Arsine Research Articles

Exploring the Selective Generation of Arsenic Hydrides in Quaternary Ammonium Salt Suspension: A Didactic and Systematic Qualitative Approach Applied to Wastewater Treatment

Exploring the Selective Generation of Arsenic Hydrides in Quaternary Ammonium Salt Suspension: A Didactic and Systematic Qualitative Approach Applied to Wastewater Treatment

Ag-containing metal organic framework reacted with AsH3: Mechanism and application for inorganic arsenic detection by hydride generation-smartphone RGB readout colorimetric system.

The reaction mechanism of Ag-containing metal organic framework (Ag-BTC) and hydrogen arsenide (AsH3) was discussed in detail in this work. Silver ions in Ag-BTC were reacted with AsH3, and silver nanoparticles were generated on the surface of Ag-BTC, causing its color changed. This property was further applied to a hydride generation-colorimetric analytical system. As(III) was converted to AsH3via hydride generation and then reacted with the Ag-BTC (immobilized on test paper), leading to the test paper changed from white to black. Visual colorimetric and smartphone RGB readout mode were used for this analytical system. The results could be readout by naked-eye in visual colorimetric mode and a smartphone in RGB readout mode. Under the optimized conditions, As(III) concentration as low as 10μg/L and 50μg/L could be readout by smartphone and naked-eye, respectively. This method was further successful applied to As(III) determination in real samples (drinking water samples and scented tea samples), with recoveries of 91-113%.

Investigation of Heavy Metals Including Arsenic (As) Concentration in Underground Water of Agra City using Arsenic Hydride System by Atomic Absorption Spectrometer and also Application of Geo Spatial Technology

Water Plays a significant role in our life. It serves the purpose of various Human activities such as irrigation, electricity, generation, industrial production etc. Water requirement in Uttar Pradesh is continually on the rise. In India ground water is being used as raw or untreated water for 85% of the public Supply of water varies widely from region to region and country to country. The prime requirement for sustainable development of a region is its water quality especially underground water. To check groundwater and sort out the contaminated region is economically very significant for the development of the area...Currently the potable water woes are global problem. This paper focuses on the ground water contamination of Agra city. It was selected for its importance as a popular tourist destination worldwide. The large number of tourists coming here use its water, therefore it is imperative that its water quality be monitored regularly. The present study is of mid-monsoon season 2018. For these 15 samples were collected using handheld GPS from randomly selected stations from different wards having easy access for regular sampling. The drinking water in Agra city is assessed for the following 8 parameters namely, pH, conductance, total dissolved solids (TDS) and heavy metals like Cu, Cr, Zn, Pb and As. and it is found that the concentration of various parameters is not within the permissible limit of water quality prescribed by WHO and CPCB. A GIS database of the measured spatial and water quality data is developed using QGIS3.2 and ground water quality maps are also prepared which will be helpful in monitoring the ground water quality of the status of the study area.

Atomization of As and Se volatile species in a dielectric barrier discharge atomizer after hydride generation: Fate of analyte studied by selected ion flow tube mass spectrometry

Atomization of hydrides and their methylated analogues in a dielectric barrier discharge (DBD) plasma atomizer was investigated. Selected ion flow tube mass spectrometry (SIFT-MS) was chosen as a detector being capable of selective detection of non-atomized original volatile species allowing thus direct quantification of atomization efficiency. Selenium hydride (SeH2) and three volatile arsenic species, namely arsenic hydride (AsH3), monomethylarsane (CH3AsH2) and dimethylarsane ((CH3)2AsH), were selected as model analytes. The mechanistic study performed contributes to understanding of the atomization processes in atomic absorption spectrometry (AAS). The presented results are compatible with a complete atomization of arsenic hydride as well as its methylated analogues and with atomization efficiency of SeH2 below 80%. Using AsH3 as a model analyte and a combination of AAS and SIFT-MS detectors has revealed that the hydride is not atomized, but decomposed in the DBD atomizer in absence of hydrogen fraction in the carrier gas. Apart from investigation of analyte atomization, the SIFT-MS detector is capable of quantitative determination of water vapor content being either transported to, or produced in the atomizer. This information is crucial especially in the case of the low-power/temperature DBD atomizer since its performance is sensitive to the amount of water vapor introduced into the plasma.

