Hydride Generation Atomic Absorption Spectrophotometry Research Articles

Enhanced digestion of complex cosmetic matrices for analysis of As, Hg, Cd, Cr, Ni, and Pb using triton X-100

A suitable optimized digestion method for lipsticks and powders for the analysis of As, Hg, Cd, Cr, Ni and Pb by Hydride Generation Atomic Absorption Spectrophotometry (HG-AAS), Cold Vapor Atomic Absorption Spectrophotometry (CV-AAS) and Flame Atomic Absorption Spectrophotometry (FAAS) was developed using common acid digestion methods enhanced by the use of Triton X-100. The three acid digestion methods used in this study were Method A (nitric acid and hydrogen peroxide), Method B (nitric acid and hydrochloric acid) and Method C (nitric acid, hydrochloric acid and hydrogen peroxide). Triton X-100 was added to each of these and the effects were studied. The acid digestion method that was determined to be the most suitable and efficient for lipsticks and powders was Method A-1 (nitric acid and hydrogen peroxide with 5% Triton X-100 at 95 °C for 3 h). The range of percentage recoveries obtained were; powders (98.50% to 92. 61%) and lipsticks (100.96% to 99.41%) for As, Cd, Cr, Pb, Hg and Ni. The addition of Triton X-100 significantly improved the efficiency of the method.•Triton X-100 improves the efficiency of acid digestion of fatty hydrophobic samples by dispersing the sample throughout the acid digestant.

Arbuscular mycorrhizal fungi reduce arsenic uptake and improve plant growth in Lens culinaris.

Arsenic (As) is a carcinogenic and hazardous substance that poses a serious risk to human health due to its transport into the food chain. The present research is focused on the As transport in different lentil genotypes and the role of Arbuscular Mycorrhizal Fungi (AMF) in mitigation of As phyto-toxicity. Arsenic transport from soil to root, shoot and grains in different lentil genotypes was analyzed by flow injection hydride generation atomic absorption spectrophotometry. AMF were applied for the reduction of As uptake as well as the improvement of plant growth in lentil genotypes. Arsenic phyto-toxicity was dose-dependent as evidenced by relatively higher shoot length, fresh and dry weight of root and shoot in 5 and 15 mgkg-1 As-treated lentil plants than that in 100 mgkg-1 As-treated lentil. Arsenic accumulation occurred in roots and shoots of all BARI-released lentil genotypes. Arsenic accumulation in grains was found higher in BARI Mashur 1 than other lentil genotypes. AMF treatment significantly increased growth and biomass accumulation in lentil compared to that in non-AMF plants. Furthermore, AMF effectively reduced the As concentrations in roots and shoots of lentil plants grown at 8 and 45 mgkg-1 As-contaminated soils. This study revealed remarkable divergence in As accumulation among different BARI-released lentil genotypes; however, AMF could reduce As uptake and mitigate As-induced phyto-toxicity in lentil. Taken together, our results suggest a great potential of AMF in mitigating As transfer in root and shoot mass and reallocation to grains, which would expand lentil cultivation in As-affected areas throughout the world.

Early Life Arsenic Exposure and Non-Malignant Respiratory Illnesses among Adolescents in Rural Bangladesh

