Fast analysis of prominent flavonoids in tomato using a monolithic column and isocratic HPLC.

RP HPLC-UV-MS was optimized for simultaneous determination of several prominent flavonoids (quercetin, naringenin, naringin, myricetin, rutin and kaempferol) using a commercially available monolithic column and isocratic elution. The concentration of organic modifier (methanol and ACN) was tested in order to obtain the best resolution. The LODs for a UV detector at 254 nm were comprised between 0.1 microg/mL for myricetin and quercetin and 0.5 microg/mL for rutin, naringin and kaempferol with the precision in the range of 1.5-3.0% RSD. MS detection with multiply reaction monitoring (MRM) offers a considerable gain in selectivity as well as sensitivity LODs for flavonoids were in the range of 1-20 ng/mL. The developed method was used for monitoring the content of some flavonoids in tomatoes during their maturation process.