Low-cost field test kits for arsenic detection in water
01 Jan 2014-Journal of Environmental Science and Health Part A-toxic\/hazardous Substances & Environmental Engineering (J Environ Sci Health A Tox Hazard Subst Environ Eng)-Vol. 49, Iss: 1, pp 108-115
TL;DR: Though the kits were meant for qualitative assay, the results with unknown concentrations of real samples, when compared with atomic absorption spectrophotometer (AAS) were in good agreement as revealed by the t-test.
Abstract: Arsenic, a common contaminant of groundwater, affects human health adversely. According to the World Health Organization (WHO), the maximum recommended contamination level of arsenic in drinking water is 10 μg/L. The purpose of this research was to develop user-friendly kits for detection of arsenic to measure at least up to 10 μg/L in drinking water, so that a preventive measure could be taken. Two different kits for detection of total arsenic in water are reported here. First, the arsenic in drinking water was converted to arsine gas by a strong reducing agent. The arsine produced was then detected by paper strips via generation of color due to reaction with either mercuric bromide (KIT-1) or silver nitrate (KIT-2). These were previously immobilized on the detector strip. The first one gave a yellow color and the second one grey. Both of these kits could detect arsenic contamination within a range of 10 μg/L-250 μg/L. The detection time for both the kits was only 7 min. The kits exhibited excellent performance compared to other kits available in the market with respect to detection time, ease of operation, cost and could be easily handled by a layman. The field trials with these kits gave very satisfactory results. A study on interference revealed that these kits could be used in the presence of 24 common ions present in the arsenic contaminated water. Though the kits were meant for qualitative assay, the results with unknown concentrations of real samples, when compared with atomic absorption spectrophotometer (AAS) were in good agreement as revealed by the t-test.
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08 Jul 2015
TL;DR: In this article, the authors highlight the need for better portable arsenic contamination detection, and describe how microfluidic technology may be developed to address this need, and comment on their potential for portable microfluidity adaptation.
Abstract: Arsenic contamination of drinking water is a major global problem, with contamination in Bangladesh deemed most serious. Although the current World Health Organisation (WHO) maximum contamination limit (MCL) for arsenic in drinking water is 10 μg L−1, due to practical and economic constraints, the standard limit in Bangladesh and many other developing nations is 50 μg L−1. We propose that an ideal arsenic sensor, designed for routine monitoring, will have five essential qualities: sensitivity and selectivity for arsenic; speed and reliability; portability and robustness; reduced health and environmental risks; and affordability and ease of use for local technicians. It is our opinion that many of these characteristics can be accentuated by microfluidic systems. We describe candidate colorimetric, electrochemical, biological, electrophoretic, surface-sensing, and spectroscopic methods for arsenic detection; and comment on their potential for portable microfluidic adaptation. We also describe existing developments in the literature towards the ultimate creation of microfluidic total analysis systems (μTASs) for arsenic detection. The fundamental purpose of this review is to highlight the need for better portable arsenic contamination detection, and describe how microfluidic technology may be developed to address this need.
99 citations
TL;DR: A paper-based microfluidic device is fabricated that can rapidly detect very low concentrations of As3+ ions using a gold nanosensor, Au-TA-TG as discussed by the authors.
Abstract: A paper based microfluidic device is fabricated that can rapidly detect very low concentrations of As3+ ions using a gold nanosensor, Au–TA–TG. This simple but efficient system develops a visible bluish-black colour precipitate due to the formation of nanoparticle aggregates through transverse diffusive mixing of Au–TA–TG with As3+ ions on a paper substrate. The approach is extremely selective for arsenic with a detection limit of 1.0 ppb, which is lower than the WHO's reference standard for drinking water.
90 citations
TL;DR: RJB-2 owing to its intrinsic abilities of plant growth promotion even in presence of high concentrations of arsenic could inhibit arsenic uptake completely and therefore it could be used in large-scale cultivation for phytostabilization of plants.
84 citations
TL;DR: The iridium(iii) complex 1 was synthesized and employed in constructing an assay which is based on a G-quadruplex for detecting arsenic ions in aqueous solution and showed high selectivity towards arsenic ions over other metal ions.
