共查询到20条相似文献,搜索用时 31 毫秒
1.
Pascal Salaün Kristopher B. Gibbon-Walsh Georgina M.S. Alves Helena M.V.M. Soares Constant M.G. van den Berg 《Analytica chimica acta》2012
The oxidation potentials of As0/AsIII and Sb0/SbIII on the gold electrode are very close to each other due to their similar chemistry. Arsenic concentration in seawater is low (10–20 nM), Sb occurring at ∼0.1 time that of As. Methods are shown here for the electroanalytical speciation of inorganic arsenic and inorganic antimony in seawater using a solid gold microwire electrode. Anodic stripping voltammetry (ASV) and chronopotentiometry (ASC) are used at pH ≤ 2 and pH 8, using a vibrating gold microwire electrode. Under vibrations, the diffusion layer size at a 5 μm diameter wire is 0.7 μm. The detection limits for the AsIII and SbIII are below 0.1 nM using 2 min and 10 min deposition times respectively. AsIII and SbIII can be determined in acidic conditions (after addition of hydrazine) or at neutral pH. In the latter case, oxidation of As0 to AsIII was found to proceed through a transient AsIII species. Adsorption of this species on the gold electrode at potentials where SbIII diffused away is used for selective deposition of AsIII. Addition of EDTA removes the interfering effect of manganese when analysing AsIII. Imposition of a desorption step for SbIII analysis is required. Total inorganic arsenic (iAs = AsV + AsIII) can be determined without interference from Sb nor mono-methyl arsenious acid (MMA) at 1.6 < pH < 2 using Edep = −1 V. Total inorganic antimony (iSb = SbV + SbIII) is determined at pH 1 using Edep = −1.8 V without interference by As. 相似文献
2.
Multielemental speciation of As, Se, Sb and Te by HPLC-ICP-MS 总被引:2,自引:0,他引:2
An anion exchange HPLC-ICP-MS procedure allowing the simultaneous multielemental speciation analysis of arsenic, selenium, antimony and tellurium has been developed. Four arsenic species (AsIII, AsV, monomethylarsonic acid and dimethylarsinic acid), two selenium species (SeIV and SeVI) may be determined in a single run as well as one antimony (SbV) and one tellurium species (TeVI). Alternatively Sb and/or Te may be used as internal standards for As and Se speciation studies. Optimisation of ICP-MS conditions led to satisfactory relative (0.01 (SbV) to 1.8 (SeVI) ng ml−1) and absolute detection limits (1–180 pg). Reproducibility ranged from 3.1 to 5.6% and the linearity was verified in the 0–200 ng ml−1 range. 相似文献
3.
Chicken is the most consumed meat in North America. Concentrations of arsenic in chicken range from μg kg−1 to mg kg−1. However, little is known about the speciation of arsenic in chicken meat. The objective of this research was to develop a method enabling determination of arsenic species in chicken breast muscle. We report here enzyme-enhanced extraction of arsenic species from chicken meat, separation using anion exchange chromatography (HPLC), and simultaneous detection with both inductively coupled plasma mass spectrometry (ICPMS) and electrospray ionization tandem mass spectrometry (ESIMS). We compared the extraction of arsenic species using several proteolytic enzymes: bromelain, papain, pepsin, proteinase K, and trypsin. With the use of papain-assisted extraction, 10 arsenic species were extracted and detected, as compared to 8 detectable arsenic species in the water/methanol extract. The overall extraction efficiency was also improved using a combination of ultrasonication and papain digestion, as compared to the conventional water/methanol extraction. Detection limits were in the range of 1.0–1.8 μg arsenic per kg chicken breast meat (dry weight) for seven arsenic species: arsenobetaine (AsB), inorganic arsenite (AsIII), dimethylarsinic acid (DMA), monomethylarsonic acid (MMA), inorganic arsenate (AsV), 3-nitro-4-hydroxyphenylarsonic acid (Roxarsone), and N-acetyl-4-hydroxy-m-arsanilic acid (NAHAA). Analysis of breast meat samples from six chickens receiving feed containing Roxarsone showed the presence of (mean ± standard deviation μg kg−1) AsB (107 ± 4), AsIII (113 ± 7), AsV (7 ± 2), MMA (51 ± 5), DMA (64 ± 6), Roxarsone (18 ± 1), and four unidentified arsenic species (approximate concentration 1–10 μg kg−1). 相似文献
4.
