Trace Amounts Of Arsenic Research Articles

Synthesis, characterization and As(III) scavenging behaviours of mango peel waste loaded with Zr(IV) ion from contaminated water

Raw mango peel (RMP) was first saponified to yield saponified mango peel (SMP), which was then loaded with Zr(IV) ions to form a biosorbent for As(III) scavenging.The biosorption behaviors and mechanisms of As(III) scavenging using RMP and Zr(IV)-loaded saponified mango peel (Zr(IV)-SMP) were investigated batchwise. The As(III) scavenging efficiency of RMP increased from 20.13 % to 87.32 % after Zr(IV) loading. Optimum contact time of 6 h has been investigated for As(III) scavenging by Zr(IV)-SMP, and the data on kinetics is well fitted to the pseudo-second-order (PSO) model. Similarly, isotherm data of Zr(IV)-SMP fitted well to the Langmuir isotherm model with the maximum As(III) scavenging potential of 45.52 mg/g. Chloride (Cl−) and nitrate (NO3−) have negligible influence on As(III) scavenging, but sulphate (SO42−) interferes significantly. The exhausted Zr(IV)-SMP could be easily regenerated by treating with 2MNaOH. A mechanistic study indicates that As(III) scavenging is primarily contributed to electrostatic interaction and ligand exchange, which is confirmed from both instrumental and chemical characterizations techniques. Tubewell underground water polluted with a trace amount of arsenic (98.63 μg/L) could be successfully lowered down to the WHO standard (10 μg/L) by applying a small amount of Zr(IV)-SMP. Therefore, the Zr(IV)-SMP investigated in this work can be a low-cost, environmentally benign, and promising alternative for scavenging trace levels of arsenic from contaminated water.

Assessment on the Physicochemical and Phytochemical Properties, Nutritional and Heavy Metal Contents, and Antioxidant Activities of Hylocereus polyrhizus Peel from Northern Philippines

Background/Objectives: In the Philippines, Hylocereus polyrhizus is gaining upsurge interest due to its potential health benefits. Aside from the edible fruit pulp, various products from its peel are being developed, and claimed as health boosters. Thus, this study was conducted to assess the physicochemical characteristics, phytochemical constituents, nutritional and heavy metal contents and antioxidant activity of the peel of H. polyrhizus. Methods/Statistical analysis: Physicochemical and phytochemical screening were conducted following established protocols. Nutritional value and trace metals were measured with food analytical standard methods. Antioxidant activity was estimated using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing capacity (FRC) assays. Statistical analyses were carried out for DPPH and FRC assays using Graph-Pad Prism. Findings: Results showed that H. polyrhizus peel contains alkaloids, coumarins, flavonoids, phenols, and triterpenoids. Trace amounts of arsenic (0.022 mg/kg), lead (0.887 mg/kg), cadmium (0.068 mg/kg) and chromium (0.225 mg/kg) were detected which were all within the acceptable limit set by the WHO for herbal materials. H. polyrhizus peel contained 6.72% moisture, 14.7% ash, 0.526% total fat, 0.226% saturated fat, 3.73% total sugar, 4.28% crude protein, 73.8% total carbohydrate, and 63.2% total dietary fiber. Other nutrients detected are macronutrients such as K > Ca > Mg > Na, micronutrients Mn > Fe, and Vitamin C. Moreover, it exhibited remarkable antioxidant activity in terms of FRC assay and DPPH assay (IC50 = 986.8mg/mL). The present study results showed that H. polyrhizus peel could be used as a potentially rich source of nutrients and natural antioxidants. Thus, it can be developed as an ingredient for food and health products. Novelty/Applications: The preliminary data obtained provide information that could support the development of products from dragon fruit peel. The conversion of these wastes into utilizable natural health products would help in reducing environmental problems Ma. Danica Ines Ramil et al. / Indian Journal of Science and Technology 2021;14(14):1097–1104 associated with processing waste disposal. Keywords: Antioxidant; Dragon Fruit Peel; Hylocereus polyrhizus; Phytochemical Screening; Nutritional Content; Heavy Metals

Soft tissue measurement of arsenic and selenium in an animal model using portable X-ray fluorescence

