IMPROVED HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC METHOD FOR THE ANALYSIS OF POTATO (SOLANUM-TUBEROSUM) GLYCOALKALOIDS

An improved high-performance liquid chromatographic (HPLC) method for the determination of the potato glycoalkaloids, alpha-solanine and alp ha-chaconine, is described. The glycoalkaloids were extracted with aqu eous acetic acid, concentrated, and cleaned up by solid phase extracti on using C-18 cartridge columns and separated using a reverse phase C- 18 HPLC column. Recoveries averaged 93% +/- 1.3 for alpha-solanine and 99% +/- 3.1 for alpha-chaconine. Comparisons were made at each step w ith existing published methods. We conclude that trifunctional endcapp ed C-18 SPE cartridges were more reliable than traditional monofunctio nal non-endcapped cartridges and that low carbon load C-18 HPLC column s provided an improved separation of glycoalkaloids when compared to c olumns with a high carbon loading. An acidic extraction medium excludi ng organic solvents is recommended.