Background/Aim: Evidence suggests that exposure to arsenic through drinking water increases the risk of non-malignant respiratory illnesses including impairment of lung function in adults. However, early life arsenic exposure and subsequent respiratory system effects in adolescents have not been reported so far. Methods: The study was conducted in rural Bangladesh, Matlab. A cohort of 200 children now aged 11-22 years were enrolled of which 107 had in utero and early childhood (first five years) exposure to drinking water arsenic concentration over 400µg/L (exposed group) and 93 had less than 10 µg/L (unexposed group). Histories of respiratory symptoms were collected through a validated structured questionnaire (ISAAC). Lung function (FEV1, FVC) was tested by EasyOne spirometry following the standard American Thoracic Society criteria. Water arsenic concentrations were measured by hydride generation atomic absorption spectrophotometry. Results: The mean age was 15 years. Chronic respiratory symptoms were evident in male participants in the exposed group. In an adjusted model, boys with in early life arsenic exposure (>400 µg/L) were more likely to report wheezing attacks 1-3 times/week (Prevalence Odds Ratio (POR): 4.99, 95% Confidence Interval (CI): 1.00-24.9), wheezing after exercise (POR: 4.14, 95% CI: 1.05-16.4) and waking up with chest tightness (POR: 5.01, 95% CI: 1.00-25.0). Decrease in FEV1 (-117.3 ml, CI: -246.5, 11.8) and FVC (-135.2 ml, CI: -269.9, -0.37) were observed in male respondents in the exposed group compared to the unexposed. No respiratory impairment was observed among exposed girls. Conclusions: High exposure to arsenic in utero and early childhood may result in increased risk of chronic respiratory symptoms and decrements in lung function in adolescent males. We plan to follow this unique cohort further to see if early life arsenic exposure respiratory effects persist in males as they grow older, and remain absent in females.

Chemical characterization and quality assessment of some bottled water brands from the Kohgiluyeh-va-Boyer Ahmad province market, SW Iran

Recently, bottled water consumption has been increased in Iran, because of the priority change from tap water to bottled water usage; therefore, conducting studies on quality control of the bottled drinking waters seems very necessary. In this study, a comparison between the amounts of mineral elements present in 10 bottled water brands from the Kohgiluyeh-va-Boyer Ahmad Province market, SW Iran, and recommended limits by national and international standards and guidelines for drinking water was carried out, with the aim to assess the quality of bottled waters as an outdoor supply source for drinking water. The chosen bottled water brands were analyzed for more than 50 physicochemical parameters, using inductively coupled plasma optical emission spectrometry (ICP-OES), ionic chromatography (IC), hydride generation atomic absorption spectroscopy (HGAAS), spectrophotometry, titration, and conductometry standard methods. The comparison between obtained results and Iranian, United States Environmental Protection Agency (USEPA) and World Health Organization (WHO) standards and guidelines showed that all levels of analyzed parameters do not exceed the permitted limits, indicating that the bottled waters have safe quality for drinking use. Results revealed that bottled waters are a valid substitute of tap water, especially for outdoor drinking purpose. Nevertheless, the mineral elements such as Ca, Mg, Na, and K are not provided by the bottled waters in sufficient levels needed daily by human body.

Arsenic determination in soils and hair from schools in past mining activity areas in Ron Phibun district, Nakhon Si Thammarat province, Thailand and relationship between soil and hair arsenic

Arsenic (As) in soils and hair collected from schools in Ron Phibun district, Nakhon Si Thammarat province, Thailand, where former tin mining operation were located, was determined by hydride generation atomic absorption spectrophotometry. The relationship between As content in soils and hair with distance from secured landfill was also investigated. Soil and hair samples were collected from 6 schools in summer (February) and rainy season (July). For soils, silt+clay (<45 µm) fraction and sand (45 µm–2 mm) fraction were analyzed. The average concentrations of arsenic in soils during summer (21.70 ± 16.79 mg/kg) and rainy season (22.45 ± 14.17 mg/kg) were at the same concentration level. The average arsenic content in hair samples was 2.24 ± 0.05 mg/kg in rainy season which was higher than 1.05 ± 0.04 mg/kg in summer. It was found that arsenic contents in hair and soils are correlated with the distance from the secured landfill. Most importantly, a positive relationship between arsenic content in hair and soil was obtained for rainy season, which indicated that arsenic in soil corresponded to arsenic in hair. The cancer risk from soils ranged from 4.48 × 10−7 to 2.06 × 10−6 indicating low carcinogenic risk to school children.

