Development and application of a sol–gel immunosorbent-based method for the determination of isoproturon in surface water

An immunosorbent was fabricated by encapsulation of monoclonal anti-isoproturon antibodies in sol–gel matrix. The immunosorbent-based loading, rinsing and eluting processes were optimized. Based on these optimizations, the sol–gel immunosorbent (SG-IS) selectively extracted isoproturon from an artificial mixture of 68 pesticides. In addition to this high selectivity, the SG-IS proved to be reusable. The SG-IS was combined with liquid chromatography–tandem mass spectrometry (LC–MS–MS) to determine isoproturon in surface water, and the linear range was up to 2.2 μg/l with correlation coefficient higher than 0.99 and relative standard deviation (RSD) lower than 5% (n = 8). The limit of quantitation (LOQ) for 25-ml surface water sample was 5 ng/l.