Cold Vapor Atomic Absorption Spectrometry Research Articles

Study of mercury release in dental amalgam wearers by measuring salivary and urinary mercury

Background. Mercury amalgam remains the most effective and least expensive dental filling material. Mercury is considered by the World Health Organization (WHO) as one of the ten chemicals or groups of chemicals that are extremely concerning for public health. The aim of our study is to assess exposure to mercury from dental amalgams through the measurement of salivary and urinary mercury. Population and methods. This is a prospective, analytical study carried out at the National Toxicology Center of Algiers during the year 2004. The study included 48 subjects with dental amalgams and 12 subjects without amalgams. Mercury levels in saliva and urine were measured by cold vapor atomic absorption spectrometry using the "Flow Inject Mercury System". Results. Compared to other studies, the urinary mercury values in our study are relatively high. This observation is also true for our controls. For salivary values, our subjects have levels (after chewing) that remain within the same range. The comparison of urinary and salivary means shows a significant difference between subjects with three or more amalgams and controls. There is also a significant correlation between the number of fillings and salivary concentrations. Among all amalgam bearers, there is no significant correlation between urinary and salivary concentrations. Elevated levels were noted in our controls compared to foreign studies, indicating probable general exposure (food, atmosphere, etc.). Conclusion. There is a real exposure to mercury from dental amalgams, but is this exposure harmful to the health of the bearers? This risk remains "acceptable" as long as we stay below the accepted limits. It is necessary to protect at-risk groups (pregnant and breastfeeding women, children, and adolescents) from this exposure.

Mercury in Selected Abiotic and Biotic Elements in Two Lakes in Poland: Implications for Environmental Protection and Food Safety

Mercury, which tends to bioaccumulate and biomagnify in aquatic food webs, poses a potential health risk to wildlife and to consumers of predatory fish in particular. Its concentration in biota can be high even at low environmental concentrations. Therefore, the aim of this study was to determine mercury in both abiotic (water and sediment) and biotic elements (common reed (Phragmites australis) and fish: pike (Esox lucius), bream (Abramis brama) and roach (Rutilus rutilus)) in the context of assessing the pollution of two lakes in Poland and the safety of fish consumers. The possibility of Hg biomagnification in fish was also considered. Mercury was determined by means of cold vapor atomic absorption spectrometry (CVAAS). The concentrations of Hg in water and bottom sediments of Lake Ińsko were lower than in Lake Wisola. In the bottom sediments of both lakes, a positive correlation was found between the Hg content and organic matter. The concentration of mercury in the organs of common reed did not exceed 0.017 mg/kg dry weight (dw), and its distribution can be presented as follows: root > leaves > stems > rhizomes. In fish organs from both lakes, the average mercury content did not exceed 0.086 mg/kg of wet weight (ww) and in most cases it was the highest in pike. Higher values were only observed in the muscles and skin of roach. This indicates a lack of biomagnification in the relationships between planktivorous-predatory and benthivores-predatory fish. Based on the maximum levels of mercury in fish and the calculated parameters, i.e., estimated daily intake (EDI), target hazard quotient (THQ) and tolerable weekly intake (TWI), the muscles of the examined fish were found to be safe for consumption. The average dietary exposure to total mercury (THg) and methylmercury (MeHg) was below 0.3% of the TWI.

Quality of Phosphate Rocks from Various Deposits Used in Wet Phosphoric Acid and P-Fertilizer Production.

