The use of cloud point extraction and hydride generation for improving the Sb and Se limits of detection in ICP OES

Abstract

O presente estudo trata da aplicação da extração no ponto nuvem (CPE) e geração de hidretos (HG) para a determinação de Sb e Se por espectrometria de emissão óptica com plasma indutivamente acoplado (ICP OES). O complexante utilizado foi o dietilditiofosfato de amônio (DDTP), enquanto que Triton X-114 foi usado como surfactante para a formação das micelas. As condições para a pré-concentração de Sb(III) e Se(IV), redução de Se(VI) e Sb(V), geração dos respectivos hidretos e interferências foram avaliadas e discutidas. O desempenho da HG foi comparado com o da nebulização pneumática (PN) para introduzir a fase rica em surfactante no plasma. Mediante aplicação da HG, os limites de detecção obtidos para Se(IV) e Sb(III) foram 0,05 e 0,08 µg L This study deals with the application of cloud point extraction (CPE) and hydride generation (HG) for determination of Sb and Se using inductively coupled plasma optical emission spectrometry (ICP OES). The complexing agent was ammonium diethylditiophosphate (DDTP), whereas Triton X-114 was used as surfactant for the formation of micelles. Conditions for Sb(III) and Se(IV) preconcentration, reduction of Se(VI) and Sb(V), hydrides generation and interferences were discussed. The performance of HG was compared with pneumatic nebulization (PN) for introducing the surfactant-rich phase into the plasma. Upon application of HG, the limits of detection (LODs) for Se(IV) and Sb(III) were 0.05 and 0.08 mg L -1 , respectively. Limits of detection using PN were 0.90 and 2.90 ug L -1 for Se(IV) and Sb(III), respectively. Samples of nuts, water and white wine were analyzed. Selenium(IV) was quantified in Brazil nut whereas Sb(III) was in estuarine water, seawater and mineral water stored in polyethylene terephthalate (PET) bottle.

Speciation of Antimony(III) and Antimony(V) in Bottled Water by Hydride Generation-Inductively Coupled Plasma Optical Emission Spectrometry

“…Besides, a negligible signal was verified for Sb(V) at 0.50 L min 1 , and, hence, this value was adopted for subsequent experiments. This parameter was not comparable to results from the literature, which reported the use of flow rates of 0.75 L min 1 (Feng et al 1999) and 0.60 L min 1 (Menegario et al 2006;Menegario et al 2008;Depoi and Pozebon 2012). Hence, lower argon consumption was achived in the optimum conditions employed in this study.…”

“…Various analytical methods have been used for the determination and speciation of the inorganic antimony, such as high-performance liquid chromatography with inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) (Smichowski et al 1995;Zheng, Iijima, and Furuta 2001;Ge and Wei 2013;Jablońska-Czapla et al 2014), atomic absorption spectrometry (AAS) (Fan 2005;Zheng et al 2006;Flores et al 2007;Matusiewicz and Krawczyk 2008;Ferreira et al 2011), atomic fluorescence spectrometry (Deng, Chen, and Belzile 2001), inductively coupled plasma optical emission spectrometry (ICP OES) (Menegario et al 2006;Menegario et al 2008;Depoi and Pozebon 2012), and inductively coupled plasma-mass spectrometry (ICP-MS) (Westerhoff et al 2008). Spectrometric techniques have been used for the speciation of Sb (Feng et al 1999;Menegario et al 2006;Zheng et al 2006;Flores et al 2007;Menegario et al 2008 Ferreira et al 2011) using hydride generation (HG) systems with adequate sensitivity.…”

“…However, for hydride generation methods such as HG-ICP OES (Menegario et al 2006;Depoi and Pozebon 2012), usually a preconcentration procedure is necessary to achieve low limits of detection. The main goal of this study was the improvement of the conditions for determination and speciation of Sb(III) and Sb(V).…”

Separation/preconcentration of ultra-trace levels of inorganic Sb and Se from different sample matrices by charge transfer sensitized ion-pairing using ultrasonic-assisted cloud point extraction prior to their speciation and determination by hydride generation AAS

“…While only one factor is changed, others are kept at a constant level. Although, the optimization performed by univariate does not ensure at all that 13 the real optimum will be conformed, but it would be valid only if the variables to be optimized would be totally independent from each other (i.e. no interactive effects among the variables) [41].…”

“…The most important advantages of ultrasonic assisted cloud point extraction (UA-CPE) include simple, cheap, rapid, and high preconcentration rate capability, and have also low environmental toxicity because it does not use toxic volatile organic solvents [9]. The UA-CPE has efficiently been used in combination with various chromatographic and atomic techniques in order to determine simultaneously a number of analytes present in the samples using various detection techniques [10] whereas the CPE is used in separation and preconcentration of inorganic Sb and Se from different matrices using chelating agents pyronin B, azomethine-H, victoria pure blue BO and diethyldithiophosphate prior to speciation analysis by spectrophotometry, flame AAS and ICP-OES with hydride generation [11][12][13][14][15]. 4 After various preconcentration procedures such as coprecipitation [16], selective adsorption onto nanometer-sized TiO 2 [17], liquid-liquid microextraction (LLME) [2,18], headspace solid phase microextraction (HS-SPME) [10], ultrasound assisted-hollow fiber liquid-phase microextraction (UA-HF-LPME) [19], on-line ionic liquid dispersive microextraction (on line ILDME) [20], and cloud point extraction (CPE) [21,22], ultrasound-assisted emulsification microextraction (UA-EME) [23], on-line solid-phase extraction (SPE) using single-walled carbon nanotubes micro-column [24], several analytical techniques like graphite furnace atomic absorption spectrometry (GF-AAS) [2], inductively coupled plasma optical emission spectroscopy (ICP-OES) [10], gas chromatography-mass spectrometry (GC-MS) [18], electrothermal atomic absorption spectrometry (ETAAS) [22], hydride generation-double channel atomic fluorescence spectrometry (HG-DC-AFS) [24], hydride generation atomic fluorescence spectrometry (HG-AFS) [25][26][27], electrothermal vaporization inductively coupled plasma mass spectrometry (ETV-ICP-MS) [28], gas chromatography-electroncapture detection (GC-ECD) …”