A novel flow-through fluorescence optosensor for the determination of thiabendazole.

This paper presents the development of a new flow-injection system combined with solid-surface fluorescence detection for the determination of the widely used fungicide thiabendazole. Nylon powder was probed as a novel solid support for building the optosensor. The method is based on the on-line immobilization of thiabendazole onto nylon in a continuous flow system, followed by the measurement of its native fluorescence. Aqueous samples are directly injected in a water carrier, resulting in a very simple and economical method. The analytical figures of merit obtained using 1500 microL of sample and 75% methanol (v/v) as eluting solution were: linear calibration range from 8 to 120 ng mL(-1) (the lowest value corresponds to the quantitation limit), relative standard deviation, 0.9% (n=5) at a level of 64 ng mL(-1), limit of detection calculated according to 1995 IUPAC recommendations is to 2.8 ng mL(-1), and sampling rate of 14 samples h(-1). The potential interference from other agrochemicals, metal ions and common anions, and the viability of determining thiabendazole in real water samples were also evaluated.