Determination of selected phytochemicals by reversed-phase high-performance liquid chromatography combined with...

A robust, routinely manageable and sensitive RP-HPLC method combined with UV (270 nm) and ESI-MS detection was established for the determination of abundant pertinent phenolic compounds (phytochemicals) from various biological matrices. Phytochemicals were extracted by aqueous methanol (80%), extracts were analysed without further purification. Baseline separation was achieved within 30 min for 19 phytochemicals and excellent sensitivity (6-42 pmol at S/N = 3) was obtained. The identity of the phytochemicals was confirmed with standard compounds and with LC-MS. The repeatabilities for the majority of the phytochemicals ranged between 3% and 6%. The practicability of the method was shown in complex biological matrices by analysing onion and soybean extracts. This generally applicable technique may serve as a valuable tool for a rapid screening and a specific measurement of phytochemicals in food extracts and biological fluids and serve as analytical instrument for future biochemical and physiological studies.