Arsenic Speciation Analysis in Environmental Water by HG-AFS after Solid-Phase Extraction Using Multiwalled Carbon Nanotubes

2010 ◽  
Vol 113-116 ◽  
pp. 76-80 ◽  
Author(s):  
Xian Zhong Cheng ◽  
Xue Fang Sun ◽  
Cun Jie Hu ◽  
Chao Chang

A simple, inexpensive, and sensitive method was developed for the determination of inorganic arsenic species As(III), As(V) and total arsenic in environmental water samples using multiwalled carbon nanotubes (MWCNTs) as solid phase extraction (SPE) adsorbents coupled with hydride generation atomic fluorescence spectrometry (HG-AFS). The procedure is based on selectively absorbance of the chelates of As(III)-ammonium pyrrolidine dithiocarbamate (APDC) on the MWCNTs at pH range of 2.0-5.0, while As(V) was passed through the microcolumn. The retention complexes of As(III)-APDC was eluted completely with 3 mL of 2.0 mol L-1 HCl solution at a flow rate 1.0 mL min-1, and then directly determined by HG-AFS. The effluent of As(V) was determined using thiourea and ascorbic acid as reducing agent for reduce As(V) to As(III). The different parameters that control the preconcention/separation step of As(III) and As(V) and determination have been investigated in detail. Under the optimized conditions, a linear range of 0.03-10.0 ng mL-1 for As(III), along with a detection limits of 0.0026 ng mL-1, and the relative standard deviations for As(III) and As(V) for 0.28-6.30%, were obtained. The proposed method was applied for the analysis of inorganic arsenic species in groundwater and lake water with the recovery of 98.00-102.0%.

2020 ◽  
Vol 16 (4) ◽  
pp. 381-392
Author(s):  
Ayman A. Gouda ◽  
Ali H. Amin ◽  
Ibrahim S. Ali ◽  
Zakia Al Malah

Background: Cadmium (Cd2+) and lead (Pb2+) have acute and chronic effects on humans and other living organisms. In the present work, new, green and accurate dispersive micro solid-phase extraction (DμSPE) method for the separation and preconcentration of trace amounts of cadmium (Cd2+) and lead (Pb2+) ions in various food, water and tobacco samples collected from Saudi Arabia prior to its Flame Atomic Absorption Spectrometric (FAAS) determinations was developed. Methods: The proposed method was based on a combination of oxidized multiwalled carbon nanotubes (O-MWCNTs) with a new chelating agent 5-benzyl-4-[4-methoxybenzylideneamino)-4H- 1,2,4-triazole-3-thiol (BMBATT) to enrich and separate trace levels of Cd2+ and Pb2+. The effect of separation parameters was investigated. The validation of the proposed preconcentration procedure was performed using certified reference materials. Results: Analyte recovery values ranged from 95-102%, indicating that the method is highly accurate. Furthermore, precision was demonstrated by the relative standard deviation (RSD < 3.0%). The limits of detection were 0.08 and 0.1 μg L−1 for Cd2+ and Pb2+ ions, respectively. The preconcentration factor was 200. Conclusion: The proposed method was used for the estimation of Cd2+ and Pb2+ ion content in various real samples, and satisfactory results were obtained. The proposed method has high adsorption capacity, rapid adsorption equilibrium, extremely low LODs, high preconcentration factors and shortens the time of sample preparation in comparison to classical SPE.


2010 ◽  
Vol 96 (2) ◽  
pp. 348-351 ◽  
Author(s):  
Hideyuki Katsumata ◽  
Hiroshi Kojima ◽  
Satoshi Kaneco ◽  
Tohru Suzuki ◽  
Kiyohisa Ohta

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