Rapid high-performance liquid chromatographic method for the quantification of tomatine in tomato

A method for the determination of the glycoalkaloid a-tomatine in tomatoes and tomato plant material is described. The a-tomatine is extracted with methanol and subsequently prepared for analysis using a CIS cartridge column. The a-tomatine was applied on the cartridge in 40% methanol and eluted with 80% methanol. A Nucleosil5-NHz column was employed for the high-performance liquid chromatography (HPLC) with acetonitrile-20 mM potassium dihydrogen phosphate (75:25, v/v, pH 6.1) as the mobile phase. Recoveries of spiked a-tomatine ranged from 91% to 98% for different amounts spiked. The calibration graph was linear in the range 5-250 pg/mL for a-tomatine. Survey data are presented for tomatoes and tomato plant material collected from commercial growers and from the Dutch auctions.