Evaluation of stability of arsenic species in rice

Pizarro, Isabel; Gómez, Milagros; Palacios, María A.; Cámara, Carmen

doi:10.1007/s00216-003-1870-9

Cited by 69 publications

(39 citation statements)

References 17 publications

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“…In all comparisons, rice from the U.S. and the EU contained significantly higher levels (p < 0.05) of As than rice from Asia ( Figure 2). However, mean As concentrations for rice from the EU and U.S. in the present study were significantly lower than those determined from previous studies (0.152 versus 0.213 mg kg -1 for the EU; 0.19 versus 0.255 mg kg -1 for the U.S.) (9,(11)(12)(13). The mean As concentration in the large data set from Bangladesh (10) was significantly higher by a factor of 1.5-2 times compared to the other data sets for Asian rice.…”

Section: Methodscontrasting

confidence: 88%

Arsenic in Rice: I. Estimating Normal Levels of Total Arsenic in Rice Grain

Zavala¹,

Duxbury²

2008

Environ. Sci. Technol.

285

132

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High levels of arsenic (As) in rice grain are a potential concern for human health. Variability in total As in rice was evaluated using 204 commercial rice samples purchased mostly in retail stores in upstate New York and supplemented with samples from Canada, France, Venezuela, and other countries. Total As concentration in rice varied from 0.005 to 0.710 mg kg -1 . We combined our data set with literature values to derive a global "normal" range of 0.08-0.20 mg kg -1 for As concentration in rice. The mean As concentrations for rice from the U.S. and Europe (both 0.198 mg kg -1 ) were statistically similar and significantly higher than rice from Asia (0.07 mg kg -1 ). Using two large data sets from Bangladesh, we showed that As contaminated irrigation water, but not soil, led to increased grain As concentration. Wide variability found in U.S. rice grain was primarily influenced by region of growth rather than commercial type, with rice grown in Texas and Arkansas having significantly higher mean As concentrations than that from California (0.258 and 0.190 versus 0.133 mg kg -1 ). Rice from one Texas distributor was especially high, with 75% of the samples above the global "normal" range, suggesting production in an As contaminated environment.

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Section: Methodscontrasting

confidence: 88%

Arsenic in Rice: I. Estimating Normal Levels of Total Arsenic in Rice Grain

Zavala¹,

Duxbury²

2008

Environ. Sci. Technol.

285

132

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“…Extractions were conducted in the dark to avoid speciation changes due to UV radiation. Following shaking the extraction vessels were placed for 5 minutes in a sonic bath 24 , centrifuged for 15 minutes at 2000 rpm and the 15 supernatant carefully removed. Only one extraction step was employed as any additional arsenic contained in the second and subsequent extractions has been shown to be accountable to the residual dissolved arsenic carried over from previous extractions.…”

Section: Sample Extraction Soils and Castsmentioning

confidence: 99%

Arsenic biotransformation in earthworms from contaminated soils

et al. 2009

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Two species of arsenic (As) resistant earthworm, Lumbricus rubellus and Dendrodrillus rubidus, their host soils and soil excretions (casts) were collected from 23 locations at a former As mine in 5 Devon, UK. Total As concentrations, measured by ICP-MS, ranged from 255 to 13,080 mg kg -1 in soils, 11 to 877 mg kg -1 in earthworms and 284 to 4221 mg kg -1 in earthworm casts from a subsample of 10 of the 23 investigated sites. The samples were also measured for As speciation using HPLC-ICP-MS to investigate potential As biotransformation pathways. Inorganic arsenate (As V ) and arsenite (As III ) were the only species detected in the soil. As V and As III were also the dominant 10 species found in the earthworms and cast material together with lower proportions of the organic species methylarsonate (MA V ), dimethylarsinate (DMA V ), arsenobetaine (AB) and three arsenosugars. Whilst the inorganic As content of the earthworms increased with increasing As body burden, the concentration of organic species remained relatively constant. These results suggest that the biotransformation of inorganic arsenic to organic species does not contribute to As 15 resistance in the sampled earthworm populations. Quantification of As speciation in the soil, earthworms and cast material allows a more comprehensive pathway for the formation of AB in earthworms to be elucidated. Received (in XXX, IntroductionThe chemistry of As in environmental and biological systems is complex. Whilst inorganic As species are the most prevalent in abiotic environments, the uptake of inorganic As 25 by living organisms can lead to the synthesis of organic As species 1 through biotransformation. The ubiquitous, epegeic earthworm species L. rubellus and D. rubidus are known to inhabit soils highly contaminated with As at the former mine site of Devon Great Consols (DGC), UK. [2][3][4][5] These earthworms 30 are clearly resistant to As toxicity and several potential coping mechanisms have been proposed, yet the underlying mechanism behind this resistance is unknown. Behavioural adaptation, whereby the earthworm avoids contact with the contaminant, 4 is unlikely as earthworms from DGC are known 35 to have elevated As body burdens. 2,4, 5 The biotransformation of highly toxic inorganic As to the less toxic organic species arsenobetaine (AB) has been speculated as a mode of mitigating As toxicity in DGC earthworms. 2,4 An alternative mechanism involves the sequestration of arsenic in the 40 metallothionein-rich chloragogenous tissue which separates the intestine from the coelomic cavity. 3 With this mechanism it is proposed that inorganic As III binds to the sulphur-rich metallothionein thereby sequestering ingested As in a form that is not biologically reactive. The study of As speciation can provide important information on As biotransformation and toxicity and to date a multitude of organic As species have been identified. 7 The occurrence of organic As species and their biotransformation pathways are well documented in marine organisms such as crus...

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“…High arsenic concentrations in irrigated soils and water may lead to evaluated concentrations of arsenic in rice grain or in rice straw (Pizarro et al, 2003). This method was applied to separation and determination of As(III) in rice straw and its ash, drinking water, mineral water and well water samples.…”

Section: Analytical Applicationmentioning

confidence: 99%

Separation and preconcentration of Arsenic(III) ions from aqueous media by adsorption on MWCNTs

Tavakkoli

Habibollahi

Tehrani

2017

Arabian Journal of Chemistry

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A simple and sensitive method using mini-column packed with multi-walled carbon nanotubes (MWCNTs) combined with graphite furnace atomic absorption spectrometry (GFAAS) for preconcentration and determination of ultra trace amounts of As(III) in an aqueous medium is proposed. The procedure is based on the solid phase extraction of the As(III)-sodium diethyldithiocarbamate (As-NaDDTC) chelate on MWCNTs. Various parameters such as the effect of pH, eluent type and volume, amount of sorbent, and matrix effects on the quantitative recoveries of analyte ions were evaluated. It was found that sorption is quantitative and desorption occurs with 4.0 mL of 3.0 mol L À1 HNO 3 in acetone. The limit of detection of the method was 0.008 ng mL À1 for GFAAS with enrichment factor of 125 and the relative standard deviation (RSD) 0.97% (n = 8, C = 10 ng mL À1 ). This method has been applied to the determination of ultra trace As(III) in water and rice plant and its ash successfully.

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Evaluation of stability of arsenic species in rice

Cited by 69 publications

References 17 publications

Arsenic in Rice: I. Estimating Normal Levels of Total Arsenic in Rice Grain

Arsenic in Rice: I. Estimating Normal Levels of Total Arsenic in Rice Grain

Arsenic biotransformation in earthworms from contaminated soils

Separation and preconcentration of Arsenic(III) ions from aqueous media by adsorption on MWCNTs

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