MULTI-SPE OF CAFFEINE AND CATECHIN COMPOUNDS FROM GREEN TEA BY CAFFEINE AND (+) CATECHIN MIPS

In this work, the caffeine and some catechin compounds (+) C, EC, and EGCG were extracted from green tea by using two molecular imprinted polymers (MIPs) as sorbent materials in a multi-solid-phase extraction (SPE) process known as MISPE (molecular imprinted solid-phase extraction). To obtain synthesis of MIP, (+) catechin (and caffeine) was employed as the template, AM (and MAA) as the monomer, EGDMA as the crosslinker, and AIBN as the initiator. A solution of (+) catechin (and caffeine) (0.2 mg/mL in methanol) was utilized in the solid extraction cartridges following loading, washing, and elution procedures with acetonitrile, methanol, and methanol/acetic acid (90/10, % v/v) as the solvents, respectively. This multi-solid-phase extraction protocol was applied for the extraction of caffeine and some catechin compounds from green tea. A comparison was made between the results obtained with the caffeine and (+) catechin MIP cartridges, blank polymer, and a traditional C(18) reversed-phase cartridge. It was thereupon found that the recovery of caffeine by the caffeine-MIP-based sorbent used in this work was almost two and four times greater than that by a commercially available C(18) material.