Development of a Titanium Dioxide-Coated Microfluidic-Based Photocatalyst-Assisted Reduction Device to Couple High-Performance Liquid Chromatography with Inductively Coupled Plasma-Mass Spectrometry for Determination of Inorganic Selenium Species

Abstract

We developed a selective and sensitive hyphenated system employing a microfluidic-based vapor generation (VG) system in conjunction with high-performance liquid chromatography (HPLC) separation and inductively coupled plasma-mass spectrometry (ICPMS) detection for the determination of trace inorganic selenium (Se) species. The VG system exploited poly(methyl methacrylate) (PMMA) substrates of high optical quality to fabricate a microfluidic-based photocatalyst-assisted reduction device (microfluidic-based PCARD). Moreover, to reduce the consumption of photocatalysts during analytical procedures, a microfluidic-based PCARD coated with titanium dioxide nanoparticles (nano-TiO2) was employed to avoid consecutive loading. Notably, to simplify the coating procedure and improve the stability of the coating materials, a dynamic coating method was utilized. Under the optimized conditions for the selenicals of interest, the online HPLC/TiO2-coated microfluidic-based PCARD/ICPMS system enabled us to achieve detection limits (based on 3σ) of 0.043 and 0.042 μg L(-1) for Se(IV) and Se(VI), respectively. Both Se(IV) and Se(VI) could be efficiently vaporized within 15 s, while a series of validation experiments indicated that our proposed method could be satisfactorily applied to the determination of inorganic Se species in the environmental water samples.

Simultaneous speciation of inorganic arsenic, selenium and tellurium in environmental water samples by dispersive liquid liquid microextraction combined with electrothermal vaporization inductively coupled plasma mass spectrometry

“…Up to now, a variety of analytical methods have been employed for detection of As, Se and Te in water, such as AAS [21,28], atomic fluorescence spectrometry (AFS) [30,31], inductively coupled plasma optical emission spectrometry (ICP-OES) [32] and ICP-MS [33][34][35]. Among these techniques, ICP-MS is widely employed due to its merits of high sensitivity, wide linear range, multi-element and multi-isotope detection.…”

Two water‐soluble fluorescence probes based on 5(6)‐carboxyl rhodamine for Cu2+ imaging in living cells

“…[ 3 ] However, under overloading conditions, copper exhibits toxicity, in that it causes neurodegenerative diseases such as Alzheimer’s disease or Wilson’s disease, probably through its involvement in the production of reactive oxygen species. [ 4 ] Considering its multifaceted physiological functions, many techniques including atomic fluorescence spectrometry (AFS) [ 5 ] , atomic absorption spectroscopy (AAS) [ 6 ] , high performance liquid chromatography (HPLC) [ 7 ] and ion‐coupled plasma mass spectrometry (ICP‐MS) [ 8 ] , have been reported for detection of trace amounts of Cu 2+ in biological systems. Although these methods can quantitatively detect Cu 2+ , the instruments required are expensive, the detection process is complicated, and detection conditions are destructive to biological samples.…”

New electrochemical sensor with the renewable silver annular band working electrode: Fabrication and application for determination of selenium(IV) by cathodic stripping voltammetry

“…Total Se concentration in natural waters usually does not exceed 1 μgL −1 , but in some reports concentrations of selenium up to 400 μgL −1 are noted [3]. Today, many methods provide necessary sensitivity required for speciation analyses of selenium in waters [3][4][5][6][7]. Differential pulse cathodic stripping voltammetry (DPCSV) was used according to the method proposed by Baltensperger and Hertz [8] to measure the concentration of Se(IV), the only electrochemically active species.…”