Zeeman Atomic Absorption Spectrometry Research Articles

Mercury contamination of two e-waste recycling sites in Ghana: an investigation into mercury pollution at Dagomba Line (Kumasi) and Agbogbloshie (Accra).

This study investigated mercury pollution at two e-waste recycling sites in Ghana-Dagomba Line in Kumasi and Agbogbloshie in Accra. A total of 129 soil samples taken at 100m and 50m resolutions, respectively, for Dagomba Line and Agbogbloshie, were analysed for mercury using a Zeeman atomic absorption spectrometry. Mercury concentrations from the recycling sites (ranging from 0.11 to 7.57mg/kg Dagomba Line, and 0.01-4.36mg/kg at Agbogbloshie) were significantly higher than that of the surrounding areas (0.01-0.17mg/kg in Kumasi and 0.01-2.18mg/kg in Accra) and unpolluted control sites (0.05mg/kg in Kumasi and 0.02mg/kg in Accra). The dismantling sites at both locations had the highest mercury concentrations. Furthermore, the concentrations were significantly higher at the Dagomba Line site in Kumasi than at Agbogbloshie, even though the Dagomba Line site is relatively recent. The mercury concentrations at both sites exceeded the pollution prevention and abatement level of 0.1mg/kg. However, the estimated human health risk showed no potential human health effects. Moreover, the mercury concentrations in water and sediment (0.12-7.69ng/L and 0.02-0.28ng/L for Dagomba Line and Agbogbloshie, respectively) were below the US EPA standards. Findings from this study show that e-waste recycling can contaminate the topsoil with mercury, irrespective of the scale of the activity.

Automatic monitors for direct continuous mercury measurement in ambient air, hydrocarbon, and industrial gases

Abstract. Mercury (Hg) has various sources of natural and anthropogenic emissions, can be transferred for a long distance in the atmosphere, and accumulate in deponent media and food chains. Due to its toxicity, mercury is considered a global pollutant. The Minamata Convention on Mercury (Articles 19 and 22) stipulates mercury monitoring to obtain information on the environmental cycle, transport, deposition, transformation, and fate of mercury and mercury compounds in various ecosystems. The developed monitors based on Zeeman atomic absorption spectrometry allow the fully automatic real-time determination of mercury in such different media as ambient air, industrial, and process gases.

A Two-Stage Probe Atomizer for Zeeman Atomic Absorption Spectrometry with High-Frequency Modulation of Radiation Polarization

A two-stage probe atomizer for direct analysis of samples that strongly smoke when evaporating (oil, food suspensions, etc.) by Zeeman atomic absorption spectrometry with high-frequency modulation of the polarization of the transmission radiation has been proposed. The effective ventilation of the atomizer and independent heating of the tungsten probe in a strong magnetic field of the atomizer have been provided for sensitive detection of atomic absorption pulses without overlapping of the transmission beam by the probe. The performance of the atomizer has been illustrated on the MGA-915MD spectrometer by the behavior of the signals of the Ag and Al test elements depending on the heating modes, probe position, and diameter of the dosing hole of a graphite furnace. The range of concentrations to be determined has been extended by a factor of 50, while maintaining an error at a level that is acceptable for quantitative analysis.

Двухстадийный зондовый атомизатор для зеемановской атомно-абсорбционной спектрометрии с высокочастотной модуляцией поляризации излучения

AbstractA two-stage probe atomizer for direct analysis of samples that strongly smoke when evaporating (oil, food suspensions, etc.) by Zeeman atomic absorption spectrometry with high-frequency modulation of the polarization of the transmission radiation has been proposed. The effective ventilation of the atomizer and independent heating of the tungsten probe in a strong magnetic field of the atomizer have been provided for sensitive detection of atomic absorption pulses without overlapping of the transmission beam by the probe. The performance of the atomizer has been illustrated on the MGA-915MD spectrometer by the behavior of the signals of the Ag and Al test elements depending on the heating modes, probe position, and diameter of the dosing hole of a graphite furnace. The range of concentrations to be determined has been extended by a factor of 50, while maintaining an error at a level that is acceptable for quantitative analysis.

