Tailoring of amino functionalized graphene oxide/cellulose/chitosan composite for the determination of imidacloprid...

Cellulose and chitosan, due to their high mechanical strength and active functional groups are preferred in designing novel composites for solid phase extraction of diverse analytes from food, biological or environmental samples. In this study, an amino functionalized graphene oxide, cellulose and chitosan-based composite was designed and well characterized for the analysis of imidacloprid (IMI) in cow milk samples. Characterization of synthesized composite was done by using Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray, thermogravimetric analysis and differential scanning calorimetry. Limit of detection and quantification of pesticide were found to be 5.5 × 10^-3 mgL^-1 and 1.65 × 10^-2 mgL^-1. Kinetic studies revealed that the adsorption process was governed by the pseudo first order mechanism. Optimization of different parameters revealed that best conditions for IMI adsorption were pH 5, adsorbent dose of 20 mg, IMI concentration of 35 mgL^-1 and the contact time of 20 min. Thermodynamic studies showed ΔH° value of +20.0 kJmol^-1, ΔS^°, +155.1 JK^-1 mol^-1 and ΔG^° at 298 K, 308 K, 318 K was -26.13, -27.68 and - 29.23 kJmol^-1, respectively. To evaluate the real-time application of designed composite, IMI was determined in cow milk samples using dispersive solid phase microextraction followed by high-performance liquid chromatography. The composite showed a high percentage recovery of 95.4 ± 4.1% (n = 9) of IMI. These results indicate the effectiveness of composite in detecting the IMI in complex matrixes like milk, thus highlighting its effectiveness and potential as a reliable method in food analysis.