Speciation of arsenic in ground water samples: A comparative study of CE-UV, HG-AAS and LC-ICP-MS 总被引:1,自引:0,他引:1
The performance of capillary electrophoresis-ultraviolet detector (CE-UV), hydride generation-atomic absorption spectrometry (HG-AAS) and liquid chromatography-inductively coupled plasma mass spectrometry (LC-ICP-MS) have been compared for the speciation of arsenic (As) in groundwater samples. Two inorganic As species, arsenite (AsIII), arsenate (AsV) and one organo species dimethyl arsenic acid (DMA) were mainly considered for this study as these are known to be predominant in water. Under optimal analytical conditions, limits of detection (LD) ranging from 0.10 (AsIII, AsT) to 0.19 (DMA) μg/l for HG-AAS, 100 (AsIII, DMA) to 500 (AsV) μg/l for CE-UV and 0.1 (DMA, MMA) to 0.2 (AsIII, AsV) μg/l for LC-ICP-MS, allowed the determination of the above three species present in these samples. Results obtained by all the three methods are well correlated (r2 = 0.996*** for total As) with the precision of <5% R.S.D. except CE-UV. The effect of interfering ions (e.g. Fe2+, Fe3+, SO42− and Cl−) commonly found in ground water on separation and estimation of As species were studied and corrected for. Spike recovery was tested and found to be 80-110% at 0.5 μg/l As standard except CE-UV where only 50% of the analyte was recovered. Comparison of these results shows that LC-ICP-MS is the best choice for routine analysis of As species in ground water samples. 相似文献
5.
A novel absorbent was prepared by dimercaptosuccinic acid chemically modifying mesoporous titanium dioxide and was employed as the micro-column packing material for simultaneous separation/preconcentration of inorganic arsenic and antimony species. It was found that both trivalent and pentavalent of inorganic As and Sb species could be adsorbed quantitatively on dimercaptosuccinic acid modified TiO2 within a pH range of 4–7, and only As(III) and Sb(III) could be quantitatively retained on the micro-column within a pH range of 10–11 while As(V) and Sb(V) were passed through the micro-column without the retention. Based on this fact, a new method of flow injection on-line micro-column separation/preconcentration coupled to inductively coupled plasma optical emission spectrometry was developed for simultaneous speciation of trace inorganic arsenic and antimony in natural waters. Under the optimized conditions, an enrichment factor of 10 and sampling frequency of 10 h− 1 were obtained with on-line mode. The detection limits of As(III), As(V), Sb(III), and Sb(V) are 0.53, 0.49, 0.77 and 0.71 ng mL− 1 for on-line mode and as low as 0.11, 0.10, 0.15 and 0.13 ng mL− 1 for off-line mode due to its higher enrichment factor (50), respectively. The relative standard deviations of two modes are less than 6.7% (C = 20 ng mL− 1, n = 7). The concentration ratio of lower oxidation states/higher oxidation states changing from 1:10 to 10:1 has no obvious effect on the recoveries of As(III) and Sb(III). In order to validate the developed method, two certified reference materials of GSBZ5004-88 and GBW(E)080545 water sample were analyzed and the determined values are in good agreement with the certified values. The proposed method was successfully applied to the simultaneous speciation of inorganic arsenic and antimony in natural waters. 相似文献
6.
Arsenic Speciation in Urine and Blood Reference Materials 总被引:1,自引:0,他引:1
Todor I. Todorov John W. Ejnik Florabel G. Mullick Jose A. Centeno 《Mikrochimica acta》2005,151(3-4):263-268
Acute and chronic exposure to arsenic is a growing problem in the industrialized world. Arsenic is a potent carcinogen and
toxin in humans. In the body, arsenic is metabolized to produce several species, including inorganic forms, such as trivalent
(AsIII) and pentavalent (AsV), and the methylated metabolites such as monomethylarsonic acid, (MMAV), and dimethylarsinic acid (DMAV), in addition to arsenobetaine (AsB) which is ingested and excreted from the body in the same form. Each of these species
has been reported to possess a specific but different degree of toxicity. Thus, not only is the measurement of total As required,
but also quantification of the individual metabolites is necessary to evaluate the toxicity and risk assessment of this element.