“Ars sine scientia” or rather “Ars sine geometria”? The debate of 1400 on the elevation of Milan cathedral

The construction of Milan Cathedral from 1386 was one of the most important episodes in the history of Italian and European architecture because of the uniqueness of the building itself — the largest Gothic church ever constructed in Italy — and because of the presence of some of the most authoritative architects of the late Fourteenth and Fifteenth centuries in Europe (Lombard, French, German).The documentation about the discussions on how to build the Duomo in the late Trecento and early Quattrocento, especially on the structural choices to be made and the different Lombard and Northern building-site practices, made famous to English readers in a celebrated article by James Ackerman, is extraordinarily rich and extensive, permitting considerations on the relationship between medieval architectural ideals and an actual project.The paper focuses on the famous discussions of 1400, in part a re-run of those of 1392. It will be argued that famous criticism by the French expert Jean Mignot of Milanese architects involving the terms ars and scientia could have a very different meaning from the one generally accepted in the literature. Consequently, it will result that Mignot wanted to return to the original project proposed by Gabriele Stornaloco, which embodied the desired correspondence between the sacred architecture and the perfect God’s world.All of which, could be of some interest to medievalists in general, and to those concerned with architectural theory and with the relationship between Gothic architecture and literature in particular.

A novel gas liquid separator for direct sampling analysis of ultratrace arsenic in blood sample by hydride generation in-situ dielectric barrier discharge atomic fluorescence spectrometry

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 KBH4 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 H2 orderly. Under the optimized conditions, the linearity ranged from 0.05 to 50 ng/mL with a regression coefficient (R2) = 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.

Atomization of arsenic hydride in a planar dielectric barrier discharge: Behavior of As atoms studied by temporally and spatially resolved optical emission spectrometry

The excitation mechanism of arsenic atoms in a planar shaped dielectric barrier discharge (DBD) atomizer with sputtered grid shaped electrodes was studied by optical emission spectrometry (OES) with resolution in time and space. Due to the shape of the electrodes, the DBD design provides optical access to the plasma not only in end-on position but also in side-on direction. By means of an iCCD camera with nanosecond time resolution coupled to a monochromator it was shown that the spatial and temporal development of the plasma emission depends on the discharge gas nature (Ar, He). Applying argon, a dense and constricted plasma filament is formed, whereas in helium a much more homogeneous plasma is ignited. The impact of both plasmas on the emission signal of arsenic atoms was studied employing analyte introduction via hydride generation. The excitation of arsenic temporally follows the emission signal of helium or argon and is spread across the whole discharge volume. The basic discharge propagation dynamics showed similarities to previously presented results obtained by OES in a capillary DBD.

Non-chromatographic Speciation of Inorganic Arsenic in Rice by Hydride Generation Inductively Coupled Plasma Optical Emission Spectrometry

Simple, straightforward non-chromatographic method for inorganic arsenic (i-As) determination in rice using species-selective hydride generation (HG) combined with inductively coupled plasma optical emission spectrometry (ICP OES) without prior separation of methylated organoarsenicals (o-As) before measurements was developed and fully validated. i-As [As(III,V)] and o-As (DMA, MMA) species were extracted in aqua regia that oxidized As(III) to As(V), while integrity of both o-As forms was preserved. Arsenic hydrides from i-As were generated in reaction with NaBH4 (1%) in strong acidic conditions (10 mol L−1 HCl) after pre-reduction of As(V) to As(III) in a KI (0.5%)-ascorbic acid (2%)-HCl (3 mol L−1) mixture. Reactivity of As species toward HG under conditions of a rice matrix was investigated in order to improve detectability and selectivity of i-As when o-As coexists. Interferences related to contribution of DMA and MMA to the As signal recorded for i-As were pointed out. Limitations of the method for DMA and matrix effects for MMA were found advantageous to selectively measure i-As by HG-ICP OES. No matrix effects on i-As allowed to use external calibration for its quantification. Detection limit of 0.28 ng g−1 (5.6 ng g−1 in original sample), precision < 5%, and adequate accuracy (96.5–103.9%), verified by the analyte recovery study, were achieved. Applicability of the method was demonstrated by i-As determination in nine brown rice samples. Its concentrations found along with the percentage of i-As to total As (obtained after microwave digestion and HG-ICP OES detection) were similar with these reported for this type of rice.