MERCURY IN THE SEDIMENT OF THE UPPER PARNAÍBA RIVER

ABSTRACT The contamination of aquatic environments with chemical trace elements can be evaluated by their accumulation in sediments of the water body. Studies on mercury require the use of exclusive extraction techniques that have relatively high costs when compared to the analysis of other trace elements. This study was conducted aiming at determining the mercury concentration in sediments of the Upper Parnaiba River basin, located in a region of agricultural expansion between the states of Piaui and Maranhao. The sediment was collected at 12 sites in the basin. After drying, the quantification of total mercury was performed by the Zeeman atomic absorption spectrometry coupled to a pyrolysis reactor. Mercury concentrations in sediments of the Parnaiba River ranged from 4.2 to 58.5 ng g−1 and presented a low probability of adverse effects on biota. Mercury had no correlation with the variables clay, silt, sand, total organic carbon, iron, and aluminum, demonstrating its possible anthropogenic origin. Although mercury concentrations have a low probability to disturb the balance of the local ecosystem, there is a need for monitoring the region in order to quantify the risks to biota and human health.

Mercury concentrations in terrestrial fossil vertebrates from the Bauru Group (Upper Cretaceous), Brazil and implications for vertebrate paleontology

In this study we determined total mercury concentrations (THg) in a set of fossils from the Upper Cretaceous Bauru Group, Brazil, and investigated how the incorporation of this element occurs in fossil organisms and in their paleoenvironment. The analyzed fossil specimens were collected from two different locations (Jales and Fernandópolis) of the Adamantina Formation and correspond to samples of teeth, bones, osteoderms, and crocodylomorph eggs (probably laid by Baurusuchidae), and their associated sediments. The samples were submitted to Zeeman atomic absorption spectrometry, showing concentrations ranging from approximately 5 ng.g−1 to 77 ng.g−1 in biomineral matrix. The results show mild fluctuations of Hg concentration in the different types of fossils analyzed, with teeth and bones retrieving more Hg than osteoderms, thus being the most suitable for this type of analysis. Adult specimens of Baurusuchidae showed ∼30% more Hg than juvenile ones in their biomineralized tissues, which points to a continuous process of Hg accumulation throughout the individual's life history. As for the determination of Hg in sedimentary rocks, which has been previously claimed to be an indication of the relationship between volcanic activities and some mass mortality events (MMEs), the analysis of Hg in fossils can furnish additional information for future studies regarding the relationship between disturbances in the Hg cycle triggered by volcanic emissions and MMEs. Additionally, the results also suggest that the concentration of Hg in fossil vertebrates can be used as a tool for discussions about ontogenetic stages and, in some very particular cases, identification of female individuals.

基于塞曼原子吸收法的燃煤电厂汞排放监测研究

基于塞曼原子吸收法的燃煤电厂汞排放监测研究

Assessing the Target Hazard Risks of Cadmium Pollutant due to Consumption of Aquatic Biota and Food Snack Among School Children in Tallo Coastal Area of Makassar

Background and Objective: Cadmium is used extensively in various industrial processes in the city of Makassar, South Sulawesi, as a results it potential lead to hazard pollutions both to the environment and to the human being. This study aimed to assess the potential target hazard risks of cadmium due to consumption of aquatic biota and food snack among school children in Makassar Coastal areas. Materials and Methods: This study applied an analytic observational study used a cross sectional approach design and target hazard risk assessment approach. Investigation of Cd in aquatic system for surface water, sediment, shells and crab and in terrestrial for surface soil and school snack were commenced for Cd level concentrations. Then, Target Hazard Quotient (THQ) was calculated to find out whether the Cd contaminated food consumed by school children in school have exceeded the allowable standard or still safe to be consumed.Thematerials used are hot plate, glassware commonly used in laboratory and spectrophotometer absorption graphite furnace (Hitachi Z-5000 polarized Zeeman atomic absorption spectrometry). Results: This study revealed that Cd concentration in aquatic system for surface water, sediment, shell and crab were 0.016 mL L^-1, 0.026, 0.012 and 0.023 mg g^-1, respectively. Furthermore, Cd concentration in terrestrial system for surface soil, school snack and ambient air were 0.0411 mL m^-3, 0.016 and 0.006 mg g^-1, respectively. All values resulted from the laboratory test were exceeded the acceptable level stated both by World Health Organization and Health Ministry of Republic of Indonesia with 0.01 mL LG1 for water,0.001 mg gG1 for aquatic biota and school snacks, except for sediment with 70 mg gG1 that still below the standard, respectively. The risk quotient value for THQ due to consume shell and crab were 0.0046 and 0.0011, respectively whereas THQ value for consuming cake in the school was 0.0025. Those values indicated that no risks exist since it still <1 or consumption of those aquatic biota and snacks still save. Conclusion: To sum up, the concentration of Cd both in aquatic and terrestrial system have been exceeded the allowable level for environmental standard, although the THQ values still below than 1, that means still safe for all those food to be consumed.