Abstract The ingestion of trace amounts of arsenic (As) through drinking water is a relatively common pathway of exposure with potentially serious long-term health effects. Studies involving animal models have indicated that selenium (Se) may bind with As inside the body and facilitate excretion. A portable X-ray fluorescence (XRF) technique was previously developed to allow in vivo measurement of As and Se in human tissue. In the current paper, this portable XRF approach was tested for the first time using animal tissue. Seven female Lakeview Golden/LVG Syrian hamsters were dosed under either control, As-only, Se-only, or As and Se conditions. Minimum XRF detection limits in soft tissue of 1.00±0.05 ppm for As and 0.83±0.02 ppm for Se were determined from phantom calibration trials. For dosed hamsters, consistently higher concentrations of As and Se were found in the liver and gall bladder, with elevated levels also observed in the intestines. Concentrations ranged up to 26.4±1.4 ppm for As and 11.8±0.8 ppm for Se. The stomach and heart exhibited more moderate concentrations, while the brain, lung, and muscle demonstrated lower levels. For a given organ, As concentrations generally exceeded Se concentrations. A ratio of approximately 2.5:1 was observed for concentrations of As:Se when considering the same or similar tissue sites in dosed hamsters. Implications for potential in vivo human applications of the technique are briefly considered.

Technological study of the gilded haft-rang tiles of the Imamzadih Ismail mausoleum in Qazvin, Iran

Gilding decorations on Islamic tiles have been previously studied either historically or technologically. The major emphasis in these studies has always been focused on the use of gold leaf on glazed tiles. The current research has been conducted by electron probe micro-analysis (EPMA), portable micro X-ray fluorescence (μ-XRF), scanning electron microscopy (SEM), optical microscopy and atomic force microscopy (AFM) to shed light on a less-known technique of gilding applied on the nineteenth century haft rang glazed tiles of the Imamzadih Ismail mausoleum in Qazvin, Iran. Our observations showed that the gilding decorations are performed on a blue alkali glaze. Plant ash was suggested to be the source of alkali and cobalt was identified as the colouring agent of the glaze. Moreover, trace amounts of arsenic in the composition of the blue glaze was interpreted to be associated with the colouring agent of the glaze; i.e., cobalt. Furthermore, the gilding decorations were suggested to be achieved by firing gold powder on the pre-fired blue substrate glaze. AFM, SEM and optical microscopy proved that the gold flakes partially penetrated the pre-fired blue substrate glaze. This paper established a local provenance for the colouring agent of the blue glaze used as a substrate of gilding decorations. In addition, our studies showed that the gilding decorations were achieved by firing gold powder on the pre-fired blue glaze of a nineteenth century Persian haft rang tile.

Absence of detectable arsenate in DNA from arsenate-grown GFAJ-1 cells.

A strain of Halomonas bacteria, GFAJ-1, has been claimed to be able to use arsenate as a nutrient when phosphate is limiting and to specifically incorporate arsenic into its DNA in place of phosphorus. However, we have found that arsenate does not contribute to growth of GFAJ-1 when phosphate is limiting and that DNA purified from cells grown with limiting phosphate and abundant arsenate does not exhibit the spontaneous hydrolysis expected of arsenate ester bonds. Furthermore, mass spectrometry showed that this DNA contains only trace amounts of free arsenate and no detectable covalently bound arsenate.

GFAJ-1 Is an Arsenate-Resistant, Phosphate-Dependent Organism

The bacterial isolate GFAJ-1 has been proposed to substitute arsenic for phosphorus to sustain growth. We have shown that GFAJ-1 is able to grow at low phosphate concentrations (1.7 μM), even in the presence of high concentrations of arsenate (40 mM), but lacks the ability to grow in phosphorus-depleted (<0.3 μM), arsenate-containing medium. High-resolution mass spectrometry analyses revealed that phosphorylated central metabolites and phosphorylated nucleic acids predominated. A few arsenylated compounds, including C6 sugar arsenates, were detected in extracts of GFAJ-1, when GFAJ-1 was incubated with arsenate, but further experiments showed they formed abiotically. Inductively coupled plasma mass spectrometry confirmed the presence of phosphorus in nucleic acid extracts, while arsenic could not be detected and was below 1 per mil relative to phosphorus. Taken together, we conclude that GFAJ-1 is an arsenate-resistant, but still a phosphate-dependent, bacterium.

Interlaboratory Bias and Uncertainty in the Analysis of Metals and Polychlorinated Biphenyls in Used Oil Samples