Abstract: In this work, the iridium(iii) complex 1 was synthesized and employed in constructing an assay which is based on a G-quadruplex for detecting arsenic ions in aqueous solution. The assay achieved a detection limit of 7.6 nM (ca. 0.57 μg L-1) and showed high selectivity towards arsenic ions over other metal ions. Additionally, the assay could function in natural water and a simple microfluidic chip was used to investigate the potential of this platform for real-time detection.
49 citations
TL;DR: This work implements a system that compares the concentration of two signal molecules, and tunes GFP expression proportionally to their relative abundance, performed via molecular titration between an orthogonal σ factor and its cognate anti-σ factor.
Abstract: In many biotechnological applications, it is useful for gene expression to be regulated by multiple signals, as this allows the programming of complex behavior. Here we implement, in Escherichia coli, a system that compares the concentration of two signal molecules, and tunes GFP expression proportionally to their relative abundance. The computation is performed via molecular titration between an orthogonal σ factor and its cognate anti-σ factor. We use mathematical modeling and experiments to show that the computation system is predictable and able to adapt GFP expression dynamically to a wide range of combinations of the two signals, and our model qualitatively captures most of these behaviors. We also demonstrate in silico the practical applicability of the system as a reference-comparator, which compares an intrinsic signal (reflecting the state of the system) with an extrinsic signal (reflecting the desired reference state) in a multicellular feedback control strategy.
48 citations
References
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TL;DR: The development of substitute materials for arsenic applications in the agricultural and forestry industries and controls of arsenic emissions from the coal industry may be possible strategies to significantly decrease arsenic pollution sources and dissipation rates into the environment.
Abstract: Arsenic, a carcinogenic trace element, threat- ens not only the health of millions of humans and other living organisms, but also global sustainability. We present here, for the first time, the global industrial-age cumulative anthropogenic arsenic production and its potential accumulation and risks in the environment. In 2000, the world cumulative industrial-age anthropogenic arsenic production was 4.53 million tonnes. The world- wide coal and petroleum industries accounted for 46% of global annual gross arsenic production, and their overall contribution to industrial-age gross arsenic production was 27% in 2000. Global industrial-age anthropogenic As sources (as As cumulative production) follow the order: As mining production >As generated from coal >As generated from petroleum. The potential industrial-age anthropogenic arsenic input in world arable surface in 2000 was 2.18 mg arsenic kg �1 , which is 1.2 times that in the lithosphere. The development of substitute materials for arsenic applications in the agricultural and forestry industries and controls of arsenic emissions from the coal industry may be possible strategies to significantly decrease arsenic pollution sources and dissipation rates into the environment.
160 citations
"Low-cost field test kits for arseni..." refers background in this paper
...The presence of arsenic in drinking water is due to either its natural presence in surface and in groundwaters,[2] or as a result of human activities such as industrial applications,[3] leather and wood treatments,[4] use of pesticides....
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TL;DR: For countries such as Bangladesh with a significant groundwater arsenic problem, there is an urgent need for the arsenic-contaminated wells to be identified as soon as possible and for appropriate action to be taken, and field-test kits offer the only practical way forward.
144 citations
"Low-cost field test kits for arseni..." refers methods in this paper
...Most of the field test kits for detection of arsenic in water available in the market utilized Gutzeit method.[16,17] This involves generation of arsine gas (AsH3) by reduction of arsenic using zinc and hydrochloric acid....
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01 Jan 1973
TL;DR: In this paper, analytical results for 166 samples collected during 1960-65 from 89 geysers, pools, and hot springs are compiled together with previous analyses to provide a comprehensive collection of aV'ailable analytical data on the thermal waters of Yellowstone National Park, Wyo.
