Inorganic Arsenic Concentrations Research Articles

Validation of an analytical method for the determination of inorganic, organic, and total arsenic in fish sauce based on hydride generation atomic absorption spectrometry

An atomic absorption spectrometric (AAS) method was performed to determine the total, inorganic, and organic arsenic in fish sauce. The total organic arsenic was calculated from the total and inorganic arsenic values quantified using the hydride generation AAS (HG-AAS). Under optimal experimental conditions at the absorbance wavelength of 193.7 nm, the concentration of inorganic arsenic in fish sauce ranged from 0.05 to 1.2 mg/L, with a limit of detection (LOD) of 0.015 mg/L. The detectable total arsenic concentrations varied widely, ranging from 0.03 to 2.5 mg/L with the LOD of as low as 0.01 mg/L. The practical applicability of the method was demonstrated with the recovery in the range from 97 to 102% for inorganic arsenic, and 97 to 101% for organic arsenic. The method was applied to the analysis of commercial products from Nha Trang, Phan Thiet, and Phu Quoc City, Vietnam. The total organic arsenic in fish sauce samples determined by HG-AAS was compared with the results of liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP/MS). The f-test and t-test showed null hypothesis for acceptable variance and mean at a confidence level of 95%. The results showed that the HG-AAS method had high efficiency, accuracy, and sensitivity in quantifying inorganic and total organic arsenic in fish sauce using simple instrumentation.

Determination of Arsenic Content in Water Using a Silver Coordination Polymer.

In this report, we describe a practical method for the colorimetric determination of dissolved inorganic arsenic content in water samples, using a silver coordination polymer as the sensing material. We demonstrate that a crystalline polymer framework can be used to stabilize silver(I) ions, greatly reducing both photosensitivity and water solubility, while still affording sufficient reactivity to detect arsenic in water samples at low parts-per-billion (ppb) levels. Test strips fabricated with the silver-based polymer are shown to be effective for field tests of groundwater under real-world operating conditions and display performance that is competitive with commercially available mercury-based test strips. Spectroscopic methods are also used to probe the reaction products formed, in order to better understand the sensing mechanism. Thus, our work provides the foundation for an improved field test that could be deployed to help manage groundwater usage in regions where arsenic contamination is problematic but sophisticated lab testing is not readily available.

Determination of Inorganic Arsenic for Pet Food by LC-ICP-MS

We have developed a quantitative determination method of the concentration of inorganic arsenic in pet foods using a liquid chromatograph-inductively coupled plasma-mass spectrometer (LC-ICP-MS). After adding 2 w/v% TMAH solution to a sample, inorganic arsenic was extracted by heating and the extract was collected by water. The pH of the solution was adjusted, and injected into a LC-ICP-MS to determine the concentration of inorganic arsenic. LC separation was carried out on an ODS column with 10 mmol/L sodium 1-butanesulfonate, 4 mmol/L malonic acid, 4 mmol/L TMAH and 0.05% methanol solution as a mobile phase. A collaborative study was conducted by nine laboratories using dry and wet-type pet foods, formed jerky, dried jerky and biscuit. Dry-type pet food and dried jerky was added with 2 mg/kg of As (III). Wet-type pet food was added with 0.5 mg/kg of As (III). Formed jerky was added with 1 mg/kg of As (III). Biscuit was added with 0.2 mg/kg of As (III). The mean recoveries, repeatabilities and reproducibilities in the form of relative standard deviation (RSDr and RSDR), and HorRat, were 95.4% to 98.3%, less than 2.9%, less than 9.1%, and 0.22 to 0.51, respectively.

Provision of folic acid for reducing arsenic toxicity in arsenic-exposed children and adults.

Provision of folic acid for reducing arsenic toxicity in arsenic-exposed children and adults.

Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry for the Analysis of Complex Compounds in Serum and Its Application in Accurate Detection of Early Arsenic Exposure.

With the acceleration of industrialization, environmental arsenic pollution is threatening human health. However, by the time clinical symptoms appear, arsenic toxicity has usually caused irreversible damage to the body, so it is important to establish a rapid and accurate screening method for early arsenic exposure. In this work, 32 female C57BL/6 mice were exposed to different concentrations of inorganic arsenic in drinking water for a week. By analyzing the changes in serum, more than 20 compounds were detected to increase or decrease with the increase of arsenic intake. The abnormal increase in inosine, xanthine, xanthosine, and hypoxanthine and the abnormal purine pathway were found at the same time. Dimethylarsenic acid, an important inorganic arsenic metabolite in the body, was also found in serum. Combined with statistical analysis, early arsenic exposure can be easily and quickly detected, and the potential health risks of short-term exposure can be revealed simultaneously.

