Abstract This paper presents the synthesis of a novel core–shell covalently functionalized Fe 3 O 4 coated SiO 2 decorated graphene oxides (Fe 3 O 4 @SiO 2 –GO) adsorbent. The prepared Fe 3 O 4 @SiO 2 –GO was characterized by fourier transform infrared spectrum, X-ray diffraction(XRD), X-ray photoelectron spectroscopy (XPS), and magnetic measurements. And the adsorption properties of the Fe 3 O 4 @SiO 2 –GO toward malachite green were systematically investigated. Various factors possibly affecting the adsorption behavior (initial concentration, contact time, and adsorbent dosage) were also studied in detail. The adsorption capacity (q m ) of Fe 3 O 4 @SiO 2 –GO for malachite green was found to be 265.87 mg/g with best fit to Langmuir isotherm ( R
2 = 0.968), and the adsorption mechanism follows the pseudo-second-order model ( R
2 = 0.981). The results indicate that the Fe 3 O 4 @SiO 2 –GO adsorbent, which is easily separated via an external magnetic field, is a potential low-cost effective material for malachite green removal from contaminated water. Graphical Abstract
Li Liang,Xinghua Wang,Ying Sun,Pinyi Ma,Xinpei Li,Huilan Piao,Yanxiao Jiang,Daqian Song
The metal-organic framework (MOF) functionalized magnetic graphene oxide/mesoporous silica composites (Fe 3 O 4 @SiO 2 -GO/MIL-101(Cr)) were synthesized and utilized as magnetic solid-phase extraction (MSPE) adsorbent for the extraction of seven triazine herbicides (terbuthylazine, secbumeton , terbumeton , atraton , atrazine , prometon and trietazine) in rice samples. Several experimental parameters, including type and volume of extraction solvent, amount of MIL-101(Cr), extraction time, volume of desorption solvent and desorption time were investigated and optimized. The limits of detection (LODs) of seven triazine herbicides obtained by using the proposed MSPE method combined with high performance liquid chromatography (HPLC) were in the range of 0.010–0.080 µg kg −1 . The recoveries of the triazine herbicides in spiked rice samples ranged from of 83.9–103.5% with the relative standard deviations lower than 8.7%. The intra and inter-day (n = 6) precisions for all triazine herbicides at the spiked level of 100.0 µg kg −1 were 1.4–5.9% and 2.6–7.8%, respectively.
A novel adsorbent of magnetic graphene oxide (GO) chemically modified by cysteamine hydrochloride (Fe 3 O 4 @SiO 2 /GO-NH 2 ) through thiol-ene click chemistry reaction was synthesized. The prepared Fe 3 O 4 @SiO 2 /GO-NH 2 exhibit selective adsorption to As(V) with high adsorption capacity (52.66 mg g −1 ). Taking Fe 3 O 4 @SiO 2 /GO-NH 2 as the adsorbents, a new method of magnetic solid phase extraction (MSPE) combined with graphite furnace atomic absorption spectrometry (GFAAS) was developed in determining trace-level inorganic arsenic species (As(III) and As(V)) in environmental water and bottled water samples. Various experimental parameters affecting the MSPE have been optimized. Under the optimal experimental parameters, the limit of detection of the established method for As(V) was 1.02 ng L −1 , the relative standard deviations were 7.9% (intra-day, c = 50 ng L −1 , n = 5) and 4.6% (inter-day, c = 50 ng L −1 , n = 7), respectively, and the enrichment factor of the method was 392. GBW08666 and GBW08667 (certified reference material) were analyzed to confirm the accuracy of the method, and the results were matched well with the certified values. The established MSPE-GFAAS method was successfully applied in analyzing trace/ultratrace As(III) and As(V) in real water samples.
危险品化学品经营许可证（带存储）