Development of a molecularly imprinted solid-phase extraction sorbent for the selective extraction of telmisartan...

A novel molecularly imprinted solid-phase extraction with spectrofluorimetry method has been developed for the selective extraction of telmisartan from human urine. Molecularly imprinted polymers were prepared by a noncovalent imprinting approach through UV-radical polymerization using telmisartan as a template molecule, 2-dimethylamino ethyl methacrylate as a functional monomer, ethylene glycol dimethacrylate as a cross-linker, N,N-azobisisobutyronitrile as an initiator, chloroform as a porogen. Molecularly imprinted polymers and nonimprinted control polymer sorbents were dry-packed into solid-phase extraction cartridges, and eluates from cartridges were analyzed using a spectrofluorimeter. Limit of detection and limit of quantitation values were 11.0 and 36.0 ng/mL, respectively. A very high imprinting factor (16.1) was achieved and recovery values for the telmisartan spiked in human urine were in the range of 76.1-79.1%. In addition, relatively low within-day (0.14-1.6%) and between-day (0.11-1.31%) precision values were obtained. Valsartan was used to evaluate the selectivity of sorbent as well. As a result, a sensitive, selective, and simple molecularly imprinted solid-phase extraction with spectrofluorimetry method has been developed and successfully applied to the direct determination telmisartan in human urine.