Quantification of glycoalkaloids in tomato plants by time-resolved fluorescence using a europium chelator entrapped in liposomes.

In the control of tomato transgenic cultivars it is important to determine the glycoalkaloid content, which requires the screening of many samples. We have developed a simple method for the extraction and determination of glycoalkaloids in the leaf and fruit extracts of tomatoes using a europium chelator entrapped in phosphatidylcholine-cholesterol containing liposomes. The concentration values were quantified from liposome lysis effected by glycoalkaloid action. The fluorescent signal is linear between 1 and 10 micrograms of tomatine, which makes the method useful for the analysis of tomato samples.