Phosphate rocks (PRs) play a crucial role in ensuring the availability of phosphorous for the world's food needs. PRs are used to manufacture phosphoric acid in the wet process as well as P-fertilizers. The chemical and mineralogical compositions of PRs from Djebel Onk (Algeria), Khneifiss (Syria), Negev (Israel), Bou Craa (Morocco), and Khouribga (Morocco) are discussed in this study. PRs were characterized by inductively coupled plasma optical emission spectrometry (ICP-OES), cold vapor atomic absorption spectrometry (CVAAS), ion chromatography (IC), and X-ray diffraction (XRD), as well as gravimetric and potentiometric methods. All PRs were mainly composed of CaO, P2O5, SiO2, F, SO3, Na2O, MgO, Al2O3, Fe2O3, SrO, and K2O at the level of wt.%. The P2O5 content accounted for 28.7-31.2%, which indicates that these are beneficial rocks to a marketable product. The degree of PR purity expressed by the minor elements ratio index (MER index) varied from 2.46% to 10.4%, and the CaO/P2O5 weight ratio from 1.6 to 1.9. In addition, the occurrence of trace elements such as As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, Ti, V, U, and Zn, as well as Cr(VI) and Cl ions at the level of mg∙kg-1 was found. Since PRs will be used to produce P-fertilizers, their composition was compared with the regulatory parameters set up by EU Regulation 2019/1009 related to the heavy metals (As, Cd, Pb, Ni, Hg, Cu, Zn) and Cr(VI) contents in inorganic fertilizers. The heavy metals and Cr(VI) content in all PRs did not exceed the limit values. XRD analysis revealed that fluorapatite, hydroxyapatite, carbonate fluorapatite, and carbonate hydroxyapatite were the dominant minerals. The accuracy and precision of the used methods were evaluated by analysis of standard reference materials (SRM) for Western Phosphate Rock (NIST 694). The recovery was 85.3% for U and 109% for K2O, and the RSD ranged from 0.67% to 12.8%.

Elution behavior of mercury in desulfurization gypsum produced in a coal-fired power plant

Batch and semi-batch elution tests were conducted to determine the elution pattern and dissolvable amount of mercury in desulfurization gypsum produced in a coal-fired power plant. Two gypsum samples obtained from double-contact-flow-type desulfurization equipment were used. Chemical forms of mercury in gypsum were identified by temperature programmed desorption–cold vapor atomic absorption spectroscopy. The elution behavior of mercury varied significantly with the testing method. In the batch elution test, an industrial standard method, mercury eluted into the water rapidly and was then adsorbed by gypsum. This behavior was kinetically simulated with the sequential elution and adsorption of mercury, showing the maximum elution peak. In contrast, in the semi-batch method, the adsorption phenomenon was negligible, and the ultimate amount of eluted mercury could be determined. Thus, the semi-batch method is more accurate for evaluating mercury elution from desulfurization gypsum.

Determination of Heavy Metal Residues in Tropical Fruits near Industrial Estates in Rayong Province, Thailand: A Risk Assessment Study

This study determined the extent of heavy metal contamination of local fruit in Rayong, Thailand, an area where an industrial base is adjacent to agricultural areas. Dietary exposure to agricultural products grown in contaminated areas can cause multiple adverse effects to the human body. In order to avoid such undesirable effects, concentrations of heavy metals [arsenic (As), cadmium (Cd), copper (Cu), mercury (Hg), lead (Pb), and zinc (Zn)] were investigated in popular tropical fruits from three districts of Rayong, namely Wang Chan, Klang and Mueang. The levels of heavy metals were determined by inductively coupled plasma-mass spectrometry (ICP-MS) and cold vapor-atomic absorption spectrometry (CV-AAS). Levels of the six heavy metals in sampled fruits (durian, jackfruit, pineapple, rambutan, long kong, and mangosteen) were in the range of 0.0004-6.7095 mg/kg; 16.7% of fruit samples exceeded maximum permissible limits of Pb. Based on health risk assessments, values of estimated daily intake (EDI) were less than those of maximum tolerable daily intake. However, for non-carcinogenic risks, high hazard index (HI) values were found in some markets while for carcinogenic risks (CRs), CR values of three fruits (durian, jackfruit, and mangosteen) exceeded acceptable levels. Therefore, long-term fruit consumption could impact health of local consumers. These results provided insight into the need for regular monitoring of heavy metal concentrations in potentially contaminated fruits and for prevention of its potential effects.

Comparability assessment of the results of thiomersal quantification in adsorbed immunobiological medicinal products by colourimetry and by cold vapor atomic absorption spectrometry

