Analysis of green tea catechins: comparative study between HPLC and HPCE

A comparison between a borate–phosphate–SDS based MEKC and an RP-HPLC method for the separation of seven tea catechins and gallic acid in a green tea extract is here proposed. Under optimised conditions, HPCE offered several advantages respect to time of analysis (compounds were separated within 4.5 min), sensitivity (HPCE LODs were about 20–100 times lower than HPLC ones) and solvent consumption. HPCE displayed excellent migration time repeatability (RSD% on MT <2%, and RSD% on RMT <1%), whereas HPLC showed slightly more quantification ruggedness (total amount catechins RSD% was <2% for HPLC and <6% for HPCE). This study highlights the effective possibilities of application of HPCE in the food chemistry field for routine analysis.