Bifunctional magnesium oxide crystal successively as adsorbent and matrix modifier for preconcentration and determination of arsenic by graphite furnace atomic absorption spectrometry

Abstract

A novel method for determination of total inorganic arsenic in water samples, based on magnesium oxide crystals quantitatively preconcentration and graphite furnace atomic absorption spectrometry (GFAAS) detection has been developed. As the MgO crystals could successively act as the adsorbent and matrix modifier, the method presents great potential in practical routine analysis of inorganic arsenic. With optimization of the experimental conditions, 1.5 mg of MgO was added into 4.0 mL water sample and ultrasonic dispersing 15 min for adsorbing the arsenic at first. Then, the mixture was centrifuged 5 min for separating the adsorbents and the water solution; the deposits were collected and dissolved with HNO 3 for arsenic determination. The enrichment factor of 13, limit of detection (LOD) of 0.087 μg L −1 , relative standard deviation (RSD) of 4.5% (n = 7, c = 2.0 μg L −1) were achieved under the optimized conditions. The procedure was validated by analysis of certified water sample (GBW08605), which results in good agreement between the certified and the found values. The method was further demonstrated for analysis of lake water, snow water and tap water, and satisfactory spiked recoveries of 98.5% to 103.0% were achieved for these samples. These preliminary results indicated the present method was practical and accurate for analysis of trace-arsenic in natural water samples.

Dispersive solid phase microextraction based on magnesium oxide nanoparticles for preconcentration of auramine O and methylene blue from water samples

“…In their study, 1.5 mg MgO, pH 5.0, and 15 min ultrasonic time were selected as optimum reaction conditions. Under the optimal conditions, RSD (n = 7), LOD, and enrichment factor (EF) were about 4.5%, 0.087 μg L −1 , and 13, respectively 25 .…”

Trace Arsenic Determination in a TiO2 Pigment Matrix Using Electrothermal Atomic Absorption Spectrometry

“…13 For As determination, most of the literature describes food, wine, water, sediment, nanoparticles, human hair, soil, essential oil, marine tissue, and rose samples. 9,13,20,[26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42] This work describes the development of the ETAAS method by means of temperature program optimization after full TiO 2 sample decomposition using closed-vessel microwave-assisted digestion for the determination of trace amounts of As in a TiO 2 pigment matrix. The need for an appropriate chemical modifier mixture is also discussed.…”

Quantitative analysis of Pb in kelp samples and offshore seawater by laser-induced breakdown spectroscopy

“…Therefore, it is essential to detect the presence of Pb in the kelp. But the present methods of elemental analysis, such as inductively coupled plasma-atomic emission spectrometry [2][3][4], atomic absorption spectrometry [5,6], atomic fluorescence spectrometry [7,8], and x-ray fluorescence [9][10][11] are very expensive and require a long time for sample preparation due to the complex digestion procedure. It is not feasible to use these methods for the rapid detection of the concentration of Pb in kelp.…”