Study of Arsenic Impurity in Water of Lahore by Hydride Generation-Atomic Absorption Spectrophotometry

Study of Arsenic Impurity in Water of Lahore by Hydride Generation-Atomic Absorption Spectrophotometry

Exiguobacterium mediated arsenic removal and its protective effect against arsenic induced toxicity and oxidative damage in freshwater fish, Channa striata.

Arsenic is a toxic metalloid existing widely in the environment, and its removal from contaminated water has become a global challenge. The use of bacteria in this regard finds a promising solution. In the present study, Exiguobacterium sp. As-9, which is an arsenic resistant bacterium, was selected with respect to its arsenic removal efficiency. Quantification of arsenic in the water treated with bacterium showed that Exiguobacterium efficiently removed up to 99% of arsenic in less than 20h. In order to reveal the possible effect of this bacterium in removal of arsenic from water and protecting fishes from the detrimental effects of arsenic, we initiated a range of studies on fresh water fish, Channa striata. It was observed that the fishes introduced into bacteria treated water displayed no symptoms of arsenic toxicity which was marked by a decreased oxidative damage, whereas the fishes exposed to arsenic revealed a significant (p<0.05) increase in the oxidative stress together with the elevated levels of malondialdehyde. Determination of the bioaccumulation of arsenic in the liver tissues of C. striata using hydride generation atomic absorption spectrophotometry (HG-AAS) revealed an increased As(III) accumulation in the fishes exposed to arsenic whereas the arsenic level in the control and bacteria treated fishes were found below the detectable limit. In conclusion, this study presents the strategies of bacterial arsenic removal with possible directions for future research.

Determination of inorganic arsenic species by hydride generation atomic absorption spectrophotometry and cathodic stripping voltammetry

Determination of inorganic arsenic species by hydride generation atomic absorption spectrophotometry and cathodic stripping voltammetry

Human health risk assessment with spatial analysis: Study of a population chronically exposed to arsenic through drinking water from Argentina

Arsenic (As) is a ubiquitous element widely distributed in the environment. This metalloid has proven carcinogenic action in man.The aim of this work was to assess the health risk related to As exposure through drinking water in an Argentinean population, applying spatial analytical techniques in addition to conventional approaches. The study involved 650 inhabitants from Chaco and Santiago del Estero provinces. Arsenic in drinking water (Asw) and urine (UAs) was measured by hydride generation atomic absorption spectrophotometry. Average daily dose (ADD), hazard quotient (HQ), and carcinogenic risk (CR) were estimated, geo-referenced and integrated with demographical data by a health composite index (HI) applying geographic information system (GIS) analysis. Asw covered a wide range of concentration: from non-detectable (ND) to 2000μg/L. More than 90% of the population was exposed to As, with UAs levels above the intervention level of 100μg/g creatinine.GIS analysis described an expected level of exposure lower than the observed, indicating possible additional source/s of exposure to inorganic arsenic.In 68% of the locations, the population had a HQ greater than 1, and the CR ranged between 5·10−5 and 2,1·10−2. An environmental exposure area through ADD geo-referencing defined a baseline scenario for space-time risk assessment.The time of residence, the demographic density and the potential health considered outcomes helped characterize the health risk in the region. The geospatial analysis contributed to delimitate and analyze the change tendencies of risk in the region, broadening the scopes of the results for a decision-making process.

Effects of Arsenate and Arsenite on Germination and Some Physiological Attributes of Barley Hordeum vulgare L.

Arsenic (As) is toxic to plants and animals. We tested the effects of arsenite and arsenate (0-16 mg/L) on seed germination, and on relative root and shoot length, α-amylase activity, reducing sugars and soluble total protein contents, and malondialdehyde content in barley seedlings. We also measured As accumulation in barley stems and roots. The α-amylase activity, relative root and shoot length, and seed germination decreased with increasing concentrations of arsenate and arsenite. The reducing sugars content in barley seedlings increased after 4 days of growth on media containing As. In general, the protein content in roots and seedlings decreased with increasing doses of As. Arsenic in the tissues was quantified by hydride generation-atomic absorption spectrophotometry. To confirm the accuracy of the method, we analyzed the certified reference material WEPAL-IPE-168. The limit of detection was 1.2 μg/L and the relative standard deviation was <2.0 %.