VALIDATION OF AN ANALYTICAL METHOD FOR THE DETERMINATION OF INORGANIC AND ORGANIC ARSENIC IN FISH SAUCE BY HYDRIDE GENERATION ATOMIC ABSORPTION SPECTROSCOPY

The validation of an analytical method was carried out for the determination of arsenic components in fish sauce by HG-AAS. The total arsenic content (tAs) was analyzed after digesting the sample by dry and wet combined digestion method in a Teflon flask at 450 °C and then reducing As (V) to As (III) with a mixture of reducing agents KI/ascorbic acid. For inorganic arsenic content (iAs), the sample was hydrolyzed with HCl solution for 14 hours, converted As (V) to As (III), then reacted with hydrazine 1.5%. Extracted in CHCl3 and re-extracted in HNO3. The organic arsenic content (oAs) was calculated by the difference tAs and iAs. Determined the linear concentration range 2 - 30 μg/L and the standard curve was y = 0.0128x + 0.0007 with R² = 0.9996 at the concentration range 2 - 20 μg/L. LODs, LOQs for total and inorganic arsenic contents were found and all they were 0.015 mg/L and 0.05 mg/L, respectively. For total arsenic, the recovery efficiencies on the organic arsenic standard and inorganic arsenic standard all ranged from 81 to 109%;...

The relatively higher concentrations of trace elements to arsenic may have influenced on methylation process of inorg- As in humans

The relatively higher concentrations of trace elements to arsenic may have influenced on methylation process of inorg- As in humans

Arsenic speciation in fish from Baltic Sea close to chemical munitions dumpsites

Chemical weapons that were dumped in seas and oceans after World War II, including the Baltic Sea, are sources of pollution of marine areas. Sunken containers can corrode, unseal, and numerous compounds pass into the environment, including toxic forms of arsenic, which are then taken up by marine animals. This study aims to quantify concentration of total arsenic, inorganic arsenic (III + V), and organic compounds arsenobetaine, monomethylarsonic acid, dimethylarsinic acid in the muscle tissues of cod, herring, sprat, and flounder and the associated risk to consumer health. Sprat muscle (0.636 mg kg−1) had the highest content of total arsenic, significantly less was noted in the muscles of herring (0.460 mg kg−1) and flounder (0.588 mg kg−1), and the least was in cod (0.390 mg kg−1). Toxic inorganic arsenic compounds were present in the fish tested at levels below 0.02 mgkg−1 and constituted from 3.45 to 5.75% of total arsenic. Arsenobetaine dominated among organic forms, and concentrations of it, like total arsenic, varied depending on the fish species. Consumer health risk was determined with the estimated daily intake, the target hazard quotient, and the carcinogenic risk. Estimated daily intake values for inorganic arsenic in herring, cod, sprat, and flounder were below the reference dose at 0.51 × 10−5 mg kg−1 b. w. day. The target hazard quotient factor of 0.0017 indicated there was no threat. Carcinogenic risk values were within the permissible range of 10−6 to 10−4. Current data indicate that inorganic arsenic compounds pose no risk to the health of consumers of Baltic fishes.

Regulation of transgelin and GST-pi proteins in the tissues of hamsters exposed to sodium arsenite

Regulation of transgelin and GST-pi proteins in the tissues of hamsters exposed to sodium arsenite

Does and duration of exposure time dependent regulation of proteins in the urinary bladder of hamsters exposed to sodium arsenite

Does and duration of exposure time dependent regulation of proteins in the urinary bladder of hamsters exposed to sodium arsenite

Contribution of diet and other factors for urinary concentrations of total arsenic and arsenic species: data for US children, adolescents, and adults.

