Rapid and accurate validated potentiometric method for bispyribac herbicide assessment in rice and agricultural wastewater

Abstract

A new validated method based on potentiometric transduction for bispyribac herbicide assessment in commercial formulations, rice and wastewater samples is fabricated and characterized. Sensors are based in terms of their fabrication on tridodecyl methyl ammonium chloride (TDMAC) as recognition material. TDMAC was plasticized in a poly (vinyl chloride) (PVC) matrix to prepare the membrane. Under static modes of operation, the sensors revealed a Nernstian anionic slope of-63.6 ± 0.7 mV/decade within a linear range of 9.1 x 10-6-1.0 x 10-2 in 50 mM phosphate buffer solution (PBS), pH7. The detection limit was 6.0 x 10-6 M. The sensor was successfully introduced in a flow-stream system revealing a Nernstian response of-53.8 ± 1.3 mV/decade over a linear range of 2 x 10-4-1.0 x 10-2 M and lower detection limit of 5.6 x 10-5 M. The sampling rate was calculated to be (~42 sample/h). Validation of the assay method is presented in detail including accuracy, trueness, bias, between-day variability and within-day variability, and good performance characteristics of the method are obtained. The presented method was successfully introduced to bispyribac determination in different complex matrices such as commercial bispyribac sodium known as (Nominee-kz, 3% soluble liquid (SL), rice samples and agricultural wastewater samples. The samples were analyzed successfully under both static and hydrodynamic modes of operation. The results obtained were in a good agreement with those obtained by the liquid chromatographic method.