High-resolution Continuum Source Atomic Absorption Research Articles

Efficiency of chemical generation of volatile species of zinc from non-acidic conditions

Chemical vapor generation (CVG) producing volatile species of zinc was carried out in a custom made generator with high-resolution continuum-source atomic absorption detection. The influence of composition of the reaction medium and various reaction modifiers was studied. The optimum conditions included neutral to basic pH of the reaction mixture, i.e., 0.1 M HCl and 0.5% (m/v) NaBH4 prepared in 0.1 M NaOH. Substantial improvement of generation efficiency (approx.18-times) was achieved with 8-hydroxyquinoline and a LOD of 4 ng mL−1 was obtained. The overall CVG efficiency of 2.7% was determined by comparison of sensitivity obtained with CVG and conventional solution nebulization (both coupled to inductively coupled plasma mass spectrometry) and 2.5% was determined by employing a radioactive isotope 65Zn. The described method is reasonably resistant to interferences, the greatest interference effect was observed with Bi(III) and Fe(III), other transition and noble metals interfered at a 100-times surplus over Zn and their effects decreased in the order Co(II) > Ni(II) > Cd(II) > Mn(II) > Ag(I) > Cr(III) > Cu(II). The accuracy of the method was verified by determination of zinc in the certified reference materials NIST 1643f (fresh water) and ERM CA713 (waste water).

Modified multi-walled carbon nanotubes as effective Pt(IV) ions adsorbent with respect to analytical application

Multiwalled carbon nanotubes were oxidized with 14.5 mol L−1 nitric acid and modified with (3-aminopropyl)triethoxysilane (APTES), N-[3-(trimethoxysilyl)propyl]ethylenediamine (TMPED) and N-[3-(trimethoxysilyl)propyl]diethylenetriamine (TMPDET). The obtained materials were widely characterized, tested as Pt(IV) ions adsorbents and used for enrichment of Pt(IV) ions from digested geological samples before Pt(IV) determination by high-resolution continuum source atomic absorption spectrometry. The oxidation of MWCNTs and their following modification with amine functional groups led to the significant changes of their porosity parameters, introduction of oxygen- or nitrogen-rich functional groups on the carbonaceous surface as well as the increase of structural defects in the graphene layers. The amine-modified CNTs effectively and quickly adsorbed Pt(IV) ions in a relatively wide pH range. In the case of CNTs-TMPED and CNTs-TMPDET adsorption equilibrium was achieved within 1 h, while in the case of CNTs-APTES 6 h were required. The maximum static adsorption capacity towards Pt(IV) ions was estimated to 79 mg g−1, 200 mg g−1 and 260 mg g−1 for CNTs-APTES, CNTs-TMPED, CNTs-TMPDET, respectively. CNTs-TMPDET was selected for the enrichment of platinum. The proposed analytical procedure was characterized by the enrichment factor of 375 and limit of detection equal to 1.32 ng g−1.

Assessment of palladium nanoparticles as chemical modifier for lead determination in leached extracts from petroleum waste by high-resolution continuum source atomic absorption spectrometry

ABSTRACT Palladium nanoparticles were evaluated as a potential chemical modifier for lead determination by high-resolution continuum source graphite furnace atomic absorption spectrometry. Hydrophilic palladium nanocubes and palladium nanospheres were synthesised with sizes varying from 3 to 22 nm. Positive effects in terms of sensitivity and thermal stability upon the use of palladium nanoparticles were observed, especially using the 3 nm spherical-shaped. The mass of modifier influenced the thermal stability and relative signal intensity of the analyte, although the effectiveness of the modifier appeared to be suppressed to an important extent in the presence of matrix components of the leached extracts obtained from petroleum wastes. The optimised pyrolysis and atomisation temperatures were, respectively, 800 °C and 2300 °C, using 200 ng of 3 nm palladium nanoparticles. The limit of detection (4 µg L−1) and the precision (better than 18 %) were considered satisfactory for the proposed analysis. The method accuracy, evaluated by recovery tests and by comparison with the results obtained using inductively coupled plasma mass spectrometry, was proven adequate to enable the determination of Pb in leached extracts from petroleum waste. The method was successfully applied to determine lead in leached extracts obtained from oily sludge and drill cuttings and the obtained concentrations ranged from <13 to 354.4 µg L−1.

