Determination of sodium dioctylsulfosuccinate in dry beverage bases by liquid chromatography with post-column...

Sodium dioctylsulfosuccinate (DSS) is extracted as an ion pair with methylene blue from finished drinks prepared from dry beverage bases. The complex is quantitatively determined colorimetrically in chloroform-acetone solution by a standard procedure. DSS is specifically identified by analyzing an aliquot of the extract by reverse phase liquid chromatography (LC). The compound is detected by using a simple post-column dynamic extraction system in which DSS is extracted from the aqueous mobile phase into chloroform as a methylene blue ion pair. The chloroform phase passes through the absorbance detector for measurement at 546 nm (filter detector). The absolute detection limit was 5-10 ng DSS, while in beverage bases as low as 0.1 microgram/g was detected. Extraction of the beverage bases with mobile phase followed by filtration and direct LC analysis with the described system was also successful, although not evaluated on a routine basis.