A novel method for picoxystrobin determination by flow injection chemiluminescence assistance with ultrasonic treatment

Abstract

A simple and sensitive flow injection chemiluminescence (FI-CL) method for determination of the fungicide picoxystrobin was described for the first time. Picoxystrobin was injected into the mixed stream of luminol with KMnO₄, and the CL signal of picoxystrobin could be greatly improved when an ultrasonic treatment was adopted. Meanwhile, the signal intensity increases with the analyte concentration proportionally. The effects of the ultrasonic conditions including ultrasonic frequency, time, power and temperature on the CL signal have been studied in detail. It was found that the higher the ultrasonic frequency used, the stronger the CL intensity increased. Since the variety of ultrasonic parameters can lead to the fluctuation of signal intensity, the CL mechanism was discussed. Under the optimized conditions, the CL intensity was linear for picoxystrobin concentration over the range of 2–150 ng mL⁻¹ with a 3σ detection limit of 0.27 ng mL⁻¹. The relative standard deviation was 3.9% for 11 consecutive measurements of 20 ng mL⁻¹ picoxystrobin. The method was demonstrated by application to spiked water samples from different origins including river, ground and tap water.