To ensure the quality of immunobiologicals, it is required to quantify the thiomersal preservative present in a number of them. The authors have previously developed an analytical procedure for thiomersal quantification in non-adsorbed immunobiological medicinal products, which is based on cold vapor atomic absorption spectrometry (CV AAS). The aim of the study was to analyse the possibility of using the CV AAS procedure for thiomersal content determination in adsorbed immunobiologicals and evaluate the comparability of thiomersal quantification results obtained by colourimetry and CV AAS. Materials and methods: the study used the national reference standard of mercury ions content and the pharmacopoeial reference standard of thiomersal content in adsorbed medicinal products (PhRS 3.1.00427), as well as samples of immunobiologicals by different manufacturers: a DTP vaccine, anatoxins, hepatitis B and influenza vaccines, and combined vaccines. The study involved CV AAS and the colourimetric reaction between mercury and dithizone. Results: the specificity of the CV AAS procedure is demonstrated by the coefficient of variation (3.95%) and the coefficient of correlation between the test sample volume and thiomersal content (0.9956). The regression analysis and the Fisher’s test value of 0.16 indicate the absence of bias. The trueness of the method is satisfactory, as the percent recovery differs from the total spiked amount by less than 10%. For the sensitivity of the CV AAS procedure, its quantification and detection limits are 6.9×10-3 μg/ mL and 2.3×10-3 μg/ mL, respectively. The Fisher’s test value obtained in the comparability assessment of the results of thiomersal quantification by colourimetry and CV AAS (1.29) is lower than the conventional tabulated one (3.96). Conclusions: according to the study, it is possible to use the CV AAS procedure for thiomersal quantification in adsorbed immunobiologicals. The established detection limit allows evaluating residual amounts of thiomersal in in-process intermediates during the production of preservative-free immunobilogical dosage forms. The comparability assessment of the results of thiomersal quantification by colourimetry and CV AAS, carried out using oneway ANOVA and Fisher’s test, showed the possibility of using PhRS 3.1.00427 to control the consistency of operation when reproducing the CV AAS procedure.

Ultra-trace determination of mercury by platinum-coated tungsten coil trapping cold vapour atomic absorption spectrometry

ABSTRACT Within the scope of this study, a simple, highly sensitive and rapid trapping method for the determination of mercury (Hg) was developed. In this method, the surface of the tungsten coil (W-coil) was coated with platinum using the electrolytic deposition technique. Scanning electron microscopy–energy-dispersive X-ray analyses were performed to examine the surface morphology of Pt-coated W-coil. During the experiment, firstly, Hg vapour generated by tetrahydroborate, used as a reducing agent, was efficiently trapped on the Pt-coated W-coil at collection temperature in hydrochloric acid medium. Subsequently, Hg trapped on the surface of the Pt-coated W-coil was revolatilised by the effect of releasing-stage gases at the optimised releasing temperatures and transported to quartz T-tube atomiser. The experimental conditions have been optimised. Under the optimised conditions, a limit of detection (LOD) of 8.8 ng L−1 was obtained using three times the standard deviation of blank values using Pt-coated W-coil trap cold vapour atomic absorption spectrometry (CVAAS) system. The precision of the measurements was evaluated by relative standard deviation of 4.4%, which is obtained by 11 consecutive measurements of reagent blanks for a collection volume of 6.83 mL corresponding to 90 s collection. The enhancement factors for both LOD (3 s) and characteristic concentration (Co) were found to be 5.09 and 5.02 when compared with the regular CVAAS system without trap. The accuracy of the proposed method was evaluated by analysing BCR 146 R (Sewage sludge), RTC (Sandy Loam 7), ERM-BD151 (skimmed milk powder) and NIST 1641e (mercury in water) certified reference materials (CRMs). There was a good agreement between certified and found values for all CRMs. The results of the application of the developed method in seawater showed the spike recovery ranges from 94.2% to 102.4%.

Determination and speciation of methyl mercury and total mercury in fish tissue samples by gold-coated W-coil atom trap cold vapor atomic absorption spectrometry

A sensitive analytical technique was developed where gaseous mercury formed by sodium tetrahydroborate reduction is transported to and trapped on a resistively heated gold-coated Tungsten-coil atom trap for in situ preconcentration. This technique was applied successfully for determination and speciation of methyl mercury and total mercury in some fish tissue samples (liver, muscle and gill) obtained from Muğla province. The analytical parameters were optimized both for trap and no-trap studies. Under the optimized conditions, a limit of detection (LOD) of 6.0 ng/L was obtained. The precision was evaluated by relative standard deviation (RSD%) corresponding to 4.1% (n = 11). Accuracy of the proposed method was evaluated by analyzing “DOLT:5 Dogfish Liver”, “NIST SRM 1640a Trace elements in natural water” and “NIST 1946 Lake Superior fish tissues”. The measurements of the certified reference materials were in good agreement with the certified values at the 95% confidence level.

