Magnetic Solid Phase Extraction Based on Nanostructured Magnetic Porous Porphyrin Organic Polymer for Simultaneous Extraction and Preconcentration of Neonicotinoid Insecticides From Surface Water
Shirley Kholofelo Selahle, Ngwako Joseas Waleng, Anele Mpupa, Philiswa N. Nomngongo
Abstract
In this study, a magnetic porphyrin-based porous organic polymer (MP-POP) nanocomposite was successfully synthesized according previous studies and applied as an adsorbent for simultaneous extraction and preconcentration of four neonicotinoid insecticides from surface river water. The MP-POP was characterised using X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy/energy dispersive x-ray spectroscopy (SEM/EDS), N2-adsorption/desorption analysis, Fourier Transform infrared spectroscopy (FTIR). The neonicotinoid insecticides were quantified using high performance chromatography coupled with diode array detector (HPLC-DAD). The MP-POP shown to have a high surface area, highly porous structure and strong affinity towards the investigated analytes. The adsorption capacities were 99.0, 85.5, 90.0 and 79.4 mg g−1 for acetamiprid, clothiandin, thiacloprid and imidacloprid, respectively. The influential parameters affecting the magmatic µ-solid phase extraction (M-µ-SPE) procedure were investigated using fractional factorial design and surface response methodology (RSM). Under optimum conditions, the method exhibited relatively low limit of detection in the range of 1.3-3.2 ng L−1, limit of quantification in the range of 4.3-11 ng L−1 and wide linearity (up to 600 µg L−1). The intraday and interday precision, expressed as the relative standard deviation (RSD) were less than 5%. The percentage recoveries for the four target analytes ranged from 91-99.3% for the spiked river water samples. The method was applied for determination of neonicotinoids in river water samples and concentrations ranged from 0-190 ng L−1.