Ultra-sensitive speciation analysis of tellurium by manganese and iron assisted photochemical vapor generation coupled to ICP-MS/MS

Photochemical vapor generation (PVG) of Te4+ was undertaken with a simple reactor consisting of a polytetrafluoroethylene reaction coil wrapped around a low-pressure mercury tube lamp and using a flow-injection for sample delivery. The composition of a reaction medium, the influence of irradiation time and the effect of added sensitizers and interferents were investigated using high-resolution continuum source atomic absorption spectrometry and a miniature diffusion flame atomizer. A mixture of 5 M acetic acid and 3.5 M formic acid and sample flow rate of 4 mL min−1 permitting a 36 s irradiation time were found optimal for PVG of Te4+. The addition of 250 mg L−1 Mn2+ and 15 mg L−1 Fe2+ ions as sensitizers enhanced the overall PVG efficiency 2.75-fold to 50 ± 2%. In order to achieve higher sensitivity necessary for determination of Te in real environmental samples, PVG was coupled to inductively coupled plasma triple quadrupole mass spectrometer and detection was performed with O2 in the reaction cell utilizing a mass shift mode of measurement (m/z 128 → m/z 144) to ensure interference free ion detection. A limit of detection 1.3 ng L−1 and repeatability (RSD) 0.9% at 250 ng L−1 were achieved. This ultrasensitive methodology was validated for speciation analysis of Te in water samples of various matrix complexities (fresh water, well water, seawater and contaminated water). Since no response was observed from Te6+ under optimal PVG conditions, Te4+ was selectively determined by direct PVG. The sum of Te4+ and Te6+ was determined after pre-reduction of Te6+ in 6 M HCl (95 °C), evaporation to dryness and reconstitution in the reaction medium containing sensitizers. Very good accuracy was demonstrated by spiked recoveries for both Te4+ and total Te in water samples and also by total Te determination in fresh water Standard Reference Material NIST 1643f.

Determination of Cu and Mn in Seawater by High-Resolution Continuum Source Graphite Furnace Atomic Absorption Spectrometry

The conditions for the determination of copper and manganese in seawater by high-resolution continuum-source graphite furnace atomic absorption spectrometry (HR-CS GFAAS) were optimized. The analytical properties were compared with those of low-resolution line source GFAAS (LR-LS GFAAS). The metrological characteristics were estimated considering the dilution of the sample and optimization of the temperature program of the electrothermal atomizer. Using HR-CS GFAAS, the elements were determined in undiluted samples, while LR-LS GFAAS allows the determination only at double dilution. The lower limits of determined Cu concentrations almost coincided for both versions of GFAAS. For manganese, the limits of detection and quantification were significantly lower for HR-CS GFAAS. Calibration curves were plotted using standard solutions. The proposed scheme was tested on water samples from the Sea of Okhotsk by standard addition. The detection limits (LODs) were 0.6 µg L−1 for copper and 0.07 µg L−1 for manganese by HR-CS GFAAS and 0.5 µg L−1 for copper and 0.13 µg L−1 for manganese by LR-LS GFAAS.

Evaluation of soil contamination by heavy metals at public cemeteries in the municipality of Lages, southern Brazil

ABSTRACT The burial of bodies is a potentially polluting activity. Taking this into consideration, the aim of the present study was to verify the compliance of two cemeteries with environmental legislation and to quantify the concentrations of heavy metals in soils affected by burial activities. Physicochemical characterization of the soil was performed by analyzing control samples from areas near the cemeteries. Concentrations of cadmium, lead, chromium, nickel, zinc and copper were determined using high-resolution continuum source atomic absorption spectrometry. The two cemeteries had unsatisfactory properties for the retention of metal cations, with clay percentages ranging from 15.40 to 41.40% and sand percentages ranging from 28.75 to 66.85%. The control samples presented low cation exchange capacity (12.27 to 22.73 cmolc/dm³) and high aluminum (Al3+) saturation (66.74 to 90.16%). Although neither of the two cemeteries had concentrations above the limits established for the metals analyzed by Resolution No. 420/2009 of the National Environment Council, the contaminants may be leaching to groundwater due to inadequate soil characteristics.

