Al was decomposed to acetylsalicylic acid, and acetylsalicylic acid, phenacetin, and caffeine were extracted with chloroform. The solvent was evaporated from the extract on a water bath and the cooled residue was silanized. ii) For Asp-Al, AA and caffeine preparations, AA and caffeine were extracted with chloroformacetone (1 : 1) mixture, and the residue which contains Asp-Al was added to 40 ml of 0.5% sodium fluoride solution (0.2N HCl) at room temperature. After 20 min, acetylsalicylic acid was extracted with chloro-form. This chloroform solution was mixed with the former chloroform-acetone solution, and this was evaporated on a water bath. The cooled residue was silanized. Determination was made successfully by the internal standard method using dipropyl phthalate.