Analytical chemistry in technical approaches: immobilization of biosorbent waste containing heavy metals in cemented materials

An ecologically safe and economically justified method of stabilization of the used biosorbents was developed. Sorbent contaminated with heavy metals has been successfully solidified/stabilized using a hydraulic binder. The test results indicated that up to 1% of the biosorbent residue used could be added without compromising the compressive strength of the mortar. The compressive strength of the modified mortars did not change significantly even after 20 freeze/thaw cycles. The analytical methods such as Flame Atomization-Atomic Absorption Spectrometer, Graphite Furnace-Atomic Absorption Spectrometer, and Cold Vapor-Atomic Absorption Spectrometry were utilized to examine the leaching behavior of selected heavy metals during harsh condition exposure. The leachability of selected heavy metals was found to be below the limit allowed by the US EPA after immersion and agitation for 10 days in artificial water solutions (seawater, groundwater, and rainwater). X-Ray Diffraction and Brunauer–Emmett–Teller data showed no significant changes in the crystalline structure and surface area of the modified mortars after treatment. Research showed that mixing the adsorbent used with mortar was effective in immobilizing heavy metals and allowed the implementation of a so-called ‘zero waste’ management method.Graphical abstract

Evaluation of mercury content in combustible tobacco products by employing cold vapor atomic absorption spectroscopy and considering the moisture content: a comprehensive study

Plants are mainly made up of water, which constitutes between 80 and 90% of their weight. Moisture factor comes across as one of the most important in tobacco products. Rapid determination of moisture content in tobacco products comes at necessity in any tobacco management plants (before and after production). Therefore, the concern has been raised in this study to evaluate the moisture content in four kinds of combustible tobacco products using the gravimetric method. In addition, a total mercury content using cold vapour atomic absorption spectroscopy has been evaluated in all chosen combustible tobacco products in this study. Determining moisture content in four types of tobacco products does not show significant differences within a product group. Moisture content ranged from 7.9% in bidis to 25% in pipe tobaccos. Mercury content in tobacco ranged from 13 µg/kg to 32 µg/kg while in cigarette wrapper paper and filter from the limit of detection (LOD) < 1.3 µg/kg to 8.2 µg/kg. As evidenced, cigarette wrapper paper and filters alone are unlikely to be a significant source of consumer exposure to mercury. However, the proposed sample preparation method provides good results for the preparation of specific material, such as tobacco products.Graphical abstract

Mercury content in beetroot and beetroot-based dietary supplements

Total mercury (THg) concentrations in fifty-four beetroot-based DSs and seven lots of conventional and organic beetroots (divided into unpeeled, peeled, and skins) were determined by direct thermal decomposition-gold amalgamation cold vapour atomic absorption spectrometry. The analytical procedure was optimised and validated. The recovery (%) for Hg was 101.9 and 92.73 in BCR-463 and DOLT 4, respectively. The intermediate precision value (4.7%) exceeded the repeatability value, which was as expected. The estimated LOD and LOQ values of the analytical procedure used were 0.096 and 0.29 [ng], respectively, and were converted to corresponding MDL and MQL values, which were 0.96 and 2.9 [ng/g], respectively. The highest contents of THg were found in conventional (28.03 ng/100 g w.w.) and organic (56.2 ng/100 g w.w.) beetroot or powder supplements (0.65 ng/g). Statistical analysis confirmed the differentiation of the analysed group of products at the level of significance 0.05 and 0.001. There were found statistically significant relationships in terms of: dietary supplement-beetroot (p < 0.001), beetroot-part of vegetable (p < 0.05) and dietary supplement-pharmaceutical form (p < 0.05). In conclusion, the analysed DSs did not pose a significant risk for a consumer in terms of permissible contamination limit, Provisional Tolerable Weekly Intake realisation, and the Target Hazard Quotient.

A Comparison of Conventional and Ultrasound-Assisted BCR Sequential Extraction Methods for the Fractionation of Heavy Metals in Sewage Sludge of Different Characteristics.