Self-Assembled Nanocomplex for Co-Delivery of Arsenic-Retinoic Acid Prodrug into Acute Promyelocytic Leukemia Cells.

The synergistic effect of arsenic (As) and all-trans retinoic acid in acute promyelocytic leukemia (APL) has been well documented. However, several major issues impeding the efficient delivery of these drugs for APL therapy remain unsolved. The low solubility of retinoic acid in physiological solutions makes drug delivery cumbersome, and the high systemic cytotoxicity of arsenic trioxide leads to unwanted side effects. In the present study, a new organo-arsenic molecule was synthesized via template-directed ring-opening esterification of an epoxy arsenic hydride (2-chloro-1,3,2-dioxaarsolane, CDA) under a nucleophilic attack exposing the hydroxyl terminus. The additional single step conjugation with retinoic acid (RA) and polyethylene glycol (PEG) yielded the amphiphilic prodrug PEG-As-RA that readily self-assembles into nanoparticles in the aqueous phase. The assembled nanoparticles containing both arsenic and RA exhibit high water solubility and good biocompatibility. In addition, they are highly stable in physiological buffers and are efficiently taken up by human APL cells. In vivo imaging results showed that the nanoparticles are characterized by prolonged blood circulation, and release both RA and As via hydrolysis to provide combination therapy for human APL. This novel organo-arsenic molecule conjugated with RA offers a new approach to the treatment of APL.

«Ars sine scientia nihil est»

Even though a tradition of work is devoted to the definition «Ars sine scientia nihil est» (the art without science is nothing- S.T., 1, 14, 8 c: Scientica autem artificis est causa artificiatorum; eo quod artifex operatur per suum intellectum) words of the Parisian architect Jean Mignot pronounced during the construction of the Milan Cathedral in 1398, a question may arise: What is the rhetorical admissible rate of construction that does not invalidate the role of architecture or that empties it of meaning? This essay is divided into four points that are paradigmatic of the relationship between technical expression, building expertise, and figurative invention. With this choice some intuitions about a specific building tradition are tested by comparison with the design established practices and some experimentation, particularly significant with respect to the relationship between emancipation and constructive figuration instance.

In-situ trapping arsenic hydride on tungsten coil and comparing interference effect of some hydride forming elements using different types of atomizers

Hydride generation atomic absorption spectrometry (HGAAS) with different types of atomizers (flame heated quartz T-tube and W-coil) was evaluated for comparison of interference effects of some hydride forming elements for arsenic determination. W-coil was used as an on-line atomizer or as a trapping surface. Mutual interferences of Sb(III), Se (IV), Sn (II) and Te(IV) on arsenic signal were compared with flame heated quartz T-tube atomizer and W-coil; on-line atomization and in-situ trapping modes. When W-coil was operated at on-line atomization mode the interference magnitudes could not be improved as much as expected with respect to quartz T-tube atomizer. However, decent improvements were achieved for interference magnitudes of each interferent species with in-situ trapping on iridium coated W-coil. Under optimized conditions and using 60s trapping period (sample volume 6ml), the limit of detection was found as 0.03ngml−1 and the calibration was linear in between 0.25–4.0ngml−1 As. The precision of the analytical method was less than 2.5% in terms of RSD (n=11) for 1.0ngml−1 arsenic concentration. The accuracy of the method was tested with certified reference materials; fortified water TMDA 61 (NWRI) and waste water EU-L-1 (SCP). The results were in a good agreement with the certified values at 95% confidence level.

Ultrasensitive and Simultaneous Determination of Arsenic and Antimony in Clinical Samples by Atomic Fluorescence Spectrometry

The determination of trace elements in human fluids facilitates the identification of metabolic disorders and physiological abnormities in clinical diagnosis. Elemental concentrations in serum, urine, and saliva are often low and highly prone to contamination. Consequently, a simple and ultrasensitive detection technique is required. In this study, a method was developed for the simultaneous determination of trace arsenic and antimony in clinical samples by hydride generation atomic fluorescence spectrometry. The experimental parameters that affect the generation, delivery, and atomization of volatile arsenic and antimony hydrides were investigated. The limits of quantification were calculated to be 0.0037 nanogram per milliliter and 0.0070 nanogram per milliliter for arsenic and antimony, respectively. The method was successfully applied for the analysis of fortified human serum, urine, saliva, and certified reference materials. The results obtained by the reported method were not statistically different from the certified values at the 95 percent confidence level.