There are a large number of reference materials that are used to validate methodology for the analysis of As in blood and
urine, but they are limited to total As concentrations. In this study, the speciation of five arsenic metabolites is reported
in blood and urine from commercial available control materials certified for total arsenic levels. The separation was performed
with an anion exchange column using inductively coupled plasma mass spectrometry as a detector. Baseline separation was achieved
for AsIII, AsV, MMAV, DMAV, and AsB, allowing us to quantify all five species. Excellent agreement between the total arsenic levels and the sum of the
speciated As levels was obtained. 相似文献
7.
W. D. James T. Raghvan T. J. Gentry G. Shan R. H. Loeppert 《Journal of Radioanalytical and Nuclear Chemistry》2008,278(2):267-270
Sensitivities for the measurement of four arsenic species, AsIII, AsV, monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA), in environmental waters and rice extracts by a new neutron
activation analysis (NAA) method using pre-separation of the species by liquid chromatography were determined. A manual fraction
collection was used to isolate the species, followed by instrumental neutron activation analysis procedures. The sensitivities
determined for arsenic species in the samples varied from 1.21 to 1.47 ng per vial or about 30 μg·L−1 in sample solutions which translates to about 900 ng arsenic per gram of rice for our HPLC-NAA experiments. 相似文献
8.
A method was developed for the simultaneous speciation of arsenic and antimony with HPLC-ICP-MS using C30 reversed phase column. Eight kinds of arsenic compounds (As(III), As(V), monomethylarsonic acid (MMAA), dimethylarsinic acid (DMAA), arsenobetaine (AB), arsenocholine (AsC), trimethylarsine oxide (TMAO) and tetramethylarsonium (TeMA)), Sb(III) and Sb(V) were simultaneously separated by the special mobile phase containing ammonium tartrate. Especially for the species of organic As, a C30 column was better than a C18 column in the effect of separation. Limits of detection (LOD) for these elements were 0.2 ng ml−1 for the species of each As, and 0.5 ng ml−1 for the species of each Sb, when a 10 μl of sample was injected, respectively. The proposed method was applied to a hot spring water and a fish sample. 相似文献
9.
Shivani Sharma Aamod V. Desai Biplab Joarder Sujit K. Ghosh 《Angewandte Chemie (International ed. in English)》2020,59(20):7788-7792
Selectively capturing toxic oxoanions of selenium and arsenic is highly desired for the remediation of hazardous waste. Ionic metal–organic frameworks (iMOFs) especially cationic MOFs (iMOF‐C) as ion‐exchange materials, featuring aqueous phase stability, present a robust pathway for sequestration of the oxoanions owing to their ability to prevent leaching because of their ionic nature. On account of scarcity of water‐stable cationic MOFs, the capture of oxoanions of selenium and arsenic has been a major challenge and has not been investigated using iMOFs. Herein, we demonstrate large scale synthesis of cationic MOF, viz. iMOF‐1C that exhibits selective capture of oxoanions of SeVI (SeO42?) and AsV (HAsO42?) in water with a maximum sorption capacity of 100 and 85 mg g?1, respectively. This represents among the highest uptake capacities observed for selenate oxoanion in MOFs. Further, the ion‐exchange mechanism was directly unveiled by single crystal analysis, which revealed variable modes of host–guest binding. 相似文献
10.
Shivani Sharma Dr. Aamod V. Desai Dr. Biplab Joarder Dr. Sujit K. Ghosh 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(20):7862-7866
Selectively capturing toxic oxoanions of selenium and arsenic is highly desired for the remediation of hazardous waste. Ionic metal–organic frameworks (iMOFs) especially cationic MOFs (iMOF-C) as ion-exchange materials, featuring aqueous phase stability, present a robust pathway for sequestration of the oxoanions owing to their ability to prevent leaching because of their ionic nature. On account of scarcity of water-stable cationic MOFs, the capture of oxoanions of selenium and arsenic has been a major challenge and has not been investigated using iMOFs. Herein, we demonstrate large scale synthesis of cationic MOF, viz. iMOF-1C that exhibits selective capture of oxoanions of SeVI (SeO42−) and AsV (HAsO42−) in water with a maximum sorption capacity of 100 and 85 mg g−1, respectively. This represents among the highest uptake capacities observed for selenate oxoanion in MOFs. Further, the ion-exchange mechanism was directly unveiled by single crystal analysis, which revealed variable modes of host–guest binding. 相似文献
11.