The purpose of this study was to determine the heavy metal (HM: Cd, Cr, Cu, Ni, Pb, Zn, and Hg) content in particular chemical fractions (forms) of sewage sludge with different characteristics (primary and dewatered sludge) using conventional (CSE) and ultrasound-assisted (USE) BCR sequential extraction methods (Community Bureau of Reference, now the Standards, Measurements and Testing Programme). The concentrations of HMs were determined using inductively coupled plasma optical spectrometry (ICP-OES). Only mercury was assayed with cold vapor atomic absorption spectrometry (CVAAS). Ultrasound treatment was conducted in the ultrasonic bath (Sonic 5, Polsonic). The optimal sonication time (30 min) was determined using ERM-CC144 (Joint Research Center; JCR) certified reference material. The conducted experiment revealed that the use of ultrasound waves shortened the extraction time to 4 h and 30 min (Stages I to III). The recoveries (RM) of heavy metals ranged from 62.8% to 130.2% (CSE) and from 79.8% to 135.7% (USE) for primary sludge, and from 87.2% to 113.2% (CSE) and from 87.8% to 112.0% (USE) for dewatered sludge. The only exception was Hg in dewatered sludge. The conducted research revealed minor differences in the concentrations and fractionation patterns for Cd, Ni, and Zn extracted from sludge samples by the tested methods. However, it was confirmed that the above findings do not significantly affect the results of a potential ecological risk assessment (with minor exceptions for Cd and Zn in the primary sludge), which is extremely essential for the natural use of sludge, and especially dewatered sludge (the final sludge). The shorter extraction time and lower energy consumption prove that ultrasound-assisted extraction is a fast and simple method for HM fractionation, and that it provides an alternative to the conventional procedure. Therefore, it can be considered a “green method” for the assessment of the bioavailability and mobility of heavy metals in solid samples.

The Elemental Profile of Beer Available on Polish Market: Analysis of the Potential Impact of Type of Packaging Material and Risk Assessment of Consumption.

Twenty-five elements, including the most essential and toxic metals, were determined in fifty beer samples stored in cans and bottles by Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) and Cold Vapor Atomic Absorption Spectroscopy (CVAAS) techniques. The packaging material was analyzed using the Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM-EDS) technique. The control of the level of individual metals is necessary, not only to maintain the organoleptic properties of the product, but also to fulfill the standards regarding the permissible maximum concentrations. Metals can originate from different sources, including the brewing water, malt grains, hops, adjuncts, fruits, and spices. They may also come from contamination from the brewery equipment, i.e., vessels and tanks, including beer packing, storing and transporting (kegs, casks, cans). Discriminant analysis revealed that the differentiation of three types of beer (Lager, Ale, Craft) was possible, based on elemental concentrations, for the reduced data set after their selection using the Kruskal-Wallis test. The analysis of the impact of the packaging material (can or bottle) proved that when this parameter was used as a differentiating criterion, the difference in the content of Na, Al, Cu and Mn can be indicated. The risk assessment analysis showed that the consumption of beer in a moderate quantity did not have any adverse effect in terms of the selected element concentrations, besides Al. However, in the case of Al, the risk related to consumption can be considered, but only for the beer stored in cans produced from aluminum.

Analysis of Heavy Metal (Hg, Pb, Ni) Content in Marsh Clam, Polymesoda expansa Collected from Butuan Bay, Philippines

Butuan Bay is an amalgamation of resources and wastes, with the Agusan River as its main river source. Multiple industrial operations near the area make it susceptible to pollution, thereby affecting the aquatic organisms and the people who depend on the bay for food and livelihood. Thus, the main objective of the study was to determine the Mercury (Hg), Lead (Pb), and Nickel (Ni) concentration in the flesh of Marsh clam (Polymesoda expansa) in different mangroves wetlands across Butuan Bay. Heavy metal concentration was assessed using cold vapor atomic absorption spectroscopy for Hg and Atomic Absorption Spectrophotometry for Pb and Ni. The results revealed that Hg and Pb concentrations were below the detection limits (BDL), while Ni concentrations were within the tolerable limits established for bivalves. Human health risk via the consumption of P. expansa was calculated using the estimated daily intake (EDI) and Target Quotient Hazard (THQ). Results show that the EDI of Ni exceeded the oral reference dose, but its THQ was below the standard THQ value. In conclusion, the consumption of P. expansa does not pose any adverse health effects on human health. Still, further investigation and monitoring of the mangrove ecosystems are encouraged to secure the environment's health and the communities that depend on it.

