The amino - functionalized magnetic graphene oxide combined with graphite furnace atomic absorption spectrometry for determination of trace inorganic arsenic species in water samples

A novel adsorbent of magnetic graphene oxide (GO) chemically modified by cysteamine hydrochloride (Fe3O4@SiO2/GO-NH2) through thiol-ene click chemistry reaction was synthesized. The prepared Fe3O4@SiO2/GO-NH2 exhibit selective adsorption to As(V) with high adsorption capacity (52.66 mg g(-1)). Taking Fe3O4@SiO2/GO-NH2 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% (intraday, 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.

Automated summary

By synthesizing a novel adsorbent Fe3O4@SiO2/GO-NH2, a new method combining magnetic solid phase extraction (MSPE) and graphite furnace atomic absorption spectrometry (GFAAS) was developed for fast and efficient detection of trace arsenic species in water samples. After experimental optimization, the method achieved a detection limit of 1.02 ng L-1 for As(V) and provided accurate analysis results in real water samples.