A comprehensive analysis of the associations between the consumptions of 17 food products with urinary concentrations of arsenobetaine, total arsenic, arsenous acid, dimethylarsinic acid (UDMA), monomethylarsonic acid (UMMA), and total inorganic arsenic for US children aged 3-5 years (N = 439), children aged 6-11 years (N = 2139), adolescents aged 12-19 years (N = 2434), and adults aged >= 20 years (N = 10902) was conducted. Data from National Health and Nutrition Examination Survey for 2005-2016 were used for this study. Concentrations of arsenobetaine were as much as > 15 times higher among consumers of fish/shellfish than non-consumers for children aged 6-11 years, > 12 times higher for children aged 3-5 years, > 13 times higher for adolescents, and > 7 times higher for adults. Consumption of rice as opposed to non-consumption of rice was associated with as much as 36.5% higher concentrations of total arsenic, 12.7% higher concentrations of arsenous acid, 43.9% higher concentrations of UDMA, 18.2% higher concentrations of UMMA, and 14.1% higher concentrations of total inorganic arsenic. Thus, consumption of fish/shell fish and rice was associated with higher concentrations of organic/inorganic arsenic. In addition, consumption of alcohol was also found to be associated with higher concentrations of organic/inorganic arsenic. However, consumption of milk and milk products, vegetables, organ and other meats, and nutritional drinks was found to be associated with lower concentrations of organic/inorganic arsenic. Thus, while consumption of several foods is associated with higher concentrations of arsenic, there are also foods whose consumption is associated with decreased concentrations of arsenic. Further studies are needed to identify foods that may lead to decreased concentrations of arsenic and as such arsenic toxicity.

Method validation for As speciation in rice using LC-ICP-MS and the inorganic arsenic limit for Brazilian rice

A methodology for As speciation in rice using liquid chromatography-inductively coupled plasma mass spectrometry (LC-ICP-MS) was optimised and validated. Chromatographic separation and elution of As(III), DMA(V) (dimethylarsenic acid), MMA(V) (monomethylarsenic acid) and As(V) were achieved in less than 8 min using 10 mmol L−1 (NH4)2HPO4 as the mobile phase, at pH 6 and a flow rate of 1.4 mL min−1. The limits of detection for As(III), DMA(V), MMA(V) and As(V) in rice were 1.87, 2.89, 0.54 and 3.00 ng g-1, respectively. The method’s accuracy was assessed through analyte recovery tests and analysis of certified reference materials, which included white and brown rice flours. The validated method was applied for As speciation in 640 rice samples, comprising polished (white) rice, parboiled rice and brown rice collected from different mesoregions in the Rio Grande do Sul State in Brazil. By comparing the total concentration of As (tAs) found in the acid digested samples with the As species sum, the average extraction efficiencies were 98 ± 13%, 93 ± 12% and 86 ± 6%, for white, parboiled, and brown rice, respectively. The average concentrations of inorganic arsenic (iAs, that is As(III) + As(V)), DMA and tAs in brown and parboiled rice were not different but differed from those in white rice; the average concentrations of tAs, iAs and DMA in brown and parboiled rice were higher than those found in white rice were. The iAs concentration in all rice samples was lower than 200 ng g−1, which could be recommended as the maximum iAs concentration for Brazilian rice.

Grain Inorganic Arsenic Content in Rice Managed Through Targeted Introgressions and Irrigation Management.

Arsenic (As) accumulation in rice grain is a significant public health concern. Inorganic As (iAs) is of particular concern because it has increased toxicity as compared to organic As. Irrigation management practices, such as alternate wetting and drying (AWD), as well as genotypic differences between cultivars, have been shown to influence As accumulation in rice grain. A 2 year field study using a Lemont × TeQing backcross introgression line (TIL) mapping population examined the impact of genotype and AWD severity on iAs grain concentrations. The “Safe”-AWD [35–40% soil volumetric water content (VWC)] treatment did not reduce grain iAs levels, whereas the more severe AWD30 (25–30% VWC) consistently reduced iAs concentrations across all genotypes. The TILs displayed a range of iAs concentrations by genotype, from less than 10 to up to 46 μg kg–1 under AWD30 and from 28 to 104 μg kg–1 under Safe-AWD. TIL grain iAs concentrations for flood treatments across both years ranged from 26 to 127 μg kg–1. Additionally, seven quantitative trait loci (QTLs) were identified in the mapping population associated with grain iAs. A subset of eight TILs and their parents were grown to confirm field-identified grain iAs QTLs in a controlled greenhouse environment. Greenhouse results confirmed the genotypic grain iAs patterns observed in the field; however, iAs concentrations were higher under greenhouse conditions as compared to the field. In the greenhouse, the number of days under AWD was negatively correlated with grain iAs concentrations. Thus, longer drying periods to meet the same soil VWC resulted in lower grain iAs levels. Both the number and combinations of iAs-affecting QTLs significantly impacted grain iAs concentrations. Therefore, identifying more grain iAs-affecting QTLs could be important to inform future breeding efforts for low iAs rice varieties. Our study suggests that coupling AWD practices targeting a soil VWC of less than or equal to 30% coupled with the use of cultivars developed to possess multiple QTLs that negatively regulate grain iAs concentrations will be helpful in mitigating exposure of iAs from rice consumption.