Risk Assessment of Total Mercury (T-Hg) in Commercial Seafood Marketed in Bangkok, Thailand

Seafood is recognized as the high protein source of human consumption. However, it is hampered by mercury contamination. The objectives of this study are to determine total mercury (T-Hg) levels in edible portions of commercial seafood available in Bangkok’s supermarkets, and to evaluate the potential risks from mercury through seafood consumption. Total 32 species, including 22 fish, 4 cephalopod and 6 shellfish, were purchased from super-markets. Fish samples were dissected in 3 parts comprised of flesh, gill and viscera. While, cephalopod and shellfish were separated for edible tissues. The samples were digested in hot acid and were determined using cold-vapor atomic absorption spectrometry technique. The results revealed that T-Hg contained in the fish flesh &gt; cephalopod &gt; shellfish. In addition, T-Hg was accumulated in flesh &gt; viscera &gt; gill. Statistical analysis suggested that T-Hg accumulated in flesh was related positively with species, feeding habit, and habitat (p &lt; 0.05). For risk analysis, estimated daily intake (EDI) of flesh ranged from 0.01 to 0.42 µg kg-1 bodyweight d-1, the lowest and highest EDI values were in salmon and yellowfin tuna, res-pectively. Yellowfin tuna, narrow-barred Spanish mackerel, fourfinger threadfin, and silver sillago were the 4 species that having the EDI values of T-Hg higher than the FAO/WHO recommended provisional tolerable daily intake (PTDI) of 0.23 µg kg-1 bodyweight d-1. Thus, the frequent consumption of these seafood are not recommended. In addition, the daily consumption of seafood should not exceed the maximum safe daily intake (MSDC). The MSDC of seafood in this study ranged from 15.5 (yellowfin tuna) to 474 (salmon) g d-1.

A new analytical method based on Co-Mo nanoparticles supported by carbon nanotubes for removal of mercury vapor from the air by the amalgamation of solid-phase air removal

Heavy metals are a major cause of environmental pollution, and mercury is a well-known toxicant that is extremely harmful to the environment and human health. In this study, new carbon nanotubes coated with cobalt and molybdenum nanoparticles (Co-Mo/MWCNT) were used for Hg0 removal from the air by the amalgamation of solid-phase air removal method (ASPAR). In the bench-scale setup, the mercury vapor in air composition was produced by the mercury vapor generation system (HgGS) and restored in a polyethylene airbag . In optimized conditions, the mercury vapor in the airbag passed through Co-Mo/MWCNT and was absorbed on it. Then, the mercury was completely desorbed from Co-Mo/MWCNT by increasing temperature up to 220 °C and online determined by cold vapor atomic absorption spectrometry (CV-AAS). The recovery and capacity of Co-Mo/MWCNT were obtained at 98% and 191.3 mg g-1, respectively. The Repeatability of the method was 32 times. The mercury vapors absorbed on Co-Mo/MWCNT adsorbent could be maintained at 7 days at the refrigerator temperature. The Co-Mo/MWCNT as a sorbent has many advantages such as; high capacity, renewable, good repeatability and chemical adsorption (amalgamation) of mercury removal from the air. The method was successfully validated by MCA and spiking of real samples.

Use of selective quenching of a photoluminescent probe based on a Eu(III) β-diketonate complex for determination of methylmercury in produced water after liquid-liquid extraction

An Eu(III) β-diketonate complex was produced and employed as a photoluminescent probe to determine methylmercury (CH3Hg+). To establish its molecular structure, the Eu(III) complex was characterized by elemental (CHNS) and thermogravimetric analyses and infrared spectroscopy. After establishing robust conditions to use the Eu(III) complex as an analytical probe, it was employed for the analysis of produced water (PW) samples with the analytical response based on the luminescence suppression proportional to the concentration of CH3Hg+ (a linear model after normalization of the response within the concentration range from 0.2 μg L−1 up to 2.0 μg L−1). Selectivity was guaranteed by a simple liquid-liquid extraction of the analyte in dichloromethane, which also allowed a 50 times pre-concentration factor. The instrumental limit of quantification of 0.2 μg L−1 is equal to the limit established in Brazilian resolution for total mercury content in waters, but pre-concentration (50 times factor) improved the overall method limit of quantification down to 4 ng L−1. Recovery results agreed with the ones achieved using cold vapor atomic absorption spectrometry.