EFFECTS OF SELENIUM ENRICHMENT OF TOMATO PLANTS ON RIPE FRUIT METABOLISM AND COMPOSITION

EFFECTS OF SELENIUM ENRICHMENT OF TOMATO PLANTS ON RIPE FRUIT METABOLISM AND COMPOSITION

Survey of cadmium, lead, and arsenic in sesame from Iran

Abstract Background Sesame is one of the most consumed oilseeds in human food in the whole world. In various forms, it is used for the preparation of foods, cookies, cakes, and so on. This study was applied for the determination of lead, cadmium, and arsenic in 80 samples of sesame purchased from supermarkets in Khorasan province, Iran. Results The results showed that arsenic is one of the trace elements in crops (edible plants) with an average concentration of 54 ng g−1, and three (3.75%) samples were above the maximum tolerated level of Pb in Iran (100 ng g−1) regulations. Conclusions The results were obtained after complete digestion of these samples and determination using graphite furnace atomic absorption spectrometry and hydride generation atomic absorption spectrophotometry and indicate that 96.25% of the sesame samples could be suitable for human food.

Analysis of Selenium Content in Root and Tuber Plants in Central Nigeria

Some common staple roots and tubers (cassava, yam, sweet potato and yellow yam) were analyzed for selenium content level using hydride generation—atomic absorption spectrophotometry (HG-ASS) technique. Results for duplicate analysis revealed that sweet potato has the highest mean selenium content (19.2 ± 5.20 μg/kg), followed by yellow yam (18.3 ± 6.97 μg/kg), then yam (13.6 ± 7.12 μg/kg) and cassava the least (13.0 ± 5.84 μg/kg). In comparing our results with the literature values, most of the results obtained in this work such as 54.2, 72.3 and 81.8 μg/kg were higher than literature values. The variations could be due to the type of species/variety, geographical location, total selenium concentration in the soil and its bioavailability. In view of the importance of Se to human health and considering the levels found in the staples investigated, we recommend that sweet potato be popularized as a staple, much more than cassava as it is now the case in Central Nigeria.

The influence of diet on intra and inter-individual variability of urinary excretion of arsenic species in Italian healthy individuals

To study the effect of eating foods with a high arsenic (As) content on the intra and inter-individual variability of urinary concentrations of the As species, daily urine samples were collected for 10 consecutive days from 12 healthy male subjects. A daily food diary was kept throughout the study period. Personal exposure to airborne As was measured once during the study. As3, As5, monomethylarsonic acid (MMA), dimethylarsinic acid (DMA) and arsenobetaine were determined in all urine samples by inductive coupled plasma mass spectrometry, and the sum of As3+As5+MMA+DMA (iAs) by hydride generation-atomic absorption spectrophotometry. Exposure to airborne As was below the limit of detection in all samplings. As3 was found in only 19.2% and As5 in only 3.3% of the urine samples, whereas high urinary concentrations of arsenobetaine were observed. With the exception of arsenobetaine, expressed as a percentage, a significant inter-individual variability was observed for all species of As, for iAs and for the MMA/DMA ratio (p<0.001). Instead, the intra-individual variability was significant only for the MMA/DMA ratio (p<0.001). Among foods with a high As content, only a heavy consumption of seafood was shown to influence inter-individual variability of DMA%, arsenobetaine expressed as μgg−1 creatinine and iAs. In conclusion, even in populations with a high intake of organic As through foods, the finding of a significant inter-individual but no significant intra-individual variability of urinary species confirms the usefulness of urinary As speciation for biological monitoring of exposure to As.