Effects of water management on inorganic arsenic concentration in rice grains in V-furrow direct seeding cultivation

Effects of water management on inorganic arsenic concentration in rice grains in V-furrow direct seeding cultivation

Effects of heavy metals on the expression of digestive enzyme-coding genes in the brackish water flea Diaphanosoma celebensis

Energy metabolism is an essential physiological event for all life forms, and, in heterotrophic organisms, it significantly depends on food intake. Digestive enzymes play an important role in acquiring the nutrients required for metabolic pathways. Thus, the aim of this study was to investigate the transcriptional modulation of digestive enzyme-coding genes in response to heavy metals in the brackish water flea Diaphanosoma celebensis. Sublethal concentrations of inorganic arsenic (As), cadmium (Cd), and lead (Pb) on the brackish water flea D. celebensis were calculated from the 48 h acute toxicity test result. The relative mRNA expression levels of six digestive enzyme-coding genes (AMY and AMY-like for carbohydrates; TRYP and CHY for proteins; LIP and PLRP for lipids) after 48 h of exposure to heavy metals were evaluated by real-time reverse transcription-polymerase chain reaction. A significant increase in the mRNA expression of AMY, AMY-like, TRYP, and PLRP was observed in all concentration of As (1.17–3.94 fold-change, p Pb > As. The increase in digestive enzyme-coding genes in response to As and a lower concentration of Pb may be closely associated with protective effects to compensate for changing food availability. Cd and the higher concentration of Pb could disrupt energy metabolism by downregulating the digestive enzyme-coding genes.

Arsenic speciation and elemental composition of rice samples from the Slovenian market

A survey of highly toxic arsenic compounds, together with some other elements was carried out on 40 polished rice samples (white, basmati and parboiled) and 10 brown rice samples from the Slovenian market. The average total As concentration was 157 ± 60 μg kg−1; highest levels were found in parboiled and brown rice and lowest in basmati. The average inorganic As concentration was 90 ± 35 μg kg−1. Dimethylarsinic acid and monomethylarsonic acid, which also exhibit high toxicity levels in some cases constitute >50% of total arsenic and might deserve more attention. Contrary to other foods, the total arsenic concentration in rice may even be a better health hazard indicator than the inorganic arsenic concentration. Elemental analysis of rice revealed large differences between polished and brown rice, especially for Mg, Mn, P, Fe and K, which were 2–4 times higher in brown rice than in polished rice.

Determination of Inorganic Arsenic in Fish Oil and Fish Oil Capsules by LC-ICP-MS.

As inorganic arsenic is a highly toxic compound, its concentration in foods should be determined. Develop an analytical method for determining inorganic arsenic in fish oil and fish oil capsules. Inorganic arsenic was extracted from fish oil by heating at 80°C in 1.6% tetramethylammonium hydroxide-ethanol. The concentration of inorganic arsenic in fish oil was determined by liquid chromatography (LC) inductively coupled plasma (ICP) MS using an octadecylsilane (ODS) column with a mobile phase containing an ion-pair reagent. The LOD (0.005, 0.004 mg/kg), LOQ (0.016, 0.011 mg/kg), repeatability (4.2, 3.5%), intermediate precision (5.4, 3.5%), and trueness (recoveries 94-109% based on spiked samples) of the proposed method were satisfactory for inorganic arsenic in fish oil and fish oil capsules. A low level of inorganic arsenic was detected only in anchovy oil among all fish oil samples that were used in this study. Inorganic arsenic levels were below the quantitation limit in all fish oil capsules. Inorganic arsenic was determined after extraction from fish oil by heating at 80°C in 1.6% tetramethylammonium hydroxide-ethanol. The level of inorganic arsenic in all fish oil samples examined in this study was lower than 0.1 mg/kg of the maximum level defined in the Codex. Arsenic speciation in fish oil and fish oil capsules was analyzed by LC-ICP-MS using an ODS column with a mobile phase containing an ion-pair reagent. A low level of inorganic arsenic was detected only in anchovy oil. No inorganic arsenic was detected in fish oil capsules.