Determination of Trace Arsenic Content in Commercial Crispbread by Hydride Generation Inductively Coupled Plasma Optical Emission Spectrometry

Methodology for the determination of total As in crispbread by hydride generation inductively coupled plasma optical emission spectrometry (HG–ICP–OES) was evaluated. The effect of pre-reduction reagents before the HG reaction under conditions of real samples was investigated. Sonication (15 min, 25°C) of samples with aqua regia allowed complete release of As species in solutions. Arsenic hydride was generated in the reaction with NaBH4 (1.0 % (m/v)) after the pre-reduction of AsV to AsIII with ascorbic acid (1.5 % (m/v)) and KI (0.5 % (m/v)) in 3 mol L–1 HCl. Detection limits (LODs) of 0.46 (AsIII) and 0.49 (AsV) μg L–1 were assessed. The accuracy of the method was confirmed by analysis with a certificate reference material and recovery test. Various crispbreads (wheat, rye, corn, rice) were analysed with the developed procedure and As content varied between 0.027 and 0.219 μg g–1, being the highest in the rice samples.

A report of 24 cases of acute hydrogen arsenide poisoning

急性砷化氢中毒主要引起急性血管内溶血及急性肾衰竭,同时伴有肝、心脏等功能损害,临床表现凶险.若不及时抢救,死亡率达20％～30％[1].我院自2008年1月至2011年12月共收治24例急性砷化氢中毒患者,经持续应用小剂量多巴胺(2 μg/kg/min),同时予激素(甲强龙)、碳酸氢钠、呋塞米和还原型谷胱甘肽综合治疗,疗效满意.1.一般资料:2008年1月至2011年12月我院共收治急性砷化氢中毒患者24例,其中男性18例,女性6例,年龄21～48岁,平均34.5岁.接触砷化氢气体时间0.5～4.0 h,发病后8～24 h入院治疗.依据GBZ 44-2002《职业性砷化氢中毒诊断及分级标准》诊断为轻度中毒10例,重度中毒14例。

Visual detection of arsenic using hydride generation followed by reaction with silver bis(2-ethylhexyl)dithiocarbamate retained in a support filter.

In this study, a simple and effective method for the detection of trace amounts of arsenic in water samples was developed. Arsenic hydride generated by the reduction of a water sample was passed through a sensing filter retaining silver bis(2-ethylhexyl)dithiocarbamate complex. The original yellow color of the filter immediately turned reddish violet. The difference of color was observed by a reflection spectrophotometer. Sensing filters made of glass fiber gave the highest sensitivity. Addition of low volatile amines effectively stabilized the performance of the sensing filter. Common anions including phosphate ion did not interfere with the arsenic detection. Visual detection of 10 μg dm(-3) was achieved in φ10 mm filter area using 60 cm(3) of sample solution.

Determination of arsenic in chilli and tomato grown in North East Thailand

Heavy metals in edible fruits constitute a health hazard. We present an analytical procedure for determining inorganic arsenic (As) species in hot chilli pepper and tomato fruits at the red-ripe stage using microwave assisted digestion (MAD) followed by flow injection-hydride generation atomic absorption spectrometry (FI-HGAAS). The optimum conditions for the acid digestion method and arsenic hydride (AsH3) determination were studied in detail. The plant sample (0.5 g) was digested with 5 ml of concentrated nitric acid by MAD programmed at 900 W for 35 min. Arsenite, As(III), in the acid digests could only be analysed by FI-HGAAS using 1% (v/v) HCl as a carrier solution and 0.5% (w/v) NaBH4 in 0.04% (w/v) NaOH as a reducing agent, while total As content was determined after pre-reduction of arsenate, As(V), to As(III) with 2% (w/v) thiourea prior to measurement. The concentration of As(V) was then calculated as the difference between total As and As(III). Detection limits for As(III) and As(V) were 0.004 and 0.006 µg/l, respectively. The relative standard deviation of the data was less than 5% (n = 10). The recovery of the samples spiked with 10 µg/l As was 98-103%. The proposed method was applied to determine traces of As in six varieties of hot chilli pepper (0.55-0.88 µg/g As(III) and 0.22-0.93 µg/g As(V)) and seven varieties of tomato (0.36-0.64 µg/g As(III) and 0.22-0.60 µg/g As(V)) samples.