Abstract: Analytical results for 166 samples collected during 1960-65 from 89 geysers, pools, and hot springs are compiled together with previous analyses to provide a comprehensive collection of aV'ailable analytical data on the thermal waters of Yellows·tone National Park, Wyo. These data permit further study of the variation of composition with time or geologic occurrences. Data are presented for pH, temperature, silica, aluminum, iron, calcium, magnesium, sodium, potassium, lithium, ammonia, bicarbonate, carbonate, sulfate, chloride, fluoride, boron, arsenic, and the semiquantitative spectrographic analysis of residues from evaporation of some of the waters. The chemical characteristics of waters from V'arious localities in Yellowstone are graphically compared and discussed. INTRODUCTION Extensive chemical analyses of waters from hot springs and geysers in Yellowstone National Park have been reported by Gooch and Whitfield (1888) and by Allen and Day (1935). Scott (1964) analyzed ten thermal waters from Yellowstone to determine possible effects of the nearby Hebgen Lake, Montana, earthquake of August 17, 1959, upon the hydrothermal system. White, Hem, and Waring (1963) reported six new chemical analyses and Noguchi and Nix (1963) published partial chemical analyses of waters from five geysers. Field measurements of silica dissolved in the hot-springs waters were reported by White, Brannock, and Murata (1956) and by Morey, Fournier, Remley, and Rowe (1961). The new results reported here and the compilation of previous analyses are part of an effort by the U.S. Geological Survey to reevaluate the geology and geochemistry of Yellowstone. We are indebted to many colleagues in the Survey who have contributed to this study, especially to D. E. White for his advice
65 citations
"Low-cost field test kits for arseni..." refers background in this paper
...The generated arsine can be quantified by trapping it either in a silver diethyldithiocarbamate solution,[18] or on paper impregnated with mercuric bromide, [19] both of which act as a detector element....
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TL;DR: In this paper, a simple, rapid and selective colorimetric visualization of arsenic using unmodified gold nanoparticles (AuNPs) and a phytochelatin-like peptide (γ-Glu-Cys)3-GlyArg (denoted as PC3R) was presented.
Abstract: In this paper, we report a simple, rapid and selective colorimetric visualization of arsenic using unmodified gold nanoparticles (AuNPs) and a phytochelatin-like peptide (γ-Glu-Cys)3-Gly-Arg (denoted as PC3R). Arsenic prevented the peptide from attaching to the surface of AuNPs by coordinating to all the three cysteine residues of PC3R, thus preventing the PC3R-triggered AuNPs aggregation and color change. The present approach is selective to arsenic detection and is much faster and simpler than the conventional analytical methods. The detection limit is 20 nM, which is lower than the World Health Organization's (WHO) standard for drinking water. The feasibility for the detection of arsenic in groundwater has also been demonstrated. This method will be valuable for the design of new types of metal ions sensors and will likely lead to many colorimetric detection applications in environmental monitoring.
47 citations
"Low-cost field test kits for arseni..." refers methods in this paper
...Xia et al.[14] developed a colorimetric assay for detection of arsenite using gold nanoparticles and a phyto-chelatin-like peptide....
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...Xia et al.[14] developed a colorimetric assay for detection of arsenite...
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TL;DR: A simple and sensitive method based on the formation of micro particles of Ethyl Violet and molybdoarsenate, which gives an apparently homogeneous blue color to the solution, enabling the spectrophotometric determination of arsenic with the detection limit of 4 microg l(-1).
Abstract: In this study, a simple and sensitive method for the determination of arsenic in water samples was developed. The method is based on the formation of micro particles of Ethyl Violet and molybdoarsenate, which gives an apparently homogeneous blue color to the solution. The absorption of the excess dye gradually decreases due to its conversion to a colorless carbinol species under strongly acidic conditions. Consequently, the sufficiently low reagent blank enables the spectrophotometric determination of arsenic with the detection limit of 4 microg l(-1). The coefficient of variation for the spectrophotometry at 50 microg l(-1) was 3.5% (n = 5). Furthermore, it is possible to detect concentrations as low as 10 microg l(-1) of arsenic visually. Our method will be useful as a simple, rapid, and cost-effective field test of arsenic, requiring no complex apparatus or skilled laboratory support.
47 citations
"Low-cost field test kits for arseni..." refers methods in this paper
...Most of the field test kits for detection of arsenic in water available in the market utilized Gutzeit method.[16,17] This involves generation of arsine gas (AsH3) by reduction of arsenic using zinc and hydrochloric acid....
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