Abstract Blank and used oil samples spiked with PCBs at two different concentrations and heavy metals were sent to various analytical laboratories based upon national reputation, recognition, and applicable accreditation (EPA or NELAC). The study, implemented in a double-blind manner, was designed to simulate a client sending actual used oil samples to a certified laboratory for the quantitative analysis of PCBs and heavy metals for regulatory purposes. The study was also designed for comparing and contrasting the reported results in a statistically meaningful manner. The primary purpose of the study was to assess the accuracy and precision of each of the laboratories. Sending multiple, double-blind samples of the same mixture allowed an estimate of uncertainty to be determined. A large bulk sample (∼10 L) of used crankcase oil was prepared. From this base of used oil, spiked bulk samples were prepared. A bulk sample composed of 2 mg/kg 1260 PCBs and a bulk sample composed of 50 mg/kg 1260 PCBs were prepared. Additionally, a bulk sample spiked with 5 mg/kg arsenic, 2 mg/kg cadmium, 10 mg/kg chromium, and 100 mg/kg lead was prepared. From these unspiked and spiked bulk samples, aliquots were poured into specialty containers certified to be free of trace metals and organic compounds. The aliquoted samples were then sent to ten different laboratories across the United States for the quantitative determination of PCBs and trace toxic heavy metals. For the analysis of blank oil samples, one laboratory reported values an order of magnitude lower relative to the other laboratories for most of the metals. These results were disregarded. Two laboratories reported detecting trace amounts of arsenic in the blank oil samples. The remaining laboratories reported the values below their reporting limits. There was fairly good agreement across the laboratories for the analysis of chromium. With leads, however, the laboratories could be grouped into three statistically different groups. The spiked oil results indicated that laboratories could be grouped into statistically similar groups based upon individual metals. The lack of a grouping pattern across metals indicate the grouping to be metal-specific and hence, the differences in the laboratories may be the result of some unknown random process that cannot be directly measured. Regarding the analysis of PCBs spiked at 2 mg/kg, there was relatively good agreement across laboratories in that most could not quantitate PCBs at this level. At the regulatory level of 50 mg/kg, 33 % of the laboratories could not detect the PCBs. Across the measured values at the regulatory limit, a very significant amount of variation was observed, in agreement with earlier observations. In an attempt to account for these differences, as the factors responsible for the variances are not known, a random effect paradigm is introduced along with a gaming strategy based upon a time-constant model.

A New Spectrophotometric Method for the Determination of Arsenic in Environmental and Biological Samples

A simple and selective spectrophotometric method has been developed for the determination of trace amounts of arsenic using azure B as a chromogenic reagent. The proposed method is based on the reaction of arsenic(III) with potassium iodate in acid medium to liberate iodine. The liberated iodine bleaches the violet color of azure B and is measured at 644 nm. This decrease in absorbance is directly proportional to the As(III) concentration, and Beer's law is obeyed in the range 0.2–10 µg ml−1 of As(III). The molar absorptivity, Sandell's sensitivity, detection limit, and quantitation limit of the method were found to be 1.12×104 l mol−1cm−1, 6.71×10−3 µg cm−2, 0.02 µg ml−1 and 0.08 µg ml−1, respectively. The optimum reaction conditions and other analytical parameters were evaluated. The proposed method has been successfully applied for the determination of arsenic in various environmental and biological samples.

Arsenic determination in naphtha by electrothermal atomic absorption spectrometry after preconcentration using multiple injections

Naphtha is a petroleum fraction containing C4–C15 hydrocarbon compounds and is used as feedstock for petrochemical processes which are affected profoundly by trace amounts of arsenic. A simple method for arsenic determination in naphtha using electrothermal atomic absorption spectrometry with polarized Zeeman-effect background correction was developed. Multiple injections were used for direct preconcentration in the graphite tube, eliminating sample pretreatment. Doehlert experimental designs were used to find the best settings for the furnace program parameters. Modifier concentration, number of multiple injections and sample volume were also optimized with the same multivariate approach. With three 45 µL sample injections, ashing temperature 1200 °C, atomization temperature 2700 °C and ashing time 60 s, a detection limit of 0.5 µg L−1 and a characteristic mass of 61 pg were achieved, using 3000 mg L−1 Pd(NO3)2 as the chemical modifier. The relative signal standard deviation was found to be 9.0% at the 2.3 µg.L−1 level. Results from several naphtha test samples showed arsenic levels typically below 3.0 µg L−1. The high degree of automation of the proposed method minimized technician sample handling allowing its application for routine analysis. This procedure has been used for arsenic determination in naphtha feeds processed in the Braskem Petrochemical (Salvador, Bahia, Brazil).

