High resolution continuum source atomic absorption spectrometry and solid phase extraction for the simultaneous separation/preconcentration and sequential monitoring of Sb, Bi, Sn and Hg in low concentrations

Abstract

A rapid method was developed for separation, pre-concentration and sequential determination of antimony, bismuth, tin and mercury by flow injection solid phase extraction coupled with on-line chemical vapor generation electrothermal atomic absorption spectrometry. The system is based on chelating/cationic retention of the analytes onto a mini-column filled with a mesoporous silica functionalized with 1,5 bis(di-2-pyridyl)methylene thiocarbohydrazide. Several variables (sample flow rate, eluent flow rate, eluent concentration and reductant concentration) were considered as factors in the optimization process. Interactions between analytical factors and their optimal levels were investigated using three central composite designs. The optimized operating conditions were: sample pH ¼ 2.2, sample flow rate 3 mL min À1 , eluent flow rate 2.5 mL min À1 , eluent 3.1% HCl for Sb, Bi and Sn, and 4.6% thiourea for Hg, and 0.6% NaBH 4 reductant. The optimum conditions established were applied to the determination of Sb, Bi, Sn and Hg in sea water and river water by flow injection solid phase extraction coupled with on-line chemical vapor generation high resolution continuum source electrothermal atomic absorption spectrometry (FI-SPE-CVG-CS ETAAS). For the quality control of the analytical performance and the validation of the newly developed method, the analysis of two certified samples, TM 24.3 and TMDA 54.4, Fortified Lake Waters was addressed. The results showed good agreement with the certified values.

Recent advances in flow injection analysis

“…in an FIA system for sequential but practically almost simultaneous monitoring of Sb, Bi, Sn and Hg. 326 The developed system involved on-line SPE preconcentration on chelating sorbent, then reduction of preconcentrated analytes with NaBH 4 , followed by the introduction of a cold vapor into the graphite furnace by a stream of argon for 45 s. Using a different furnace program for each analyte and the advantage of a continuum source, the sequential determination of all analytes can be carried out with a time run for each analyte of about 2 min. The obtained LOD values were 1 and 9 ng L −1 for Bi and Sb, and 0.17 and 0.18 mg L −1 for Hg and Sn, respectively, which can be satisfactory for various applications.…”

Simultaneous Determination of As, Bi, Sb, Se, Te, Hg, Pb and Sn by Small-Sized Electrothermal Vaporization Capacitively Coupled Plasma Microtorch Optical Emission Spectrometry Using Direct Liquid Microsampling

“…Furthermore, the LODs of As and Se were poorer than in GFAAS [ 40 ], while the LOD of As was poorer than in HR-CS-GFAAS with direct solid sampling of soil [ 43 ]. Compared to CVG-HR-CS-GFAAS with in situ hydride trapping, LODs for As, Bi, and Sb were poorer, while that for Hg was quite similar [ 20 , 42 ]. In this comparative evaluation of the detection limits, the benefits of the miniature SSETV-µCCP-OES instrumentation were associated to low cost, and the low power/low Ar consumption of plasma microtorch should not be ignored.…”

“…The direct determination of chemical vapor-generating elements by avoiding derivatization was also attempted. Therefore, mercury determination by thermal decomposition atomic absorption spectrometry (TD-AAS) [ 37 , 38 ], liquid/solid sampling with electrothermal vaporization (ETV) in GFAAS [ 39 , 40 , 41 ], or the emergent HR-CS-ETAAS using Xe lamp [ 42 , 43 ] were successfully applied. At the same time, ICP OES [ 44 ] and ICP-MS [ 45 , 46 ] using pneumatic and ultrasonic nebulization, or solid sampling by laser ablation (LA-ICP-MS) [ 47 ] and LIBS OES [ 48 ] provide simultaneous direct determination without derivatization.…”

Paper-Based Analytical Devices for Colorimetric and Luminescent Detection of Mercury in Waters: An Overview

“…For the determination of Hg at the (ultra)trace level, conventional instrumentation is typically used in central labs on a routine basis, such as cold vapor-atomic absorption spectrometry (CV-AAS) [12], cold vapor-atomic fluorescence spectrometry (CV-AFS) [13], electrothermal atomic absorption spectrometry (ETAAS) [14], inductively coupled plasmamass spectrometry (ICP-MS) [15] and total reflection X-ray fluorescence (TXRF) [16]. While these techniques provide adequate sensitivity and precision, they require suitable sampling, preservation procedures, sample pretreatment and a fully controlled laboratory environment, which makes it difficult to extend their application for on-field analysis [17].…”