Photochemical Vapor Generation of Tellurium: Synergistic Effect from Ferric Ion and Nano-TiO₂

Abstract

Photochemical vapor generation (PVG) is emerging as a promising analytical tool for Te determination, thanks to its efficient matrix separation, and simple and green procedure. However, the low PVG generation efficiency of Te is the bottleneck for its wide application in environmental samples containing trace Te. Herein, we reported a high efficient PVG for Te determination by synergistic effect of ferric ion and nano-TiO. The analytical sensitivity was enhanced approximately 15-fold for Te(IV) in the presence of both ferric ions and nano-TiO, comparing to conventional PVG. Besides, the use of nano-TiO can provide Te(VI) and Te(IV) an equal and high PVG efficiency in the presence of ferric ions, owned to the high photocatalytic performance of TiO under short-wavelength UV irradiation (254 and 185 nm). Under the optimized experimental conditions, a detection limit of 1.0 ng L was obtained. The precision of replicate measurements was 2.3% (RSD, n = 7) at 0.5 μg L for Te(IV). The methodology was validated by successful determination of Te in surface waters and two standard reference sediment samples. To our best knowledge, this is the first report of the synergistic enhancement of transitional metal ions and nano-TiO in PVG, which possesses potential for highly sensitive determination of vapor-forming elements.

Reduction of Interferences Using Fe-Containing Metal–Organic Frameworks for Matrix Separation and Enhanced Photochemical Vapor Generation of Trace Bismuth

“…Previous studies show that metal ions may work as homogeneous sensitizers for the photochemical reduction of elements. The addition of metal ions (such as Fe, Cu, Co, and Ni) into PVG medium may enhance the PVG efficiency, accelerate the kinetic reaction, as well as improve the analytical precision of analytes. ,,,,, Nevertheless, severe interferences from concomitant metal ions were observed for the PVG of analytes, making the direct quantification by external calibration method troublesome. For example, the addition of Fe 3+ into PVG media can provide a 12-fold enhancement in PVG response of Bi 3+ .…”

“…For Pb determination, an approximately four thousand times improvement in analytical sensitivity was obtained with multicollector–inductively coupled plasma mass spectrometry (MC-ICPMS) measurement using nickel-assisted PVG . Hereafter, transition-metal-ion-enhanced PVG has been found for the analysis of Hg, As, Se, Te, Mo, Bi, Ir, Cl, and Rh, leading to a 1.4- to 4130-fold enhancement in analytical sensitivity. − Nevertheless, the interferences from the coexisting ions, especially for other transition ions, on the direct and accurate determination of analytes are obvious. ,,, Therefore, standard addition or isotope dilution methods are usually required for the accurate analysis of samples with a complicated matrix, resulting in the relatively low sample throughput.…”

Enhanced Photochemical Vapor Generation for the Determination of Bismuth by Inductively Coupled Plasma Mass Spectrometry

“…The PVG photoreactor was interfaced to the ICP MS as reported before (Figure ). The PVG reactor, providing 185 and 254 nm irradiation, was a 19 W thin film flow-through lamp (Beijing Titan Instruments Co., Beijing, China), which was loosely covered by aluminum foil to protect the operator from UV irradiation. A tandem set of two gas–liquid separators for the separation of volatile Bi from sample solution (GLSs, ∼ 2 mL internal volume) was immersed in an ice bath to minimize any transport of liquid droplets derived from the condensation of water vapor or coexisting volatile organic compounds to the ICP torch.…”

“…The signal response has been enhanced from 1.6- to 4130-fold for the determination of Hg, As, Pb, Cl, Se, and Te in the presence of transitional metal ions (Table S1). ,,,− Metal ion-enhanced PVG has been successfully applied for the determination of analytes in environmental samples with satisfying results. However, the field is not sufficiently developed and still at the beginning stage.…”

Facile route for porous N,S co‐doped TiO 2 nanoparticles for visible light‐driven photocatalysis

“…To tackle the issues mentioned above, various methods including morphologies controlling [4], the ions doping [5], decoration with noble metal particles [6], crystal growth design [7], and hetero structuring [8] have been introduced. Among these methods, non‐metal elements doping have been proved to be helpful in the reduction of bandgap of TiO 2 and made it favourable to use visible light [9].…”