Euthyroid Sick Syndrome and Nutritional Status are Correlated with Hyposelenemia in Hemodialysis Patients

Maintenance hemodialysis (HD) patients have altered levels of thyroid hormone (TH) in euthyroid sick syndrome, along with low T3 levels and several nutritional metabolic disturbances. Selenium (Se) is an essential trace element for living organisms, which has been shown to play a major role in thyroid hormone levels and the nutritional metabolism. The aims of the present study were to assess the changes in serum levels of selenium and their correlation with disorders of the endocrine and nutritional metabolism in HD patients. Fifty-three uremic patients with hemodialysis were evaluated; 30 healthy volunteers served as controls. Baseline serum concentrations of total triiodothyronine (TT3), free triiodothyronine (FT3), total thyroxine (TT4), and free thyroxine (FT4) were determined by radioimmunoassay (RIA). Serum levels of thyroid-stimulating hormone (TSH) and intact parathyroid hormone (iPTH) were measured by a sensitive immunoradiometric assay (IRMA). Serum selenium was analyzed using Hitachi Z- 2000 polarized Zeeman atomic absorption spectrometry. Other metabolic variables were measured in all patients and control subjects. Multiple correlation analysis was performed among variables. Higher serum triglyceride, LDL-C, ApoB and lower albumin, HDL-C levels were found in subjects with HD. Mean serum selenium concentration was significantly lower in the HD group than in the control group (p<0.01). The levels of serum TT3 and FT3 in HD patients were significantly lower than in healthy control subjects (p<0.01; p<0.05, respectively), but TT4, FT4 and TSH were not different. However, serum iPTH levels were significantly higher in patients than in controls (p<0.01). In the group of HD patients, serum selenium levels were significantly positively correlated with albumin, HDL-C, TT3 and FT3 ; and negatively correlated with triglyceride (TG), LDL-C, ApoB and iPTH. Both serum TT3 and FT3 levels were significantly positively correlated with HDL-C; and negatively correlated with TG, LDL-C and ApoB. These data suggest that hyposelenemia in HD patients correlated with euthyroid sick syndrome with low T3 levels, and nutritional status with hyperlipidemia and hypoalbuminemia which might be involved in dysfunction in the endocrine and nutrition metabolism in dialysis patients.

Mercury Pollution Exploration in Latvia with High-Sensitivity Zeeman Atomic Absorption Spectrometry

Mercury Pollution Exploration in Latvia with High-Sensitivity Zeeman Atomic Absorption Spectrometry This research presents Hg pollution measurements performed in Latvia with sensitive method using Zeeman AAS analyzer RA-915+ and necessary attachments. Air in Riga city and water samples from a number of rivers and lakes of Latvia were analyzed for presence of low-level Hg concentrations. Ombrotrophic bog peat was analyzed to get insight into long-term trends. Environment in the sites sampled is relatively clean according to the results obtained, but there are local spots of pollution.

Determination of Rare-Earth Elements in Rare-Earth Magnets by Polarized Zeeman Flame Atomic Absorption Spectrometry

Rare-earth elements are essential materials for manufacturing high-performance products. Wasted home appliances are called mines ; there are many parts that contain rare metals, such as rare-earth elements. For effective recycling, it is necessary to measure the rare-earth elements in urban mines. The measurement conditions of the rare-earth elements with polarized Zeeman atomic absorption spectrometry were optimized. In the presence of ethanol and potassium nitrate, sensitivities of rare-earth elements were improved, and no interference of coexisting iron. Rare-earth magnets were chosen as an example of urban mines. In rare-earth magnets, Nd, Dy, Pr, Gd and Sm were measured by polarized Zeeman atomic absorption spectrometry. Spike recoveries were obtained from 90 to 110%. Rare-earth elements in rare-earth magnets could be measured satisfactorily.

