Abstract
In April 2008, the polysorbates emulsifiers (PSs) were approved as food additives, thereafter it has been increasingly used in Japan. The analytical method in foods was notified by the Ministry Health, Labour and Welfare. In the official method, PSs were extracted from processed foods with the mixture of acetonitrile-methanol-n-hexane and the extract was cleaned up on an alumina column and a silica gel cartridge to remove food color and other interfering substances. In such a complicated process, including salting-out and liquid-liquid partition, this method often showed poor recovery of PSs. To simplify operations and improve purification process and recovery rates, we have examined commercially available column cartridges: a silica gel, a diol, an Ag-ion, an alumina-B, and a graphitized carbon black column cartridges. In this paper, we propose an effective new method for analysis of PSs. A new method uses ethyl acetate containing 10% methanol for extraction of PSs, and a diol cartridge (MEGA Bond Elut-Diol) and an Alumina-B cartridge (Sep-Pak Plus Alumina B) for removal of fat and food color. The presence and the content of PSs are determined by TLC and colorimetric assay, respectively. Using a new method, the recoveries of PS80 in foods fortified at the levels 0.05-5 g/kg ranged from 47 to 89%. The limit of quantitation for PS80 in foods was 0.05 g/kg.
