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At present, immediate monitoring urinary arsenic is still a challenge for treating arsenic poisoning patients. Thus, a fast, reliable and accurate analytical approach is indispensable to monitor ultratrace arsenic in urine sample for health warning. In this work, a silicon nitride (SN) rod was first integrally utilized as a sample carrier for ≤50 μL urinary aliquot, an electric heater for removing water and ashing sample as well as a high voltage electrode for dielectric barrier discharge vaporization (DBDV). The direct analytical method of arsenic in urine without sample digestion was thus developed using atomic fluorescence spectrometer (AFS) as a model detector. After 4 V electrically heating the SN rod for 60 s, urine sample was dehydrated and ashed outside; then, DBD was exerted under 0.8 A with 0.8 L/min H 2  + Ar (1:9, v:v) for 20 s to vaporize arsenic analyte from the SN rod. After optimization, 0.014 μg/L arsenic detection limit (LOD) was reached with favorable analytical precision (RSD <5%) and accuracy (91-110% recoveries) for real sample analysis. As a result, the whole analysis process only consumes <3 min to exclude complicated sample preparation; furthermore, the designed DBDV system only occupies 25 W and <2 kg, which renders a miniature sampling component to hyphenate with a miniature detector to detect arsenic. Thus, this direct sampling DBDV method extremely fulfills the fast, sensitive and precise detection of ultratrace arsenic in urine sample., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

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.

In this work, a novel method using low-cost miniaturized hydride generation optical emission spectrometry equipment coupled with an in situ dielectric barrier discharge trap (HG- in situ DBD trap-OES) was established for the determination of As in edible seaweed samples. An improved peak volume algorithm, where the start time point and end time point of the spectrum at each concentration are determined according to the unified judgment criteria, was first proposed to extend the linear range from 1-100 μg L -1 to 1-200 μg L -1 , and increase the sensitivity by about 30%. In addition, a modification was done on the DBD implementation, providing an enhancement of sensitivity by a factor of about 4 for As. All in all the detection limit (LOD) was improved from 0.5 μg L -1 to 0.2 μg L -1 . By applying the method to seaweed samples, a method detection limit (MD) of 0.25 mg kg -1 was achieved, with less than 3% relative standard deviations (RSDs). The calibration linearity reached R 2 > 0.990 in the 1.25-250 mg kg -1 range. Results obtained by the proposed method showed good agreement with that of certified reference materials (CRMs), and spiked recoveries were 103% to 114%, indicating favorable accuracy. The proposed method is attractive in terms of instrumentation size (0.6 m × 0.5 m × 0.3 m), power consumption (<60 W), manufacturing cost, and gas consumption (300 measurements for 4 L compressed Ar/H 2 gas), and therefore more advantageous than conventional atomic spectrometric methods.

A novel direct sampling (DS-HG) system consisting of an enlarged gas liquid separator (GLS) coupled with a foam breaker was firstly utilized for the in-situ dielectric barrier discharge atomic fluorescence spectrometer (DBD-AFS). After direct dilution using 5% HCl (v:v), a prepared blood sample was introduced into the DS-HG with a UV digestion unit, of which arsenic hydrides directly generated from sample under 5% HCl (v:v) and 5 g/L KBH 4 in 1.5 g/L KOH. Herein, the newly designed DS-HG is capable of effectively eliminating foam generation deriving from protein in blood sample. Then, arsenic hydrides were trapped by 11 kV discharging at 110 mL/min air, and released by 13 kV at 180 mL/min H 2 orderly. Under the optimized conditions, the linearity ranged from 0.05 to 50 ng/mL with a regression coefficient (R 2 ) = 0.996. The method detection limit (LOD) was 7 pg arsenic (0.14 ng/mL), and relative standard deviation (RSD) of 10 repeated measurements for a real blood sample was 4.2%, indicating a good precision. The spiked recoveries for real samples were in the range of 97%-102%. Furthermore, arsenic presence in real blood samples measured by the proposed method were consistent (P > 0.05) with the microwave digestion ICP-MS. The whole analytical time can be controlled within 8 min including sample dilution. As a matter of fact, it is a favorable progress for DBD technique to eliminate matrix interferences of real samples based on the gas phase enrichment (GPE) principle, with advantages such as excellent sensitivity, digestion-free, fast and simple operation. Thus, the recommended DS-HG-in-situ DBD-AFS are suitable to the fast analysis of ultratrace arsenic in blood samples to protect human's health., (Copyright © 2019. Published by Elsevier B.V.)