Modern Methodological Approaches to Sample Preparation for the Determination of Trace Elements in Food Products and Plant Raw Materials

Introduction. Various copper compounds are most widely used as plant protection agents in agriculture. From a hygienic point of view, information on excessive accumulation of copper in plants related to the use of a specific formulation of copper-containing pesticides is of interest. Our objective was to assess feasibility of increasing statistical significance of results of determining low residue levels of a copper-containing pesticide in apple samples by flame atomic absorption spectrometry using a high-resolution spectrometer in combination with developed approaches to sample preparation of plant-based foods, including homogenization with dry ice and microwave mineralization. Materials and methods: We analyzed 30 samples of apples collected in three different agro-climatic zones by flame atomic absorption spectrometry and electrothermal atomization atomic absorption spectrometry. Both methods were validated on 10 samples with added copper at levels 1-5 of the lower limit of quantitation. A statistical calculation was performed based on a simple Student’s test to assess the significance of differences between the results of measurements by flame and electrothermal techniques. Homogeneity of variances was estimated using the Fisher test to clarify the possibility of comparing two data sets. Results: The use of a technique of cryo-grinding and microwave decomposition in a microwave reactor in combination with a high-resolution continuum source atomic absorption spectrometry demonstrated a decrease in scattering and the limit of detection and better repeatability in the analysis of parallel samples. Results of statistical calculations confirmed the homogeneity of variances in data samples obtained for electrothermal and flame techniques, and the further Student’s t-test showed insignificant differences between the results of measurements obtained by FAAS and ET-AAS. Conclusion: Our findings prove that modern methods of sample preparation in combination with highly sensitive equipment allow a significant reduction in the limit of detection and scattering of test results.

High-Resolution Atomic Absorption Spectrometry Combined With Machine Learning Data Processing for Isotope Amount Ratio Analysis of Lithium.

An alternative method for lithium isotope amount ratio analysis based on a combination of high-resolution atomic absorption spectrometry and spectral data analysis by machine learning (ML) is proposed herein. It is based on the well-known isotope shift of approximately 15 pm for the electronic transition 22P←22S at around the wavelength of 670.8 nm, which can be measured by the state-of-the-art high-resolution continuum source graphite furnace atomic absorption spectrometry. For isotope amount ratio analysis, a scalable tree boosting ML algorithm (XGBoost) was employed and calibrated using a set of samples with 6Li isotope amount fractions, ranging from 0.06 to 0.99 mol mol-1, previously determined by a multicollector inductively coupled plasma mass spectrometer (MC-ICP-MS). The calibration ML model was validated with two certified reference materials (LSVEC and IRMM-016). The procedure was applied toward the isotope amount ratio determination of a set of stock chemicals (Li2CO3, LiNO3, LiCl, and LiOH) and a BAM candidate reference material NMC111 (LiNi1/3Mn1/3Co1/3O2), a Li-battery cathode material. The results of these determinations were compared with those obtained by MC-ICP-MS and found to be metrologically comparable and compatible. The residual bias was -1.8‰, and the precision obtained ranged from 1.9 to 6.2‰. This precision was sufficient to resolve naturally occurring variations, as demonstrated for samples ranging from approximately -3 to +15‰. To assess its suitability to technical applications, the NMC111 cathode candidate reference material was analyzed using high-resolution continuum source atomic absorption spectrometry with and without matrix purification. The results obtained were metrologically compatible with each other.

Extraction induced by emulsion breaking to assay Cr, Cu and Mn in asphalt samples by high-resolution continuum source atomic absorption spectrometry and its comparison with other sample preparation methods

This paper reports the development of a method based on the extraction induced by emulsion breaking (EIEB) for the determination of Cr, Cu and Mn in asphalt by high-resolution continuum source atomic absorption spectrometry. In optimized conditions, the extraction efficiency ranged from 88.6 for Cu to 104.5% for Mn. Measurements were carried out at the primary lines of the three analytes. The limits of detection were 0.02 μg g−1 for Cr, 0.01 μg g−1 for Cu and 7.11 ng g−1 for Mn. The precision, expressed as the relative standard deviation, ranged from 1.0 for Cu to 9.1% for Cr. The performance of the proposed method was compared to previously reported sample preparation procedures, including microwave-assisted acid digestion (MW-AD), ultrasound-assisted acid extraction (USE), emulsification (E), and direct dilution in organic solvent (DD). The parameters evaluated were matrix effects, limits of detection and quantification, characteristic mass, precision, accuracy, sample stability and applicability for routine analysis. The methods most suitable for Cu determination were EIEB, MW-AD, USE and E. For Cr and Mn, the best results were obtained by EIEB, MW-AD and DD procedures.