Assessment of cancer risk and environmental levels of arsenic in New Hampshire

AbstractThe Agency for Toxic Substances and Disease Registry (ATSDR) and the United States (US) Environmental Protection Agency (EPA) Office of Solid Waste and Emergency Response (OSWER) list arsenic as a major concern for Superfund sites and the environment at large. Arsenic is clearly linked to skin, bladder, and lung cancer occurrence in populations highly exposed to arsenic occupationally, medicinally, or through contaminated drinking water (Agency for Toxic Substances and Disease Registry, 1999; IARC, 1987). While these studies have identified important adverse health effects, they cannot provide risk information at lower levels of exposure such as those commonly found in the US. Additionally, precise measurement of exposure is critical to assessing risk in populations consuming relatively trace amounts of arsenic. In New Hampshire, domestic wells serve roughly 40% of the population, and about 10% of these contain arsenic concentrations in the controversial range of 10 to 50 μg/l. New Hampshire, along with other states in New England, has among the highest bladder cancer mortality rates in the country. Therefore, we are conducting a population-based epidemiologic study in New Hampshire (1) to assess the risk of skin and bladder cancer associated with arsenic exposure in a US population, (2) to evaluate methods of quantifying individual exposure to arsenic at low to moderate levels, and (3) to explore alternative models of determining the dose-response relationship at the lower end of exposure. Our findings to date indicate that toenail arsenic concentrations are a reliable, long-term biomarker of total arsenic exposure and reflect arsenic intake by drinking water containing 1 μg/l or more. We found that urinary arsenic cannot be detected consistently in a population for which drinking water arsenic is primarily below 50 μg/l. Lastly, our data suggest that use of a biologic marker along with alternative statistical approaches may aid detection of the levels at which arsenic may affect cancer occurrence in the US.

Treatment Chemicals Contribute to Arsenic Levels

This article discusses how testing source water alone may not be sufficient to determine the arsenic load in finished water. Some treatment chemicals may also contain trace amounts of arsenic. Methods for computing the trace arsenic concentrations in finished water that are contributed by treatment chemicals are given, along with tables tabulating information produced by several calculations.

Determination Of Arsenic In Various Environmental And Oil Samples By Differential Pulse Polarography After Adsorption Of Its Morpholine-4-Carbodithioate On To Microcrystalline Naphthalene Or Morpholine-4-Dithio-Carbamate-Ctmab-Naphthalene Adsorbent

ABSTRACT A highly selective, sensitive, rapid and economical differential pulse-polarographic (DPP) method has been developed for the quantitative determination of trace amounts of arsenic in various environmental and crude oil samples. The morpholine-4-carbodithioate of arsenic was quantitatively adsorbed on microcystalline naphthalene in the pH range of 6.0–9.5. The metal complex alongwith naphthalene was shaken with 10 ml of 1 M HCl and arsenic determined with a differential pulse polarograph using HCl-pyridine-NaCl as the supporting electrolyte. Arsenic may also be adsorbed quantitatively under similar conditions on morpholine-4-dithiocarbamate-cetyltrimethylammonium bromide-naphthalene adsorbent packed in a column at a flow rate of 0.5–5.0 ml/min and determined similarly. The detection limit is 0.016 ppm at the minimum instrumental setting (signal to noise ratio=2). Arsenic is being determined in the concentration range of 0.08–9.0 ppm with a correlation factor of 0.9996 and a relative standard deviation of ±0.81% (n=8). Various parameters such as the effect of pH, volume of aqueous phase, and interference of a number of metal ions and anions on the estimation of arsenic have been evaluated to optimise the conditions for the estimation of arsenic in various environmental and crude oil samples.

Determination of arsenic, selenium and mercury in an estuarine sediment standard reference material using flow injection and atomic absorption spectrometry

A flow-injection analysis atomic absorption spectrometric (FIA-AAS) method was developed for the determination of trace amounts of arsenic, selenium and mercury in a proposed estuarine sediment standard reference material (SRM 1646a). The samples were prepared in two manners: a) A wet digestion procedure with HNO3, H2SO4, and HClO4 using a reflux column and b) A microwave-oven digestion procedure utilizing HNO3, H2SO4, and HCl for As and Se, and HNO3 for Hg. Microwave-oven digestion provides results comparable to those found by reflux column digestion and reduces the sample preparation time by a factor of 10. The proposed method employing the microwave-oven digestion procedure coupled with FIA-AAS for As and Se, and FIA-CVAAS for Hg, has detection limits of 0.15 ng As/ml, O.17 ng Se/ml and 0.15 ng Hg/ml.

Continuous hydride generation low-pressure microwave-induced plasma atomic emission spectrometry for the determination of arsenic, antimony and selenium

The direct coupling of on-line continuous hydride generation methods to low-pressure microwave-induced Ar and He plasmas, sustained in a surfatron, was evaluated for the determination of trace amounts of arsenic, antimony and selenium by atomic emission spectrometry. The effect of the hydrogen produced during the hydride generation step, the optimization of the operating conditions for He and Ar plasmas and the figures of merit of the analytical systems are given. Detection limits (3s) of 0.7, 0.9 and 4.1 ng ml–1 were obtained for As, Sb and Se, respectively, using an Ar plasma at 50 Torr (1 Torr = 133.322 Pa) and a power of 115 W. The relative standard deviations, calculated at the 50 ng ml–1 level, were in the range 3–4% for the three elements. Poorer detection limits were obtained for He than for Ar discharges (by about two to five times, depending on the emission line). Using an argon discharge, the method was applied successfully to the determination of As in sea-waters.

