Magnetic MWCNT@guanidine acetic acid@Cu as a nanosorbent for ultrasonic assisted dispersive magnetic solid phase extraction of heterocyclic pesticides in citrus samples

In the current research, copper supported on magnetic multi-wall carbon nanotubes functionalized with guanidine acetic acid (MMWCNT@GAA@Cu) as a novel nanosorbent for ultrasonic assisted dispersive magnetic solid phase extraction (UA-DMSPE) method was designed and synthesized. UA-DMSPE was combined with corona discharge ion mobility spectrometry for trace detection of tribenuron-methyl, fenpyroximate, and iprodione. Corona discharge ion mobility spectrometry is a well-known, comparatively inexpensive, robust and easy to operate analytical instrumentation. This combination would provide a selective and sensitive determination. MMWCNT@GAA@Cu showed acceptable extraction efficiencies for heterocyclic pesticides mainly via interaction with copper. In order to achieve the best extraction efficiency, effective parameters were studied and optimized. The proposed method, under optimal conditions, showed excellent linearity in different ranges (1-700, R-2 > 0.991), good repeatability (RSD < 6.7%), good sensitivity (LODs in the range of 0.3-1.5 ng mL(-1)), high preconcentration factor (398-427), extraction recoveries (80-85%) and acceptable relative recoveries (93.7-102.2%). Eventually, this method was used to determine heterocyclic pesticides in citrus fruit samples.