Novel Dielectric Barrier Discharge Trap for Arsenic Introduced by Electrothermal Vaporization: Possible Mechanism and Its Application

Abstract

In this work, a novel integrated dielectric barrier discharge (IDBD) reactor coupled to an electrothermal vaporizer (ETV) was established for arsenic determination. It is for the first time gas-phase enrichment (GPE) was fulfilled based on the hyphenation of ETV and DBD. The mechanisms of evolution of arsenic atomic and molecular species during vaporization, transportation, trapping, and release processes were investigated via X-ray photoelectron spectroscopy (XPS) and other approaches. Tentative mechanisms were deduced as follows: the newly designed DBD atomizer (DBDA) tube upstream to the air inlet fulfills the atomization of arsenic nanoparticles in vaporized aerosol, leading to free arsenic atoms that are indispensable for forming arsenic oxides; the DBD trap (DBDT) tube traps arsenic oxides under an O 2 -domininating atmosphere and then releases arsenic atoms under H 2 -dominating atmospheres. In essence, this process is a physical−chemical process rather than an electrostatic particle deposition. Such a trap and release sequence separates matrix interference and enhances analytical sensitivity. Under the optimized conditions, the method detection limit (LOD) was 0.04 mg/kg and the relative standard deviations (RSDs) were within 6% for As standard solution and real seafood samples, indicating adequate analytical sensitivity and precision. The mean spiked recoveries for laver, kelp, and Undaria pinnatifida samples were 95−110%, and the results of the certified reference materials (CRMs) were consistent with certified values. This ETV-DBD preconcentration scheme is easy and green and has low cost for As analysis in seafood samples. DBD was proved a novel ETV transportation enhancement and preconcentration technique for arsenic, revealing its potential in rapid arsenic analysis based on direct solid sampling ETV instrumentation.

Atomic spectrometry update: review of advances in the analysis of clinical and biological materials, foods and beverages

“…Recoveries of 20 mg kg −1 spikes ranged from 103% to 114%. Gu et al 119 trapped the As species, generated by decomposition of slurried seafood samples with a tungsten coil vaporiser, on a DBD device, but then released the species into an AF spectrometer for quantification. The LOD was an unimpressive 40 μg kg −1 (probably because of the extensive dilution of the slurry sampling step) and the method was validated by the analysis of three CRMs GBW08521 (laver) GBW10023 (laver) and GBW10024 (scallop) and applied to the analysis of three real samples that were also analysed by ICP-MS, for which samples were pretreated by MAD.…”

Atomic spectrometry update: review of advances in atomic spectrometry and related techniques

“…Gu et al 77 used tungsten coil ETV for sample introduction of As into a DBD trap , under an O 2 atmosphere, then release of As atoms in to a H 2 atmosphere. They used XPS to deduce that atomisation of As nanoparticles in the vaporised aerosol formed As atoms that then formed As oxides.…”

Ultrasonic Nebulization-Accelerated Gas-Phase Enrichment Following In Situ Microplasma Desorption for Analysis of Trace Heavy Metals by Optical Emission Spectrometry

“…In contrast, gas-phase enrichment (GPE) is more convenient, which can retain the merits of VG and simply convert the signal of low-concentration analyte in a long period of time into that of rapid release of accumulatively trapped analyte. At present, GPE methods have involved in thermal trapping using the graphite furnace, quartz tube or metal materials, cryotrapping at liquid nitrogen temperature, dielectric barrier discharge (DBD) trapping, , and headspace solid-phase microextraction (HS-SPME). , In the thermal trapping and cryotrapping, the necessity of a temperature-controlled trap/release procedure usually complicates device and process design. DBD trapping and HS-SPME are more preferred, which are carried out under ambient temperature.…”

“…In contrast, gas-phase enrichment (GPE) is more convenient, 15 trapped analyte. At present, GPE methods have involved in thermal trapping using the graphite furnace, 16 quartz tube 17 or metal materials, 18 cryotrapping at liquid nitrogen temperature, 19 dielectric barrier discharge (DBD) trapping, 20,21 and headspace solid-phase microextraction (HS-SPME). 22,23 In the thermal trapping and cryotrapping, the necessity of a temperature-controlled trap/release procedure usually complicates device and process design.…”