Simultaneous determination of trace concentrations of arsenic, antimony and bismuth in soils and sediments by volatile hydride generation and inductively coupled plasma emission spectrometry

Trace amounts of arsenic, antimony and bismuth in soils and sediments are determined simultaneously by an inductively coupled plasma-volatile hydride method after rapid attack with concentrated hydrochloric acid in sealed tubes. The samples are treated with the acid at 150 °C for 2 h in capped test-tubes. After addition of potassium iodide solution, the hydrides are formed by mixing the solution with sodium tetrahydroborate(III) solution in a continuous-flow system, and are swept into the plasma by a stream of argon for determination by atomic-emission spectrometry. Acceptable precision and accuracy are obtained, and the detection limits for all three analytes are about 0.1 µg g–1. Approximately 200 samples can be analysed by one person in a 2-d cycle.

A modification of the heteropoly blue method for the microgram determination of arsenic in biological materials

A sensitive method has been developed for analysis of trace amounts of arsenic in biological materials using the heteropoly blue method. The method employs a closed apparatus and a nitrogen atmosphere, and allows the detection of arsenic in ppm concentration using samples of 100 mg.

On the Tissue Distribution and the Excretion of Arsenic in Rats and Rabbits of Administration with Arsenical Compounds

Distribution of arsenic in blood and tissues, and excretion of arsenic in feces and urine after an oral administration of arsenic trioxide (29 mg/kg) or methylarsine sulfide (36 mg/kg) were examined in rats and rabbits. Blood level of arsenic in rats reached the maximum 3 days after a single administration of arsenic trioxide, and decreased at a slow biological half-life of 60 days, but blood concentration of arsenic in rabbits was about 1/80 of that in rats 24 hr after dosing. Distribution of arsenic in rat tissues attained the maximum 2 days, but its content was only 1% of the administered dose. Excretion of arsenic in rat feces was 68.6% during the first 4 days and a trace amount of arsenic was detected in bile. Fecal excretion of arsenic in rabbits was 62.9% and 36.2% during 7 days, respectively, when arsenic trioxide and methylarsine sulfide were given. On the other hand, urinary excretion of arsenic in the rat was only 1.8% of the dose during 30 days after arsenic trioxide administration, but the level of arsenic in rabbit urine was 5.5% and 18.2%, respectively, during 7 days after arsenic trioxide and methylarsine sulfide treatment.

Methylarsine Sulfide : Its Tissue Distribution, Excretion, and Effects on the Liver Constituents and Drug Metabolizing Enzyme System

After an oral administration of 18 mg/kg of methylarsine sulfide, the distribution of arsenic in blood and tissues, the excretion of arsenic in feces and urine, its effect on liver constituents including microsomal phospholipids and cytochromes, and drug-metabolizing enzyme activities were examined. The blood level of arsenic reached the maximum 3 days after dosing and decreased at a slow biological half-life of 50 days. The distribution of arsenic in tissues also attained the maximum at 3 days and more than 2 % of the dose was found at 120 days. Excretion of arsenic in feces was 33.4% during the first 4 days and a trace amount of arsenic was detected in bile. The urinary excretion of arsenic was about 7% of the dose during the first 3 days, 18% during 30 days, and still remained at 120 days. Methylarsine sulfide reduced the cytochrome P-450 content, aminopyrine demethylase activity, and spectral change with aniline binding. Enzyme activities per P-450 were not changed. In hepatic microsomal phospholipids, the percentage composition remained unchanged but the total content and the percentage of unsaturated fatty acids decreased by the effect of methylarsine sulfide.

A Remarks on Determination of Trace Amount of Arsenic in Oils, Fats and Waxes

To determine trace amount of arsenic in oils, fats and waxes, these materials are used to be burnt to ashes or saponified with caustic soda solution befor hand. In the latter case, too much amount of arsenic is frequently determined due to unfavorable arsenic extracted from glass vessels by the caustic soda solution. In this paper, some instructions to eliminate this analytical error are mentioned.The saponification must be carried out in a vessel of quartz, pyrex glass, polytetrafluoroethylene, or stainless steel. The caustic soda solution also must be prepared by using these vessels and stored in a bottle of plastics, such as polyethylene.