Heavy metals assessment in the major stages of winemaking: Chemometric analysis and impacts on human health and environment

Wine contamination with heavy metals may pose long-term human health risks and environmental damages. This study evaluated the frequently detected heavy metals (HMs): Cr-Chromium, Fe-Iron, Cu-Copper, Mn-Manganese, Ni-Nickel and Zn-Zinc in the winemaking stages of white (Grasă de Cotnari) and red (Fetească neagră) wine varieties. Samples from wines and wastewaters were collected at eight different winemaking stages and HMs quantification was done by high-resolution continuum source atomic absorption spectrometry. Results showed that, in white wines Pb, Cu and Cr concentrations decreased during winemaking processes, while in red wines only Pb and Cu levels were reduced. A progressive increment was observed for Ni and Fe in white wines and for Cr, Ni and Fe in red wines, during winemaking. In the final winemaking stage of white wines, Fe and Mn concentrations were 3826 and 1493 μg/L, respectively, while in red wines, 1136 and 1256 μg/L, respectively. Analysis of wines consumption safety was performed according to the estimated daily intake (EDI) and target hazard quotients (THQ). EDI values of the analysed white wines ranged from 0.0032 to 6.2217, and for red wines from 0.0004 to 2.6919. THQ values below 1 suggested that moderate wine consumption does not have negative impacts on human health.

Efficient photochemical vapor generation of bismuth using a coiled Teflon reactor: Effect of metal sensitizers and analytical performance with flame-in-gas-shield atomizer and atomic fluorescence spectrometry

Photochemical vapor generation (PVG) of bismuth was accomplished in a simple flow–injection system with a standard Hg low-pressure tube lamp and a coiled Teflon reactor. The influence of a reaction medium flow rate (irradiation time) and composition was investigated using a miniature diffusion flame atomizer and high-resolution continuum source atomic absorption spectrometry. Combination of 40% (v/v) acetic acid, 1.25% (v/v) formic acid and a metal sensitizer at a flow rate of 3 mL min−1 (irradiation time of 90 s) was found optimal. The use of various metals as sensitizers was studied to initiate and enhance PVG substantially. The evident positive effect was found for four metal cations and the enhancement effect was in the following order: Cu2+<Cd2+<Fe2+ ≪ Co2+. At 50 mg L−1 Co2+ as the sensitizer, the overall PVG efficiency of 54 ± 2% was determined from relative comparison of sensitivities obtained with PVG and liquid nebulization coupled simultaneously to inductively coupled plasma mass spectrometry. In order to reach low limits of detection (LOD) at low operation cost, a coupling of PVG to atomic fluorescence spectrometry was tested and conditions of atomization in two flame atomizers were optimized. A blank-limited LOD of 12 ng L−1 was obtained with an advanced flame-in-gas-shield atomizer, which competes with PVG coupled to inductively coupled plasma mass spectrometry (5 ng L−1). Interferences from commonly used inorganic acids (HNO3, HCl and H2SO4) and other elements (As3+, Pb2+, Sb3+, Se4+ and Te4+) were also investigated and the accuracy was verified by analysis of water Standard Reference Material NIST 1643f.

Determination of residual dimethyl sulfoxide by high-resolution continuum source graphite furnace molecular absorption spectrometry

High-resolution continuum source molecular absorption spectrometry (HR-CSMAS) has been extended to the determination of sulfur-containing organic molecule, on the example of dimethyl sulfoxide (DMSO) as a residual solvent in CH3NH3PbI3 perovskite thin films. For this purpose, DMSO molecules were converted into CS molecules by pyrolysis in a graphite furnace at low temperature and the sulfur content was determined by measuring molecular absorption of CS at 258.055 nm. An aqueous solution of DMSO was used for calibration. A characteristic mass of 17 ng was achieved for S after pyrolysis at 160 °C by using Pd as a chemical modifier. Furthermore, the content of DMSO was normalized to that of Pb whereas the content of Pb was determined by reducing the Pb in the perovskite to metallic Pb with Zn powder and measuring absorption of the weak Pb line at 261.418 nm by high-resolution continuum source atomic absorption spectrometry (HR-CSAAS). The Pb content remained constant whereas the S/Pb molar ratio decreased with increasing annealing time. Our results open new opportunities for the characterization of residual DMSO in wide classes of materials.