Analysis of the damage of acute arsine poisoning on respiratory system

砷化氢为高毒气体,除强烈的溶血作用外,对全身各组织器官都有极强毒性.急性重度砷化氢中毒的病例报告近年并不少见[1],但有关呼吸系统损害的报道则较少.现将2005年10月至2011年1月我科收治的12例资料完整的砷化氢中毒患者出现呼吸系统损害的临床资料报告如下.一、临床资料1.一般资料:12例砷化氢中毒患者分别来自于3起事故,其中8例中毒发生于某金属研究所试验工段(工作流程为硬锌矿石+稀硫酸搅拌生成硫酸锌),4例发生于作业环境中矿渣意外接触到废酸.患者均为男性,年龄22～42岁.既往均体健,无呼吸系统疾病史,发病前无其他有害气体接触史。

Computational Modelling of the Volatile Hydride Fragmentation in a Dielectric Barrier Discharge Atomizer

In this study, we present a model whereby a fragmentation of arsenic hydride in a rectangular dielectric barrier discharge (DBD) atomizer is investigated. The aim is to elucidate the distribution of the intermediates species and generated free analyte atoms along atomizer channel, which is required to decide the optimal position for spectrometric data acquisition. Simulation results indicate that formation of intermediate species and free arsenic atoms is initiated in the first section of atomization channel before reaching the section between the electrodes. Moreover, concentration of free arsenic atoms saturates to a maximum and does not vary thereafter along atomization channel. This result could be attributed to the presence of abundance of hydrogen radicals along atomization channel which limits recombination reactions and ultimately maintains free atom life, which is so useful for analytical purposes. This outcome suggests an approach for radial data acquisition from any position along DBD atomization channel with same sensitivity. Furthermore, this result indicates that DBD atomizer is appropriate for analytical purposes and competitive to other well known atomization tools such as a quartz cell atomizer. The model has been verified experimentally upon examining arsenic and mercury qualitatively from applying chemical vapour generation techniques. Approximately similar results obtained from three radial positions along the atomization channel, whereas a significant increase in signal intensity observed when applying axial viewing by 22 and 40% for arsenic and mercury respectively. Furthermore, a quantitative determination for arsenic is also tried; however, the results were found not useful for model validation due to the hydrogen magnification effect on the recorded spectrum.

Fundamental Investigation of Chemical Mechanical Polishing of GaAs in Silica Dispersions: Material Removal and Arsenic Trihydride Formation Pathways

The fabrication of InGaAs n-channels in CMOS devices requires an intervening buffer layer of GaAs or InP between a Si substrate and the InGaAs channel layer, which has to be planarized to enable the growth of a channel that is free of defects due to uneven surface topography. This report discusses the material removal rates (RRs) and AsH3 evolution observed during chemical mechanical polishing (CMP) of GaAs using aq. solutions of hydrogen peroxide (H2O2) and silica slurries containing H2O2. GaAs RRs were negligible with deionized water or with silica slurries alone. They were relatively high in aq. solutions of H2O2 alone and showed a strong pH-dependence, with significantly higher RRs in the alkaline region. The addition of silica particles to aq. H2O2 did not increase the GaAs RRs significantly. The evolution of arsenic trihydride (AsH3) during the dissolution of GaAs in aq. H2O2 solution was similarly higher in the basic pH range than in neutral pH or in the acidic pH range. However, no AsH3 was measured during polishing, evidently because of the relatively high water solubility of AsH3. In this report, GaAs removal rates and AsH3 formation are analyzed using data from contact angle measurements, X-Ray photoelectron spectroscopy (XPS), and X-Ray fluorescence (XRF) spectroscopy. Reaction pathways leading to material removal are proposed.

Formation of arsenolite crystals at room temperature after very high dose arsenic implantation in silicon

Spontaneous growth of arsenolite micro-crystals at room temperature after high fluence, low energy arsenic trihydride implantation in silicon was observed on the wafer surface after exposure to air. The crystals have been identified unambiguously by x-ray absorption and fluorescence spectroscopy. Thermal treatment easily sublimates the crystals at temperatures as low as 200 °C without any relevant in-diffusion of As into the substrate. The deposition of a thin As-rich layer under high fluence implantation conditions is suggested as possible precursor for crystal formation. The same layer can explain the anomalous retained dose increase often observed after annealing.