Development of a Simple System for the Determination of Arsenic after Hydride Generation Atomic Absorption Spectrophotometry

A simple and inexpensive hydride generation system that uses a pyrex boiling tube as a reduction vessel to hold the acidified sample into which 2cm3 of 100-300mg sodium tetrahydroborate (III) solution isinjected such that the excess molecular hydrogen evolved carries the generated arsine directly through the atomic absorption spectrophotometer nebuliser to a nitrogen-hydrogen entrained air flame for atomic absorption measurement is described. The average absorption by arsenic atoms generated from the total arsine evolved was measured by integrating the absorbance for 16 seconds. The use of the absorption signal integration mode was found to free the technique from most kinetic interferences, while the stripping of the arsine from solution reduces the potential for chemical interferences in the solution phase. Gas flow rates affected sensitivity markedly, but theoptimal flow rates for nitrogen and hydrogen were standardised on 90cm3s-1 and 30cm3s-1 respectively as a compromise between lower flow-rates giving longer arsenic residence times and higher sensitivity, and higher flowrates giving a stiffer, less draught-sensitive flame. An optimum flame height of 6mm above the burner producedsufficient atomization and low background absorption. Generally, sample volumes between 5-20cm3 could be used in different acidic media within the concentration range 10% (v/v) . 50% (v/v). The proposed system produced a significantly improved atomic absorption sensitivity of 25ng and a detection limit of (95% confidence) of 5.2ng forarsenic. Both performance characteristics were found to be better by a factor . 12 and . 27 respectively than achieved with air-acetylene flames. The method is highly reproducible at trace levels having an overall precision of 1% for 0.5ƒÊg of arsenic. The upper limit of linearity of the response for atomic absorption measurements is about 0.7ƒÊg. In use, the apparatus is fast and convenient to operate, enabling about forty determinations per hour

Biomonitoring of metal in children living in a mine tailings zone in Southern Mexico: A pilot study

Accumulation of metals in soil represents a health risk for individuals living near mining areas, especially for children who have a higher susceptibility to metal related diseases. The Taxco mining district in Southern Mexico was one of the largest Mexican metal producers of silver and gold, among other metals. The aim of this pilot study was to evaluate metal exposure on children aged 6-11 years living in and around the Taxco mine tailings zone. Lead in blood (PbB) was measured by graphite furnace atomic absorption spectrophotometry (AAS). Urine arsenic (AsU) was measured by hydride generation AAS, urinary Hg (HgU) by flow injection cold vapor atomic absorption, and urinary concentration of other metals such as chromium (Cr), nickel (Ni), cadmium (Cd), barium (Ba), cobalt (Co), copper (Cu), zinc (Zn), manganese (Mn), molybdenum (Mo), strontium (Sr), and iron (Fe) were determined by inductively coupled plasma optical emission spectrometry. Fifty samples were analyzed for PbB, AsU, and HgU, and 35 samples for the other metals. The mean concentration+/-SD for each metal was: PbB, 9.4+/-3.3 microg/dL; NiU, 75.4+/-30.7 microg/L; BaU, 18.4+/-4.1 microg/L; MnU, 5.2+/-0.7 microg/L; CuU, 29.6+/-6.8 microg/L; AsU, 16.5+/-8.3 microg/L; HgU, 0.7+/-0.86 microg/L; CdU, 4.7+/-2.7 microg/L; CrU, 15.1+/-4.45 microg/L; CoU, 18.3+/-9.7 microg/L; SrU, 49.2+/-30.7 microg/L; ZnU, 628.4+/-438.9 microg/L; FeU, 30.5+/-17.7 microg/L; and MoU, 52.1+/-29.3 microg/L. Results of this exploratory study show that children residing in the mining area of Taxco were environmentally exposed to several metals and a high percentage of these children had levels of Ni, Ba, Mn, Cr, Co, Cd, As, Hg, and Pb above reference values. Thus, further studies are needed to assess the effects of simultaneous exposure to toxic metals in children residing in mining areas.