Chemotherapy targeting regional lymphatic tissues to treat rabbits bearing VX2 tumor in the mammary glands

Lymph node status is one of the decisive prognostic factors in breast cancer. Chemotherapy targeting regional lymphatic tissues has emerged as a promising approach for the treatment of malignancies with high tendency to disseminate lymphatically. In this study, rabbits bearing well-developed VX2 tumors in the mammary gland received carboplatin-activated carbon suspension (CP-CH) administered subcutaneously (s.c.), carboplatin solution (CP-Sol) s.c., CP-Sol intravenously (i.v.), or a sham therapy, respectively, 6 weeks after tumor implantation. The platinum concentrations in breast tumors, axillary lymph nodes, and distant metastases were determined by Zeeman atomic absorption spectrometry (AAS). Therapeutic effects were assessed in terms of tumor and node volume ratio, cell proliferation and necrosis. Compared to CP-CH or CP-Sol s.c., CP-Sol i.v. exhibited more strong cytotoxic efficacy on breast tumor and distant metastases. In contrast, CP-CH s.c. produced much higher drug concentrations and more evident antitumor activities in axillary nodes, as demonstrated by the inhibited node growth, declined mRNA level of proliferating cell nuclear antigen (PCNA), and more extensive tumor necrosis. Based on these data, we recommend lymphatic chemotherapy to be used as an effective component of the approach to the systemic treatment on breast cancer patients with positive lymph nodes.

Direct determination of selenium in rat blood plasma by Zeeman atomic absorption spectrometry

The method was developed to be applied for direct determination of selenium in rat plasma by graphite-furnace atomic absorption spectrometry with Zeeman background correction. Blood was obtained from CD ® rats of both sexes 2 h after dosing in weeks 7 and 13 in order to acquire data on the levels of selenium in these animals during 13-week gavage administration of l-seleno-methylselenocysteine (SeMC), a new candidate chemopreventive agent under development. Application of the commonly used method of standard addition was found to be unsuitable to calculate the selenium content in rat plasma (within-run and between-run accuracy and precision parameters were less than 85%). Therefore, a new analytical method was developed. In this method, samples of rat plasma (50 μL) were diluted 10-fold with a reducing agent containing l-ascorbic acid, a modifier solution containing palladium chloride and Triton X-100. Samples were atomized in pyrolytically coated graphite tubes and peak height signals were measured. Selenium concentrations were determined by linear least squares regression analysis based on the standard curve generated in pooled rat blank plasma. Since selenium is normally present in plasma, a three-step approach was used to calculate selenium plasma levels. Initially selenium levels were determined based on the standard curve with selenium-spiked pool plasma. In the second step, background selenium levels in the pooled plasma were determined based on the same standard curve. In the third step, background level was added to the previously derived number. The relative errors were in the range from −4.6 to 11.4% (intra-day assay) and from −0.4 to 8.8% (inter-day assay) which proved good accuracy. The relative standard deviations were in the range from 1.88 to 4.70% (intra-day precision) and from 3.28 to 5.38% (inter-day precision). In rat plasma, the following dose-dependent selenium levels (mean ± S.D.) in males and females, respectively, were observed at 13 weeks: 655.5 ± 48.8 and 595.8 ± 43.9 ng/mL (control group), 927.9 ± 85.3 and 859.3 ± 164.3 ng/mL (0.4 mg/kg per day dose group), 1238.9 ± 182.4 and 1169.9 ± 112.6 ng/mL (0.8 mg/kg per day dose group), and 1476.5 ± 138.1 and 1320.1 ± 228.6 ng/mL (2.0 mg/kg per day dose group). No significant sex differences in selenium plasma levels were seen in the SeMC-treated groups. No significant differences in selenium plasma levels were seen between mean plasma levels at 7 and 13 weeks. The described method is simple, rapid, accurate, precise and can be easily applied in other laboratories for a large number of samples.

Determination of trace elements in aquatic plants by means of solid sampling Zeeman atomic absorption spectrometry (SS-ZAAS)

Direct solid sampling Zeeman atomic absorption spectrometric methods were developed and successfully applied to the determination of mercury, cadmium, lead and manganese in aquatic plants. Mercury was determined using a specially designed furnace. The other elements were determined by a third generation spectrometer. In 3-field- and dynamic mode the working range was substantially extended and high amounts of analyte were detectable without laborious dilution of solid samples. The measurements were based on calibrations using certified reference materials of organic origin. No matrix effects were observed under the optimised conditions. Results obtained were in good agreement with the certified values.

Monochromatization of resonance radiation in Zeeman atomic absorption spectrometry

Two methods of background correction in atomic absorption spectrometry with nonselective atomic effects are investigated: first, with a source possessing a continuous spectrum and, second, that of correction based on the Zeeman effect. The parameters of the monochromator, which was developed expressly for Zeeman atomic absorption spectrometry, are considered.