Seasonal variations in arsenic mobility and bacterial diversity: The case study of Huangshui Creek, Shimen Realgar Mine, Hunan Province, China

Rivers throughout the world have been contaminated by arsenic dispersed from mining activities. The biogeochemical cycling of this arsenic has been shown to be due to factors such as pH, Eh, ionic strength and microbial activity, but few studies have examined the effects of both seasonal changes and microbial community structure on arsenic speciation and flux in mining-affected river systems. To address this research gap, a study was carried out in Huangshui Creek, Hunan province, China, which has been severely impacted by long-term historic realgar (α-As4S4) mining. Water and sediment sampling, and batch experiments at different temperatures using creek sediment, were used to determine the form, source and mobility of arsenic. Pentavalent (AsO43) and trivalent arsenic (AsO33−) were the dominant aqueous species (70–89% and 30–11%, respectively) in the creek, and the maximum concentration of inorganic arsenic in surface water was 10,400 μg/L. Dry season aqueous arsenic concentrations were lower than those in the wet season samples. The sediments contained both arsenate and arsenite, and relative proportions of these varied with season. 8.3 tons arsenic per annum were estimated to be exported from Huangshui Creek. Arsenic release from sediment increased by 3 to 5 times in high water temperature batch experiments (25 and 37 °C) compared to those carried out at low temperature (8 °C). Our data suggest that the arsenic-containing sediments were the main source of arsenic contamination in Huangshui Creek. Microbial community structured varied at the different sample sites along the creek. Redundancy analysis (RDA) showed that both temperature and arsenic concentrations were the main controlling factors on the structure of the microbial community. Protecbacteria, Bacteroidetes, Cyanobacteria, Firmicutes, Verrucomicrobia, and Planctomycetes were the stable dominant phyla in both dry and wet seasons. The genera Flavobacterium, Hydrogenophaga and Sphingomonas occurred in the most highly arsenic contaminated sites, which removed arsenic by related metabolism.Our findings indicate that seasonal variations profoundly control arsenic flux and species, microbial community structure and ultimately, the biogeochemical fate of arsenic.

Inorganic arsenic-mediated upregulation of AS3MT promotes proliferation of nonsmall cell lung cancer cells by regulating cell cycle genes.

Long-term arsenic exposure can promote cancer through epigenetic mechanisms, and arsenite methyltransferase (AS3MT) plays an important role in this process. However, the expression patterns and mechanisms of AS3MT in arsenic carcinogenesis remain unclear. In this study, we found that the AS3MT was overexpressed in arsenic exposed population, non-small cell lung cancer (NSCLC) tissues, and A549 cells with sodium arsenite (NaAsO2 ) treatment for 48 hours. Besides, the level of AS3MT expression was positively correlated with the concentrations of urinary total arsenic (tAs), inorganic arsenic (iAs), methanearsonic acid (MMA), and dimethylarsinic acid (DMA) in all subjects. Functional experiments demonstrated that siRNA-mediated knockdown of AS3MT significantly inhibited proliferation of A549 cells. Mechanism investigation revealed that silencing of AS3MT inhibited proliferation by increasing mRNA expression levels of p21 and E2F1, and inhibiting CDK1, CDK2, CDK4, CDK6, Cyclin A2, Cyclin E1, Cyclin E2, and PCNA mRNA expression. Therefore, arsenic increased AS3MT expression in vivo and in vitro, which could directly act on the cell and affect the progression of NSCLC by regulating cell cycle genes.

Assessing inorganic arsenic in rice and its health risk to consumers in Ho Chi Minh City, Vietnam

PurposeThe consumption of rice that contains high levels of inorganic arsenic may cause human health risk. This study aims to determine As species concentrations, particularly iAs, in raw rice in Ho Chi Minh (HCM) City and its health risks.Design/methodology/approachA total of 60 polished raw composite samples of rice were purchased from traditional markets and supermarkets in HCM City. All samples were analyzed by HPLC-ICPMS for As species determination.FindingsMean concentrations of inorganic arsenic in all samples, which were purchased from supermarket and traditional market, were 88.8 µg/kg and 80.6 µg/kg, respectively. Overall, inorganic arsenic level was 84.7 µg/kg and contributed the highest proportion of arsenic species in rice with 67.7%. The proportion profiles for arsenic species were: As (III) (60 %); dimethylarsinic acid (32.2 %); As (V) (7.7 %) and methylarsonic acid (0.1 %). Inorganic arsenic level in raw rice was below the recommendation of World Health Organization. Using the benchmark dose recommended by the Joint FAO/WHO Expert Committee on Food Additives (JECFA), all exposure doses were lower than BMDL05. However, as the doses ranged from 3.0 to 8.6 of Margin of Exposure (MOE), the health risk of iAs from rice consumption remains public health concern.Originality/valueThe study results report on the surveillance data of the presence of inorganic arsenic in raw rice products, which are available in the supermarkets and traditional markets, and its health risk to consumers in a metropolitan city in Vietnam.