The mechanisms of arsenic gas phase enrichment (GPE) by dielectric barrier discharge (DBD) was investigated via X-ray photoelectron spectroscopy (XPS), in situ fiber optic spectrometer (FOS), etc. It proved for the first time that the arsenic species during DBD trapping, release, and transportation to the atomic fluorescence spectrometer (AFS) are probably oxides, free atoms, and atom clusters, respectively. Accordingly, a novel in situ DBD trap as a GPE approach was redesigned using three-concentric quartz tube design and a modified gas line system. After trapping by O 2 at 9.2 kV, sweeping for 180 s, and releasing by H 2 at 9.5 kV, 2.8 pg detection limit (LOD) was achieved without extra preconcentration (sampling volume = 2 mL) as well as 4-fold enhancement in absolute sensitivity and ∼10 s sampling time. The linearity reached R 2 > 0.998 in the 0.1-8 μg/L range. The mean spiked recoveries for tap, river, lake, and seawater samples were 100-106%; and the measurements of the certified reference materials (CRMs) were in good agreement with the certified values. In situ DBD trap is also suitable to atomic absorption spectrometry (AAS) or optical emission spectrometry (OES) for fast and on-site determination of multielements.

Accurate, stable and fast analysis of toxic inorganic arsenic (iAs) in complicated and arsenosugar-rich algae matrix is always a challenge. Herein, a novel analytical method for iAs in algae was reported, using bromine halogenation and on-line nonpolar solid phase extraction (SPE) followed by hydride generation atomic fluorescence spectrometry (HG-AFS). The separation of iAs from algae was first performed by nonpolar SPE sorbent using Br - for arsenic halogenation. Algae samples were extracted with 1% perchloric acid. Then, 1.5mL extract was reduced by 1% thiourea, and simultaneously reacted (for 30min) with 50μL of 10% KBr for converting iAs to AsBr 3 after adding 3.5mL of 70% HCl to 5mL. A polystyrene (PS) resin cartridge was employed to retain arsenicals, which were hydrolyzed, eluted from the PS resin with H 2 O, and categorized as iAs. The total iAs was quantified by HG-AFS. Under optimum conditions, the spiked recoveries of iAs in real algae samples were in the 82-96% range, and the method achieved a desirable limit of detection of 3μgkg -1 . The inter-day relative standard deviations were 4.5% and 4.1% for spiked 100 and 500μgkg -1 respectively, which proved acceptable for this method. For real algae samples analysis, the highest presence of iAs was found in sargassum fusiforme, followed by kelp, seaweed and laver., (Copyright © 2017 Elsevier B.V. All rights reserved.)

A novel dielectric barrier discharge reactor (DBDR) was utilized to trap/release arsenic coupled to hydride generation atomic fluorescence spectrometry (HG-AFS). On the DBD principle, the precise and accurate control of trap/release procedures was fulfilled at ambient temperature, and an analytical method was established for ultratrace arsenic in real samples. Moreover, the effects of voltage, oxygen, hydrogen, and water vapor on trapping and releasing arsenic by DBDR were investigated. For trapping, arsenic could be completely trapped in DBDR at 40 mL/min of O2 input mixed with 600 mL/min Ar carrier gas and 9.2 kV discharge potential; prior to release, the Ar carrier gas input should be changed from the upstream gas liquid separator (GLS) to the downstream GLS and kept for 180 s to eliminate possible water vapor interference; for arsenic release, O2 was replaced by 200 mL/min H2 and discharge potential was adjusted to 9.5 kV. Under optimized conditions, arsenic could be detected as low as 1.0 ng/L with an 8-fold enrichment factor; the linearity of calibration reached R(2) > 0.995 in the 0.05 μg/L-5 μg/L range. The mean spiked recoveries for tap, river, lake, and seawater samples were 98% to 103%; and the measured values of the CRMs including GSB-Z50004-200431, GBW08605, and GBW(E)080390 were in good agreement with the certified values. These findings proved the feasibility of DBDR as an arsenic preconcentration tool for atomic spectrometric instrumentation and arsenic recycling in industrial waste gas discharge.