Case studies on longitudinal mercury content in humpback whale (Megaptera novaeangliae) baleen

Quantification of contaminant concentrations in baleen whales is important for individual and population level health assessments but is difficult due to large migrations and infrequent resighings. The use of baleen allows for a multiyear retrospective analysis of contaminant concentrations without having to collect repeated samples from the same individual. Here we provide case studies of mercury analysis using cold vapor atomic absorption spectroscopy in three individual humpback whales (Megaptera novaeangliae), a 44.5-year-old female and two males aged ≥35 and 66 years, over approximately three years of baleen growth. Mercury concentrations in the female's baleen were consistently 2–3 times higher than in either male. Age did not affect mercury concentrations in baleen; the younger male had comparable levels to the older male. In the female, mercury concentrations in the baleen did not change markedly during pregnancy but mercury did spike during the first half of lactation. Stable isotope profiles suggest that diet likely drove the female's high mercury concentrations. In conclusion, variations in baleen mercury content can be highly individualistic. Future studies should compare sexes as well as different populations and species to determine how the concentrations of mercury and other contaminants vary by life history parameters and geography.

The content of lead, cadmium, arsenic, mercury and tin in fruit and their products based on monitoring studies - exposure assessment.

Fruit and fruit products are important part of our daily diet. In addition to the ingredients necessary for the proper functioning of the body, these products can also be a source of intake elements harmful to human health. Analysis of the results of monitoring studies conducted in Poland in 2015 concerning contamination of lead (Pb), cadmium (Cd), arsenic (As), mercury (Hg) and tin (Sn) in fruit and fruit products and exposure assessment. Approximately 600 samples of fresh, frozen, dried fruits, fruit preserves and canned fruits were tested. The laboratories of State Sanitary Inspection were involved in testing. Accredited and validated analytical methods were used. The test samples were prepared in accordance with the standard PN-EN 13804:2013. The contents of lead, cadmium and tin were determined by using flame atomic absorption spectrometry (FAAS) or flameless with electrothermal atomization spectrometry (GFAAS); arsenic by using hydride generation atomic absorption spectrometry method (HGAAS) and mercury the "cold vapor" atomic absorption spectrometry (CVAAS) method. Contamination of investigated samples with elements harmful to human health (Pb, Ca, As, Hg and Sn does not rise concern to human health and was in most cases comparable with contamination reported in other European Union countries. The estimated average exposure of adults and children to lead intake with fruit and fruit products ranged from 0.5% to 14.6% of the respective Benchmark Dose Lower Confidence Limit (BMDL) established by the European Food Safety Authority (EFSA). The mean intake of cadmium with these groups of foodstuffs was in the range 0.3 - 8.5% of the TWI value (Tolerable Weekly Intake) established by EFSA for adults and children (0.1 - 3.6% of the PTMI (Provisional Tolerable Monthly Intake) established by JECFA. In case of arsenic mean intake was in the range 0.5 - 1.6% BMDL whilst for mercury (inorganic form) intake represented 0.5 - 1.4% of TWI value established by JECFA and then confirmed by EFSA. Based on the obtained results, it was found that content of Pb, Cd, As, Hg and Sn in the tested samples of fruit and their products does not pose a risk to consumer health. Estimated exposure of consumers does not exceed tolerable doses established by EFSA and JECFA for these elements.

Optical fiber mercury biosensor based on immobilized urease and bromothymol blue onto the alginate-chitosan membrane in the flow-system

An optical fiber biosensor has been developed for the detection of mercury ion based on inhibition of urease immobilized onto alginate–chitosan membrane, coupled with bromothymol blue (BTB) in the flow system. To get a good performance of the biosensor toward Hg(II) ion detection, the experimental parameters of the biosensor were optimized. Here, the maximum wavelength was detected at 580 nm, with the optimum response at pH of 6. The calibration curve had a dynamic working range at 10 to 500 μg/L of Hg(II) ion with a detection limit of 12.1 μg/L biosensor has been performed by the addition of 1 mM ethylenediaminetetraacetic acid (EDTA) solution, in which five-time cycles have been achieved with the inhibition decrease to 9.94% from the original biosensor response. Applying the biosensor to the real samples showed conformity of results with the reference method, cold vapor atomic absorption spectrometry (CV-AAS). Therefore, this biosensor can be used as a method for routine analysis in the determination of Hg(II) concentration in an aqueous sample.