Simultaneous determination of Ba, Co, Fe, and Ni in nuts by high-resolution continuum source atomic absorption spectrometry after extraction induced by solid-oil-water emulsion breaking

This paper describes the simultaneous determination of Ba, Co, Fe, and Ni in nuts by high-resolution continuum source atomic absorption spectrometry after extraction induced by solid-oil-water emulsion breaking. Extraction yields ranged from 94.9 for Ba to 109.8% for Fe. Simultaneous measurements were carried out at secondary lines of Ba, Co, Fe, and Ni. The limits of detection and quantification were, respectively, 3.819 and 1.146 mg L−1 for Ba, 2.274 and 7.421 µg L−1 for Co, 0.095 and 0.285 mg L−1 for Fe, and 2.138 and 6.614 µg L−1 for Ni. The precision ranged from 3.1 to 4.2%, 1.5 to 8.0%, 1.6 to 6.6%, and 0.4 to 6.1% for Ba, Co, Fe and Ni, respectively. The method accuracy was assessed by recovery tests and comparison of the results obtained by the proposed extraction method with those obtained after acid digestion. Recoveries ranged from 93.5 for Ni to 104.5% for Co.

Assessment and zoning of environmental hazard of heavy metals using the Nemerow integrated pollution index in the vineyards of Malayer city

The purpose of the present study was to evaluate and zoning the environmental hazards of heavy metals in the soil using the Nemerow integrated pollution index in vineyards (vineyards) of Malayer city. In this study, after consecutive visits to the study area and reviewing the map of the area, sampling operations were performed in January 2019. Soil sampling was performed based on a systematic random method. A total of 286 samples were collected from topsoil (depth 0 to 20 cm). Of these, 157 samples were located in agricultural lands (gardens and agricultural land) and 129 samples in natural areas (pastures and barren lands). The samples were analyzed by high-resolution continuum source atomic absorption spectrometry (HR-CS AAS) and using the flame method. The average concentrations of Cu, Mn, Zn, Cr, As, Ni and Hg are 87.86, 597, 109, 67.12, 47.1, 84.32, and 0.344 mg/kg, respectively. These values are lower than the NIPI index values for these metals. The results showed that there is a positive and significant correlation between Cu and Mn, Cu and zinc, Cu, and As as well as As and Ni. There is also a significant negative correlation between Cu and Hg, As and the electrical conductivity (EC) as well as As and Mn. At present, these soils are not at serious risk of soil contamination with heavy metals.

Metal Homeostasis and Gas Exchange Dynamics in Pisum sativum L. Exposed to Cerium Oxide Nanoparticles.

Cerium dioxide nanoparticles are pollutants of emerging concern. They are rarely immobilized in the environment. This study extends our work on Pisum sativum L. as a model plant, cultivated worldwide, and is well suited for investigating additive interactions induced by nanoceria. Hydroponic cultivation, which prompts accurate plant growth control and three levels of CeO2 supplementation, were applied, namely, 100, 200, and 500 mg (Ce)/L. Phytotoxicity was estimated by fresh weights and photosynthesis parameters. Additionally, Ce, Cu, Zn, Mn, Fe, Ca, and Mg contents were analyzed by high-resolution continuum source atomic absorption and inductively coupled plasma optical emission techniques. Analysis of variance has proved that CeO2 nanoparticles affected metals uptake. In the roots, it decreased for Cu, Zn, Mn, Fe, and Mg, while a reversed process was observed for Ca. The latter is absorbed more intensively, but translocation to above-ground parts is hampered. At the same time, nanoparticulate CeO2 reduced Cu, Zn, Mn, Fe, and Ca accumulation in pea shoots. The lowest Ce concentration boosted the photosynthesis rate, while the remaining treatments did not induce significant changes. Plant growth stimulation was observed only for the 100 mg/L. To our knowledge, this is the first study that demonstrates the effect of nanoceria on photosynthesis-related parameters in peas.

On-line electrochemical preconcentration and electrochemical hydride generation for determination of antimony by high-resolution continuum source atomic absorption spectrometry

Trace concentrations of antimony in aquatic samples were determined by high resolution continuum-source atomic absorption spectrometry (HR-CS AAS) after electrochemical pre-concentration and electrochemical hydride generation. Antimony was electrochemically deposited in a microporous glassy carbon electrode as elemental antimony then was electrochemically converted at the same electrode surface to antimony hydride which was transported by argon gas to the quartz cuvette of the spectrometer. The detection limit and precision of the method are below 0.1 μg L−1 and 3–5%, respectively. The method was employed for the determination of antimony in a CRM and water samples including surface, underground and waste water.

