Magnetic Poly(Amidoamine) Dendrimer for the Dispersive Solid Phase Extraction of Nitrophenols from Environmental Water Samples

A fast and simple dispersive solid phase extraction method is described for nitrophenols determination in water samples by using gas chromatography-nitrogen phosphorous detector. Firstly, the Poly(amidoamine) grafted Fe₃O₄ magnetic nanoparticles were synthesized in different generations by successive addition of butyl acrylate and ethylenediamine. After characterization, the prepared dendrimer was utilized as an adsorbent for magnetic solid phase extraction of 2-nitrophenol, 3-nitrophenol, and 4-nitrophenol to benefit large number of surface amine interaction sites. The effects of the different parameters influencing the sample preparation efficiency were investigated. The proposed method showed linearity in the ranges of 0.04–700 and 0.05–700 µg/dm³ for nitrophenols. The obtained limits of detection and quantification under optimized conditions were 0.01–0.02 and 0.04–0.05 µg/dm³, respectively. The relative standard deviations (n = 5) were less than 3.8% (at 10 µg/dm³). Moreover, the calculated enrichment factors were above 200. In addition, the relative recoveries for a spiked river water sample were satisfactory.