Validation of mercury determination by solid sampling Zeeman atomic absorption spectrometry and a specially designed furnace

Certified reference materials (CRMs) of different origin were used to validate the direct determination of total mercury by solid sampling Zeeman atomic absorption spectrometry (SS-ZAAS) and a specially designed furnace. The temperature program provides only for one step. Atomisation of mercury and pyrolysis of the matrix is performed at a constant temperature in the range of 900–1000 °C. Calibration points achieved by CRMs and aqueous solutions are covered by one calibration line, indicating the absence of matrix effects. Relatively high amounts of chlorine, known for causing problems in mercury determination do not influence analytical results. The excellent accuracy of the method results in a very good agreement with the certified values. The precision of SS-ZAAS measurements in a range from 0.5 to 50 ng Hg does not exceed 3% R.S.D. A limit of quantification of 0.008 μg g −1 Hg was achieved.

Determination of Hg, Cd, Mn, Pb and Sn in seafood by solid sampling Zeeman atomic absorption spectrometry

Direct solid sampling Zeeman atomic absorption spectrometric methods were developed and applied to the determination of mercury, cadmium, manganese, lead and tin in seafood. All elements but mercury were measured by a third generation Zeeman atomic absorption spectrometry combined with an automatic solid sampler. In 3-field- and dynamic mode the calibrations concentration range was substantially extended and high amounts of analyte were detectable without laborious dilution of solid samples. The measurements were based on calibrations using certified reference materials of organic matrices. In case solid certified reference materials were not available calibration by aqueous standard solutions was proved to be an alternative. No matrix effects were observed under the optimized conditions. Results obtained were in good agreement with the certified values. Solid sampling Zeeman atomic absorption spectrometry proved to be a reliable, rapid and low-cost method for the control of trace elements in seafood.

Establishment of SI-traceable reference values for the content of various elements in the IMEP-14 sediment sample

For the first time in the International Measurement Evaluation Programme (IMEP)-14, a sediment sample was offered to analytical laboratories to perform measurements of As, Cd, Cr, Cu, Fe, Pb, Hg, Ni, U and Zn. In line with IMEP policy, the results were presented according to the certified / assigned reference values established by several reference laboratories around the world. The certification campaign is described in detail. Isotope dilution mass spectrometry was applied as a primary method of measurement, whenever possible, to achieve SI-traceable results. For reference measurements of As, Fe, Hg and Zn, k0-neutron activation analysis and Zeeman atomic absorption spectrometry were applied. The reference values (ranges) were characterised as ”certified” (for Cd, Cr, Pb, Ni and U) or ”assigned” (for As, Cu, Fe, Hg and Zn) according to IMEP policy. The measurement uncertainty of the certified / assured reference values was calculated according to the ISO/BIPM Guide.

Validated method for the determination of platinum from a liposomal source (SPI-77) in human plasma using graphite furnace Zeeman atomic absorption spectrometry.

A sensitive analytical method based on flameless atomic absorption spectrometry with Zeeman correction has been validated for the quantitative determination in human plasma of platinum originating from cisplatin in a liposomal source, SPI-77. The performance of the method was acceptable over a sample concentration range of 0. 125-1.25 micromol platinum/L and the lower limit of quantification was determined to be 1.25 micromol platinum/L in undiluted clinical samples. The performance data of the assay were investigated using both a calibration curve with carboplatin in plasma ultrafiltrate and diluted human plasma samples spiked with SPI-77. The recoveries, between-day and the within-day precisions of both methods of calibration were not significantly different allowing carboplatin ultrafiltrate calibration standards to be used to quantify platinum derived from SPI-77 in human plasma. Apparently, the liposomal formulation had no significant influence on the determination of platinum. The usefulness of the presented method was demonstrated in a phase I clinical and pharmacokinetic study. In addition, in vitro experiments were carried out to determine the distribution of SPI-77 in blood. The results indicated that platinum from SPI-77 mainly concentrates in plasma and that binding to and/or endocytosis in red blood cells is negligible.

Determination of silicon using electrothermal Zeeman atomic absorption spectrometry in presence of some transition metals as modifiers

The transition metals ions Cr(III), Mn(II), Fe(III), Co(II), Ni(II), and Zn(II) in addition to Ca(II) have been used as modifiers in the determination of silicon using electrothermal Zeeman atomic absorption spectrometry. Co(II) proved to be the best. Graphite tubes treated with zirconium, in the presence of Co(II) as a modifier, exhibit higher sensitivity by a factor of five than untreated tubes. The modifier concentration and ashing and atomization temperatures have been optimized. Also interference of different inorganic cations and anions was studied.