A new atomizer based on atmospheric pressure dielectric barrier discharge (DBD) plasma was specially designed for atomic fluorescence spectrometry (AFS) in order to be applied to the measurement of arsenic. The characteristics of the DBD atomizer and the effects of different parameters (power, discharge gas, gas flow rate, and KBH(4) concentration) were discussed in the paper. The DBD atomizer shows the following features: (1) low operation temperature (between 44 and 70 degrees C, depending on the operation conditions); (2) low power consumption; (3) operation at atmospheric pressure. The detection limit of As(III) using hydride generation (HG) with the proposed DBD-AFS was 0.04 microgL(-1). The analytical results obtained by the present method for total arsenic in reference materials, orchard leaves (SRM 1571) and water samples GBW(E) 080390, agree well with the certified values. The present HG-DBD-AFS is more sensitive and reliable for the determination of arsenic. It is a very promising technique allowing for field arsenic analysis based on atomic spectrometry.

An ultrasonic assisted slurry sampling procedure was coupled with hydride generation in-situ dielectric barrier discharge trap optical emission spectrometry (HG-in situ DBD trap-OES) to provide the simple and fast determination of arsenic in soil. The soil was treated HNO3 and HF in an ultrasonic bath for 25 min, subsequently diluted with 6% HCl (v/v) and 40 g L−1 thiourea, and placed into the ultrasonic bath again for 10 min to obtain a stable and homogeneous slurry that was introduced to HG-in-situ DBD trap-OES for As determination. Under the optimal conditions, the calibration coefficient exceeded 0.995 from 2 μg L−1 to 200 μg L−1. A method detection limit of 0.18 mg kg−1 was achieved for As in soil (250 times dilution) with a 3.4% relative standard deviation. The developed method was validated by the determination of As in three soil certified reference materials including GBW07430 (As, 18 ± 2 mg kg−1), GBW07447 (As, 10.7 ± 0.5 mg kg−1), and GBW07449 (As, 8.7 ± 0.6 mg kg−1), as well as two real soil samples. The results agreed well with the certified values and the measurements by inductively coupled plasma – mass spectrometry. With advantages of simple pretreatment procedures, small size/weight, low power consumption, and low manufacturing cost, the developed method has the potential to be widely applied in soil analysis. [ABSTRACT FROM AUTHOR]

In this work, an in situ dielectric barrier discharge trap (DBDT) was first utilized to preconcentrate inorganic arsenic (iAs) species coupled with liquid chromatography hydride generation atomic fluorescence spectrometry (LC-HG-AFS), and a novel LC-HG-in situ DBDT-AFS instrument was thereby fabricated. Considering the relatively deficient sensitivity of LC-HG-AFS and retention of As(V) in a strong anion exchange column, As(V) was chosen as a model species for iAs preconcentration. During the extraction of arsenic species in a rice sample using 1% (v/v) HNO3 and 1% (v/v) H2O2, As(III) was oxidized to As(V) being regarded as iAs. After LC separation, according to the retention time, only As(V) was trapped by 11 kV discharging under 110 mL min−1 air mixed with Ar; following sweeping by Ar gas for 190 s, iAs was released with 13 kV at 180 mL min−1 H2-rich Ar to the AFS for measurement. Via preconcentration, the limit of detection (LOD) of iAs reached 0.05 μg L−1 with ∼10 times enhancement in analytical sensitivity; the linearity (r) was > 0.997 ranging from 0.5 μg L−1 to 50 μg L−1 with 1.9% RSD (5 μg L−1, n = 6). The measured iAs in certified reference materials (CRMs) were all within their certified values, and the spike recoveries were in the range of 93–102%. With sensitivity, robustness, low power, small size and easy operation, the combination of LC and DBDT fulfilled the analysis of trace iAs in rice samples. In fact, other arsenic species can also be preconcentrated and detected to enhance the sensitivity by this proposed LC-HG-in situ DBDT technique via precisely synchronizing DBD trap and release with chromatographic retention. To focus on the food safety, iAs was chosen as a model arsenic species to verify the availability of in situ DBDT. Considering the versatility of DBD, in situ DBDT demonstrates a promising application for elemental speciation analysis and LC atomic spectrometry. [ABSTRACT FROM AUTHOR]