An online UV photolysis and UV/TiO2 photocatalysis reduction device (UV–UV/TiO2 PCRD) and an electrochemical vapor generation (ECVG) cell have been used for the first time as an interface between high-performance liquid chromatography (HPLC) and atomic fluorescence spectrometry (AFS) for selenium speciation. The newly designed ECVG cell of approximately 115 L dead volume consists of a carbon fiber cathode and a platinum loop anode; the atomic hydrogen generated on the cathode was used to reduce selenium to vapor species for AFS determination. The noise was greatly reduced compared with that obtained by use of the UV–UV/TiO2 PCRD–KBH4–acid interface. The detection limits obtained for seleno-DL-cystine (SeCys), selenite (SeIV), seleno-DL-methionine (SeMet), and selenate (SeVI) were 2.1, 2.9, 4.3, and 3.5 ng mL–1, respectively. The proposed method was successfully applied to the speciation of selenium in water-soluble extracts of garlic shoots cultured with different selenium species. The results obtained suggested that UV–UV/TiO2 PCRD–ECVG should be an effective interface between HPLC and AFS for the speciation of elements amenable to vapor generation, and is superior to methods involving KBH4. 相似文献
12.
Comparative study of atomic fluorescence spectroscopy and inductively coupled plasma mass spectrometry for mercury and arsenic multispeciation 总被引:1,自引:0,他引:1
Gómez-Ariza JL Lorenzo F García-Barrera T 《Analytical and bioanalytical chemistry》2005,382(2):485-492
Mercury and arsenic are two elements of undoubted importance owing to their toxic character. Although speciation of these elements has been developed separately, in this work for the first time the speciation of As and Hg using two atomic fluorescence detectors in a sequential ensemble is presented. A coupling based on the combination of high-performance liquid chromatography (where mercury and arsenic species are separated) and two atomic fluorescence detectors in series, with several online treatments, including photooxidation (UV) and hydride generation, has allowed the determination of mercury and arsenic compounds simultaneously. The detection limits for this device were 16, 3, 17, 12 and 8 ng mL–1 for AsIII, monomethylarsinic acid, AsV, Hg2+ and methylmercury, respectively. This coupling was compared with an analogous one based on inductively coupled plasma–mass spectrometry (ICP-MS) detection, with detection limits of 0.7, 0.5, 0.8, 0.9 and 1.1 ng mL–1, respectively. Multispeciation based on ICP-MS exhibits better sensitivity than the coupling based on tandem atomic fluorescence, but this second device is a very robust system and exhibits obvious advantages related to the low cost of acquisition and maintenance, as well as easy handling, which makes it a suitable system for routine laboratories. 相似文献
13.
Batch sorption of arsenic, antimony and bismuth from solutions in 1 M sulphuric acid has distribution coefficients of 104–105. Quantitative sorption on the hydrophilic methacrylate gel containing thiol groups (Spheron Thiol) is possible within 60 min for bismuth or arsenic and 120 min for antimony. Conditions for the electrothermal atomization of arsenic sorbed on Spheron Thiol and injected into the graphite tube as a suspension are optimized. The sensitivities possible are 3.2 ng As ml-1, 13 ng Sb ml-1 and 2.8 ng Bi ml-1; the coefficient of variation for 10 ng of As is 4%. Complete recovery of 40 ng As ml-1 added to solutions of 5% KCI or 5% MgCl2 and to river water was obtained. 相似文献
14.
Twelve commercially available edible marine algae from France, Japan and Spain and the certified reference material (CRM) NIES No. 9 Sargassum fulvellum were analyzed for total arsenic and arsenic species. Total arsenic concentrations were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) after microwave digestion and ranged from 23 to 126 μg g−1. Arsenic species in alga samples were extracted with deionized water by microwave-assisted extraction and showed extraction efficiencies from 49 to 98%, in terms of total arsenic. The presence of eleven arsenic species was studied by high performance liquid chromatography–ultraviolet photo-oxidation–hydride generation atomic–fluorescence spectrometry (HPLC–(UV)–HG–AFS) developed methods, using both anion and cation exchange chromatography. Glycerol and phosphate sugars were found in all alga samples analyzed, at concentrations between 0.11 and 22 μg g−1, whereas sulfonate and sulfate sugars were only detected in three of them (0.6-7.2 μg g−1). Regarding arsenic toxic species, low concentration levels of dimethylarsinic acid (DMA) (<0.9 μg g−1) and generally high arsenate (As(V)) concentrations (up to 77 μg g−1) were found in most of the algae studied. The results obtained are of interest to highlight the need to perform speciation analysis and to introduce appropriate legislation to limit toxic arsenic species content in these food products. 相似文献
15.
