| Polymeric membrane ion-selective electrodes (ISEs) received much attention among the electrochemical sensors and have been routinely used for environmental monitoring, industrial analysis, clinical and other areas owing to their highly sensitive and selective detection capabilities, and other excellent feature, such as easy-to-use and low cost. Despite the outstanding potential of polymeric membrane ion-selective electrodes, the ISEs device generally unable to detect trace-level organic pollutants in real samples such as in seawater because of the high levels of salt background and the large amounts of natural organic matters, which produce erroneous response characteristics even damage to the structure of membrane via adsorption and extraction processes. In addition, the concentration of target organic pollutants in seawater are too low to be determined directly by ISEs, therefore the samples should be pre-concentrated before analysis.Molecularly imprinted polymers (MIPs) have emerged as attractive general materials in the analysis field, since they are specific selective recognition for target molecular, resist harsh environments and highly stable. By using on-line molecularly imprinted solid-phase extraction (MISPE) at the upstream of ISEs, interferences from water matrixes can be effectively eliminated and the concentrated trace-level target is obtained.In order to verify the feasibility of the method aforementioned, chlorpyrifos, the common organophosphate pesticide was choose as target, and seawater, with the most complex matrix was selected as the detection background in this study. Thus, this paper describes an on-line hyphenated system consists of enrichment of trace-level chlorpyrifos in seawater with molecularly imprinted solid-phase extraction (MISPE) and potentiometric measurement with polymeric membrane ion-selective electrode. A new potentiometric detection system for detection of trace-level chlorpyrifos (CPF) in real seawater samples is obtained. This device can perform automated electrochemical analysis in complex matrices and reliable, provide rapid and inexpensive measurements of CPF, offer a low detection limit of0.027nmol L"1and the RSD of6.5%(n=3). |
