Porous covalent triazine-terphenyl polymer as hydrophilic-lipophilic balanced sorbent for solid phase extraction of tetracyclines in animal derived foods.

A novel hydrophilic-lipophilic balanced (HLB) solid phase extraction sorbent, microporous covalent triazine-terphenyl polymer (CTP) was successfully synthesized and applied for the cleanup and extraction of tetracycline drugs in animal derived food samples. The specific ratio of two monomers, hydrophilic triazine and lipophilic aromatic rings, endowed the new material with hydrophilic-lipophilic balanced character, which made it capable of extracting both polar and nonpolar analytes. Prior to solid-phase extraction, food samples were extracted by McIlvaine buffer and passed through the CTP cartridge. The experimental parameters affecting extraction efficiency, including loading, washing and elution were investigated and optimized. With the use of high-performance liquid chromatography-UV detection, a method detection limit in the range of 8.0-16.8 μg kg and good linearity (22.6-1500 μg kg) for the determination of the tetracyclines in animal derived food samples can be achieved. The relative standard deviations (RSDs) for five replicate extractions of the tetracyclines ranged from 4.8 to 8.2%. The method recoveries for spiked tetracyclines (100 and 1000 μg kg) in bovine milk, egg, chicken liver samples were in the range of 81.3-98.7% with RSDs ranging from 3.9 to 7.7%, respectively, depending on both the analytes and samples. The method was suitable for the determination of tetracyclines in animal derived food samples.