A study was conducted to develop a microwave-enhanced extraction method for the determination of arsenic species in prenatal and children's dietary supplements prepared from plant materials. The method was optimized by evaluating the efficiency of various solutions previously used to extract arsenic from the types of plant materials used in the dietary supplement formulations. A multivitamin standard reference material (NIST SRM 3280) and a prenatal supplement sample were analyzed in the method optimization. The identified optimum conditions were 0.25 g of sample, 5 mL of 0.3 mol L−1 orthophosphoric acid (H3PO4) and microwave heating at 90 °C for 30 min. The extracted arsenic was speciated by cation exchange ion chromatography–inductively coupled plasma mass spectrometry (IC–ICP-MS). The method detection limit (MDL) for the arsenic species was in the range 2–8 ng g−1. Ten widely consumed prenatal and children's dietary supplements were analyzed using the optimized protocol. The supplements were found to have total arsenic in the concentration range 59–531 ng g−1. The extraction procedure recovered 61–92% of the arsenic from the supplements. All the supplementary products were found to contain arsenite (As3+) and dimethylarsinic acid (DMA). Arsenate (As5+) was found in two of the supplements, and an unknown specie of arsenic was detected in one product. The results of the analysis were validated using mass balance by comparing the sum of the extracted and non-extracted arsenic with the total concentration of the element in the corresponding samples. 相似文献
16.
Arsenic pollution of public water supplies has been reported in various regions of the world. Recently, some cancer patients are treated with arsenite (AsIII); most Japanese people consume seafoods containing large amounts of negligibly toxic arsenic compounds. Some of these arsenic species are metabolized, but some remain intact. For the determination of toxic AsIII, a simple, rapid and sensitive method has been developed using electrospray ionization mass spectrometry (ESI-MS). AsIII was reacted with a chelating agent, pyrrolidinedithiocarbamate (PDC, C4H8NCSS-) and tripyrrolidinedithiocarbamate-arsine, As(PDC)3, extracted with methyl isobutyl ketone (MIBK). A 1 μL aliquot of MIBK layer was directly injected into ESI-MS instrument without chromatographic separation, and was detected within 1 min. Arsenate (AsV) was reduced to AsIII with thiosulfate, and then the total inorganic As was quantified as AsIII. This method was validated for the analysis of urine samples. The limit of detection of As was 0.22 μg L−1 using 10 μL of sample solution, and it is far below the permissible limit of As in drinking water, 10 μg L−1, recommended by the WHO. Results were obtained in < 10 min with a linear calibration range of 1-100 μg L−1. Several organic arsenic compounds in urine did not interfere with AsIII detection, and the inorganic As in the reference materials SRM 2670a and 1643e were quantified after the reduction of AsV to AsIII. 相似文献
17.
The toxicity of certain elements is known to be related to their organic substituents and/or oxidation states. As such, total elemental determinations do not always yield sufficient information for accurate risk assessments and therefore speciation or fractionation data are required. In order to obtain fractionation data for trace levels of arsenic and selenium, a novel sequential pneumatic nebulisation (PN)/hydride generation (HG) inductively coupled plasma mass spectrometry (ICP-MS) method was developed. The method offers the advantage of sample introduction via either PN or HG by simply rotating a 4-way switching valve while the system is in operation. In PN mode, the liquid sample is aspirated into ICP, allowing for the determination of the total amount of each element, whilst in HG mode only the arsenic and selenium species that form volatile hydrides are determined. Conveniently, in the case of arsenic, this allows for differentiation between the four most toxic arsenic species (arsenate, arsenite, monomethylarsonic acid and dimethylarsinic acid), which form volatile hydrides, and the virtually non-toxic forms (arsenobetaine, arsenosugars, etc.), which do not. This allows for the rapid estimation of the amounts of toxic and non-toxic arsenic species present in a sample. For arsenic, the technique gave detection limits of 36 ng l−1 in PN mode and 1 ng l−1 in HG mode. For selenium, detection limits of 150 ng l−1 were achieved in PN mode and 220 ng l−1 in HG mode. The technique also gave good long- and short-term stabilities of under 6% RSD for both elements. A variety of samples, including water and urine standard reference materials, were analysed in both modes, and the precision and accuracy of the results for total arsenic and selenium levels were assessed. Using the technique in both modes also allowed for the fractionation of As and Se species into their volatile hydride-forming and non-hydride-forming species. This was particularly informative, with respect to As species present, in the case of a kelp powder extract. Digested tobacco samples were only analysed for their total As levels, in which case results obtained via both sample introduction modes showed good agreement. 相似文献
18.
