Determination Method for Total Arsenic and Partial-digestion Method with Nitric Acid for Inorganic Arsenic Speciation in Several Varieties of Rice

Abstract The aim of this investigation was to study the distribution of arsenic species in human organs following fatal acute intoxication by arsenic trioxide. The collected autopsy samples of most organs were ground and dried, and the total arsenic was measured by electrothermal atomic absorption spectrometry (ETAAS). The arsenic species—inorganic arsenic, in the form of arsenite [As(III)] and arsenate [As(V)], and its metabolites [monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA)]—were quantified by ETAAS after extraction with methanol/water (1:1, by volume) and separation by HPLC. The results indicate that after acute intoxication, the liver and kidneys show the highest concentrations of total arsenic and that the total concentration in blood is 7- to 350-fold less concentrated than in organs. In all organs, As(III) is the predominant species, and MMA is more concentrated than DMA. MMA and DMA are more prevalent in lipidic organs (49% of total arsenic) compared with other organs (25% of total arsenic). As(V) was found in small quantities in the liver, kidneys, and blood.

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Groundwater Irrigation and Arsenic Speciation in Rice in Cambodia

Journal of Health and Pollution ◽

10.5696/2156-9614-8.19.180911 ◽

2018 ◽

Vol 8 (19) ◽

Cited By ~ 4

Author(s):

Tom Murphy ◽

Kongkea Phan ◽

Emmanuel Yumvihoze ◽

Kim Irvine ◽

Ken Wilson ◽

...

Keyword(s):

Arsenic Speciation ◽

Arsenic Concentration ◽

Arsenic Exposure ◽

Inorganic Arsenic ◽

Arsenic Species ◽

Dimethylarsinic Acid ◽

Total Arsenic ◽

Groundwater Irrigation ◽

Financial Interests ◽

Rice Consumption

Background. Arsenic bioaccumulation in rice is a global concern affecting food security and public health. Objective. The present study examined arsenic species in rice in Cambodia to characterize health risks with rice consumption and to clarify uncertainties with Codex guidelines. Methods. The present study collected 61 well water samples, 105 rice samples, 70 soil samples, and conducted interviews with 44 families in Preak Russey near the Bassac River and Kandal Province along the Mekong River in Cambodia. Analyses of metals, total arsenic and arsenic species were conducted in laboratories in Canada, Cambodia and Singapore. Results. Unlike in Bangladesh, rice with the highest total arsenic concentrations in Cambodia contains mostly organic arsenic, dimethylarsinic acid (DMA), which is unregulated and much less toxic than inorganic arsenic. The present study found that storing surface runoff in ditches prior to irrigation can significantly reduce the arsenic concentration in rice. It is possible to remove > 95% of arsenic from groundwater prior to irrigation with natural reactions. Conclusions. The provision of high quality drinking water in 2015 to Preak Russey removed about 95% of the dietary inorganic arsenic exposure. The extremes in arsenic toxicity that are still obvious in these farmers should become less common. Rice from the site with the highest documented levels of arsenic in soils and water in Cambodia passes current Codex guidelines for arsenic. Informed Consent. Obtained Competing Interests. The authors declare no competing financial interests.

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Arsenic speciation in rice and risk assessment of inorganic arsenic from Ghentugachhi village of Chakdaha block, Nadia, West Bengal, India

ORYZA- An International Journal on Rice ◽

10.35709/ory.2020.57.2.1 ◽

2020 ◽

Vol 57 (2) ◽

pp. 85-93

Author(s):

B Sinha ◽

K Bhattacharyya

Keyword(s):

Mass Spectrometry ◽

Inductively Coupled Plasma ◽

West Bengal ◽

Arsenic Speciation ◽

Inorganic Arsenic ◽

Rice Grain ◽

Species Determination ◽

Inductively Coupled ◽

As Species ◽

Plasma Mass Spectrometry

The purpose of the present study was to assess arsenic (As) speciation in rice from West Bengal, India, in order to improve understanding of the health risk posed by arsenic in Indian rice. Rice is a potentially important route of human exposure to arsenic, especially in populations with rice-based diets. However, arsenic toxicity varies greatly with species. Determination of arsenic (As) species in rice is necessary because inorganic As species are more toxic than organic As. Total arsenic was determined by inductively coupled plasma mass spectrometry; arsenite, arsenate, monomethylarsonic acid, and dimethyarsinic acid were quantified by high-performance liquid chromatography- inductively coupled plasma mass spectrometry. The analysis of a rice flour certified reference material (SRM-1568-a) were evaluated for quality assurance. The use of 2M TFA for extraction with an isocratic mobile phase was optimized for extraction and employed for arsenic speciation in rice. The extraction method showed a high recovery of arsenic. Most of the As species in rice were noticed to be inorganic [Arsenite (As-III), Arsenate As-V]. It appeared very clear from the present study that inorganic arsenic shared maximum arsenic load in rice straw while in grains it is considerably low. As species recovered from rice grain and straw are principally As-III and As-V with a little share of DMA and almost non-detectable MMA and As-B. The order of As species in rice grain revealed in this study were As-III (54.5-65.4 %)>As-V(21.2-28.3%)>DMA(5.2%).

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Arsenic Speciation: Reduction of Arsenic(V) to Arsenic(III) by Fulvic Acid

Environmental Chemistry ◽

10.1071/en05095 ◽

2006 ◽

Vol 3 (2) ◽

pp. 137 ◽

Cited By ~ 17

Author(s):

Tsanangurayi Tongesayi ◽

Ronald B. Smart

Keyword(s):

Fulvic Acid ◽

Arsenic Removal ◽

Research Effort ◽

Arsenic Speciation ◽

Inorganic Arsenic ◽

Stripping Voltammetry ◽

Reduction Reaction ◽

Cathodic Stripping Voltammetry ◽

Suwannee River Fulvic Acid ◽

Removal Technologies

Environmental Context.Most technologies for arsenic removal from water are based on the oxidation of the more toxic and more mobile arsenic(iii) to the less toxic and less mobile arsenic(v). As a result, research effort has been focussed on the oxidation of arsenic(iii) to arsenic(v). It is equally important to explore environmental factors that enhance the reduction of arsenic(v) to arsenic(iii). An understanding of the redox cycling of arsenic could result in the development of cheaper and more efficient arsenic removal technologies, especially for impoverished communities severely threatened by arsenic contamination. Abstract.The objective of this study was to investigate the reduction of inorganic arsenic(v) with Suwannee River fulvic acid (FA) in aqueous solutions where pH, [FA], [As(v)], [As(iii)], and [Fe(iii)] were independently varied. Samples of inorganic As(v) were incubated with FA in both light and dark at constant temperature. Sterilisation techniques were employed to ensure abiotic conditions. Aliquots from the incubated samples were taken at various time intervals and analysed for As(iii) using square-wave cathodic-stripping voltammetry at a hanging mercury drop electrode. The study demonstrated the following important aspects of As speciation: (1) FA can significantly reduce As(v) to As(iii); (2) reduction of As(v) to As(iii) is a function of time; (3) both dark and light conditions promote reduction of As(v) to As(iii); (4) Fe(iii) speeds up the reduction reaction; and (5) oxidation of As(iii) to As(v) is promoted at pH 2 more than at pH 6.

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