Specific adsorption of arsenic and humic acid on Pt and PtO films

A study of specific adsorption of arsenic (As) and humic acid (HM) onto Pt and PtO films using cyclic voltammetry and cyclic massogram in 0.5-M H 2SO 4 is presented, which may serve as an alternative to studies involving specific adsorption of these species on soil minerals. Adsorption of As is normally evaluated by conducting batch adsorption experiments, followed by analysis using hydride-generation atomic absorption spectrophotometry (HGAA) or inductively coupled plasma-optical emission spectrometry (ICP-OES). We found that specific adsorption of As and HM depends both on the surface and on these species present in the adsorption solution. HM does not desorb previously adsorbed As at the HM concentrations used in the present study, but it does co-adsorb with As from a 1 × 10 −6-M aqueous solution of As 2O 3 containing 1 mg of carbon L −1 HM. Arsenic adsorbs strongly on Pt in the presence of HM or during sequential specific adsorption with HM.

Arsenic in Mexican Children Exposed to Contaminated Well Water

This cross-sectional study measures the arsenic level in school children exposed to contaminated well water in a rural area in México. Arsenic was measured in hair by hydride generation atomic absorption spectrophotometry. Overall, 110 children were included (average 10 years-old). Among 55 exposed children, mean arsenic level on hair was 1.3 mg/kg (range <0.006–5.9). All unexposed children had undetectable arsenic levels. The high level of arsenic in water was associated to the level in hair. However, exposed children drank less well water at school or at home than unexposed children, suggesting that the use of contaminated water to cook beans, broths or soups may be the source of arsenic exposure.

Hydride Generation Atomic Absorption Spectrophotometry Method for the Determination of Arsenic at Ultramicro Levels

A simple and rapid hydride generation atomic absorption spectrophotometry (HG – AAS) for the determination of arsenic in samples at very low concentrations has been developed. The method is based on the reaction of NaBH4 with acidified sample and separation of analyte as hydride from the matrix before determination. The arsine was transported to the quartz T-tube heated at 900°C for detection. The concentrations of HF solution used in the preparation of the samples were carefully controlled to avoid the formation of fluoro-complexed ions. The correlation coefficient (r2) was 0.989. The limit of detection, (LOD), was calculated as 0.71 μg g−1. The sensitivity of the method was found to be 0.000024 μg L−1. The method was applied successfully for the determination of arsenic in slurries from different sources and was found to be effective in the range 0.0002–2.35 μg L−1. Of all the ions tested, no ion was found to have a significant interference effect on the accuracy of the method.

Significance of urinary arsenic speciation in assessment of seafood ingestion as the main source of organic and inorganic arsenic in a population resident near a coastal area

In order to characterize the different sources of exposure to arsenic (As), urinary excretion of total As, the sum of inorganic As + MMA + DMA determined by the hydride generation-atomic absorption spectrophotometry technique, and the species As 3, As 5, monomethylarsonic acid (MMA), dimethylarsinic acid (DMA) and arsenobetaine were determined in 49 workers at a steel foundry, with presumed occupational exposure to As, and 50 subjects from the general population, all males. No evidence of occupational exposure to As resulted from environmental monitoring performed in the foundry, although the analysis of minerals used as raw materials showed the presence of As, particularly in fossils and fine ores. The urinary concentrations of As 3, MMA, DMA, the sum of inorganic As + MMA + DMA and total As were not different in the two groups, while arsenobetaine appeared significantly higher in the controls than in the workers. The different species of urinary As were all significantly correlated. Urinary excretion of As 3 was associated with the consumption of mineral water and with residence in an industrial zone, while MMA, DMA, arsenobetaine, the sum of inorganic As + MMA + DMA and total As urinary excretion were associated with the consumption of crustaceans and/or shellfish 3 days or less before urine collection. Multiple regression analysis confirmed these results. In conclusion, in populations with a high consumption of seafood, living in areas characterized by coastal/marine As pollution, only speciation of As can identify a prevalent role of environmental sources, like the consumption of seafood contaminated by As, in determining urinary As excretion, and exclude an occupational origin of the exposure.