Hui-Ming LiuShi-Yang Chen Pin-Hsuan ChangSuh-Jen Jane Tsai 《Analytica chimica acta》2002,459(1):161-168
Diverse matrix effects on the determination of bismuth, selenium and tellurium (μg g−1) in nickel-based alloys and pure copper by flow-injection hydride generation atomic absorption spectrometry (FIAS-HGAAS) were investigated. Sodium tetrahydroborate was used as the reductant. The separation of analytes from copper matrix was mandatory while the analytes were successfully determined without being separated from the alloy matrix. Hydrochloric acid was effective in the prereduction of bismuth and selenium, however, it did not give any satisfactory result for tellurium in nickel-based alloys. In this work, 5% (w/v) ascorbic acid was proved effective for the prereduction of tellurium.Successful determination of tellurium in copper was achieved when N-nitroso-N-phenylhydroxylamine (cupferron) chelation-extraction was employed for the separation of tellurium from copper matrix. Cupferron chelation-extraction was performed in phosphate buffer (a mixture of 0.2 mol l−1 sodium phosphate and 0.1 mol l−1 citric acid). Lanthanum hydroxide coprecipitation at pH 10.0±0.5 was effective for bismuth and selenium. Standard reference materials of nickel-based alloys and pure copper were analyzed using the proposed methods. The linear range for the calibration curves were 0.30-15 and 0.20-10 ng ml−1 for BiH3 and H2Se, respectively, with a correlation coefficient of 0.9995. For H2Te, the linear range for the calibration curves was 0.50-12 ng ml−1 with the correlation coefficient of 0.9994. Good agreement was obtained between experimental values and certified values. Satisfactory recovery ranged from 91±1 to 106±2% was obtained from five replicate determinations. 相似文献
19.
Dapeng Wang Yasuyo Shimoda Hidetoshi Kurosawa Jian Liu Xiguo Xu Xing Liu 《International journal of environmental analytical chemistry》2015,95(5):379-389
There are no reports in scientific literature on arsenic species in human saliva after seaweed exposure. The present article reports for the first time the regular excretion patterns of arsenic in the saliva of volunteers with one-time ingestion of Chinese seaweed. Total arsenic and speciation analyses were carried out by high-performance liquid chromatography–inductively coupled plasma–mass spectrometry (HPLC-ICP-MS). Results show that the excretion time of total arsenic in saliva is a trifle earlier than that in urine, total arsenic in human saliva also shows a regular excretion pattern like that in urine within 72 h after exposure to seaweed. For speciation analysis, four species, including the major dimethylarsinic acid (DMA) species, were detected in urine prior to seaweed intake. Six species were detected in urine after seaweed ingestion, including DMA, methylarsonic acid (MMA), oxo-dimethylarsinoylethanol (oxo-DMAE), thio-dimethlyarsenoacetate (thio-DMAA), arsenite (AsIII) and arsenate (AsV). In saliva samples, three species were found before seaweed ingestion, with the major peak identified as AsIII. After consumption, the kinds of arsenic metabolites in saliva were less than those in urine. The major species was inorganic arsenic (iAs AsIII+AsV), followed by DMA, MMA and a trace amount of oxo-DMAE. Taken together, the present study suggests that saliva assay can be used as a potential tool for understanding the regular excretion pattern of total arsenic after seaweed ingestion. Whether or not it’s an efficient tool for assessing arsenic metabolites in humans exposed to seaweed requires further investigation. 相似文献
20.
Known analytical techniques are not applicable to the accurate and precise determination of AsV and total arsenic (Ast) in the mixtures of AsIII and AsF6−. For this reason, an accurate and precise analytical procedure for determination of the content of AsV and Ast in the range of 5-10 mg of As with a relative standard deviation (R.S.D.) smaller than 0.4% was developed. The results were proved by the determination of AsIII by titration with KBrO3 and gravimetric determination of AsF6− species. 相似文献