On-line solid-phase extraction of triazine herbicides using a molecularly imprinted polymer for selective sample enrichment

A coupled-column system, consisting of a combination of a molecularly impri nted polymer (MIP) and a Cls-silica column, was used for selective triazine detection in the HPLC mode. Complex aqueous samples, spiked with triazines , were selectively extracted by the MIP followed by subsequent identificati on by analytical reversed-phase chromatography. The MIP showed good perform ance for selectivity discriminating triazines from humic acid, whereas urin e and apple extract had some tendency to be retained by the MIP. Enrichment was observed in all cases, and triazine-enrichment factors of up to 100 co uld be recorded, with good extraction efficiency (74-77%). The results indi cate that the high selectivity of MIPs can be favorably used for selective sample enrichment in conjunction with reversed-phase HPLC.