In this study, the slurry sampling hydride generation (SLS-HG) system was first coupled with in situ dielectric barrier discharge atomic fluorescence spectrometry (DBD-AFS) for arsenic analysis in biological samples based on the gas phase enrichment (GPE) principle. After a simple slurry dilution with 5% HCl (v/v) for microbiological and hair samples, the as-prepared slurry was introduced into the SLS-HG unit for arsine generation under 8 g L−1 KBH4 in 1.5 g L−1 KOH. Here, the in situ DBD apparatus, comprising of the three-concentric quartz tubes, was employed to pre-concentrate arsenic to enhance the analytical sensitivity of the HG-AFS, as well as to eliminate interferences due to the dilution effect and matrix separation. This was followed by trapping with 11 kV at 110 mL min−1 of air carrier gas, and 190 s Ar gas sweeping, arsenic was released with 13 kV at 180 mL min−1 H2 to the AFS for measurement. Under optimal conditions, 8 pg or 14 pg detection limits (2 mL sampling) for the microbiological or hair samples were achieved without extra pre-concentration, respectively. The linearity R2 was 0.996 ranging from 0.05 μg L−1 to 300 μg L−1. The spiked recoveries for the real paramecium and micro diatom samples were 93–102%, and the measurements were in accordance with the certified reference material (CRM) values. The proposed SLS-HG-in situ DBD-AFS method is extremely suitable for ultratrace arsenic determination in biological samples to protect human health and environmental safety. [ABSTRACT FROM AUTHOR]

Abstract: A novel procedure was developed for the determination of arsenite (As(III)), arsenate (As(V)), monomethylarsonic (MMA) and dimethylarsinic acid (DMA) with ion chromatography–hydride generation-atomic fluorescence spectrometry (IC–HG-AFS) by employing a new gas–liquid separator (GLS). The effective separation of the four arsenic species was achieved in about 12min. With a sample loading volume of 20μl, the measurable minimum for As(III), DMA, MMA and As(V) were 0.02, 0.045, 0.043 and 0.166ng, respectively, along with relative standard deviations of 1.1, 1.1, 1.7 and 2.2% at the 100μgl−1 level (n =6) for As(III), DMA, MMA and As(V), respectively. The present procedure was applied for the speciation of arsenic in underground water and in urine samples, and the sum of the four arsenic species by IC–HG-AFS was in good agreement with the total value by HG-AFS. [Copyright &y& Elsevier]

In this work, a portable and reliable optical emission spectrometric (OES) instrument based on solid acid hydride generation (HG) and subsequent in situ dielectric barrier discharge (DBD) preconcentration was first developed for simultaneous and field analysis of ultratrace As and Sb in environmental water. In situ DBD fulfilled both gas phase enrichment (GPE) and excitation; effective enrichment made it possible to use a low-cost charge coupled device (CCD) as detector. To simplify field protocol, solid tablet made from sulfamic acid was first used to replace hydrochloric acid for co-generation of As and Sb hydrides. Moisture interference was eliminated by carrier gas sweeping without any desiccant. After calculating peak volume for emission data handling, detection limits (LODs) were 0.5 μg L−1 for As and 0.2 μg L−1 for Sb, respectively, with <3% relative standard deviations (RSDs) at 10 μg L−1; linear dynamic ranges (R 2 >0.995) were 2–200 μg L−1 for As and 1–200 μg L−1 for Sb, respectively. The results agreed with certified values of CRMs and recoveries were 87–97% vs. inductively coupled plasma mass spectrometry. The running costs can be controlled within one dollar per use. This HG- in situ DBD trap-OES scheme, with demonstrated advantages in sensitivity, low-cost, power (<60 W), size (0.6 m × 0.5 m × 0.3 m), weight (15 kg), gas consumption (300 measurements per 4 L tank), and multi-element capability, was implemented in a miniature spectrometer for field analysis. Image 1 • In situ DBD trap was first coupled to OES for preconcentration as well as excitation. • Solid sulfamic acid was first used to replace liquid acid for hydride generation. • Moisture interference for DBD was effectively eliminated without any desiccant. • A cheap charge coupled device was employed as detector to reduce instrument cost. [ABSTRACT FROM AUTHOR]