Generation of tellurium hydride and its atomization in a dielectric barrier discharge for atomic absorption spectrometry

Atomization of tellurium hydride in a dielectric barrier discharge (DBD) atomizer was investigated for the first time. First, the conditions of hydride generation were optimized with the use of a miniature diffusion flame atomizer and high-resolution continuum source atomic absorption spectrometry. Generation efficiency of more than 90% was determined from a comparison of the response to solution nebulization with inductively coupled plasma mass spectrometry. Subsequently, atomization of tellurium hydride in a plane-parallel configuration of the DBD atomizer was optimized. Argon was found as the best carrier gas under a flow rate of 75 mL min−1 while the peak-to-peak high voltage was 18 kV. A limit of detection of 56 ng L−1 (3σ, n = 15) and repeatability (RSD) of 2.8% at 5 μg L−1 were reached. The accuracy and applicability of this methodology was verified by analysis of water Standard Reference Material NIST 1643f and two model samples of tap and stream water. Laser-induced fluorescence was employed to investigate a spatial distribution of free Te atoms and to estimate atomization efficiency in the DBD. Significant fractions of free Te atoms were identified all over the length of the optical tube of the DBD atomizer covered by the electrodes and atomization efficiency of up to 100% was quantified. A feasibility of tellurium hydride in-situ collection in the DBD atomizer was studied and collection efficiency of around 50% was found promising for further studies.

Extraction induced by emulsion breaking for simultaneous determination of Co, Fe and Ni in petroleum asphalt cement by high-resolution continuum source atomic absorption spectrometry

This paper reports, for the first time, the simultaneous determination of Co, Fe and Ni in petroleum asphalt cement by high-resolution continuum source atomic absorption spectrometry after extraction induced by the emulsion breaking method. The variables that could influence the sample preparation were evaluated, like sample dilution with toluene and mineral oil, extraction time, HNO3 and Triton X-100 concentration in the aqueous extractant solution. At optimized conditions, 0.08 g of the sample was dissolved with 1.5 mL of toluene and 3.5 mL of mineral oil and vigorous mixed with the extractant solution containing 40% (v/v) of HNO3 and 40% (v/v) of Triton-X-100. The emulsions were broken by heating just after their formation and the aqueous extracts were collected for analysis. Simultaneous determination was carried out at the secondary lines of Co (352.685 nm), Fe (352.604 nm) and Ni (352.454 nm). For this purpose, the best pyrolysis and atomization temperatures were 700 and 2400 °C, respectively. Calibration was performed with standard aqueous solutions and no matrix effects were observed. The limit of detection was 0.003 mg L−1 for Co, 0.018 mg L−1 for Fe and 0.027 mg L−1 for Ni. Method accuracy was confirmed by comparing the results obtained by the proposed extraction method with those obtained after samples acid digestion. Recoveries ranged from 100 to 107%, 103 to 109% and 95.5 to 98.9% were obtained for Co, Fe and Ni, respectively.

Oilseeds from A Brazilian Semi-Arid Region: Edible Potential Regarding the Mineral Composition.

Oilseeds from five native plant species with edible potential from the Brazilian Caatinga semi-arid region (Diplopterys pubipetala, Barnebya harleyi, Croton adamantinus, Hippocratea volubilis, and Couroupita guianensis) were investigated regarding their mineral contents. The minerals, Na, K, Ca, Mg, Fe, Cu, Cr, Al, were analyzed by high-resolution continuum source atomic absorption spectrometry (HR–CS AAS) and P by the vanadomolybdophosphoric acid colorimetric method. K, Mg, and P were the main elements found (1.62–3.7 mg/g, 362–586 µg/g, and 224–499 µg/g dry weight (dw), respectively). B. harley seeds contained the highest amounts of K and P, while C. guianensis seeds were the richest in Mg. Fe was the most abundant oligoelement (2.3–25.6 µg/g dw). Cr contents were below the limit of quantification for all samples and Al amounts were low: 0.04–1.80 µg/g dw. A linear discriminant analysis clearly differentiated B. harleyi and C. guianensis samples from the remaining ones. In sum, these oilseeds from the Brazilian Caatinga semi-arid region seem to have the potential to be used as natural sources of minerals, mainly K.

High-resolution continuum source atomic absorption spectrometry: a review of current applications

Atomic absorption spectrometry (AAS) is one of the most widely used and available methods for analysis of substances and materials. It allows one to determine about 70 elements from the periodic table and is characterized by rapidity, high accuracy and sensitivity, as well as simplicity of analytical techniques. A feature of AAS is simultaneous determination of only one element due to the use of a measurement design with a line source (hollow-cathode lamps, high-frequency electrodeless lamps, optical quantum generators, etc.). To make AAS more competitive, the first commercially available continuum source atomic absorption spectrometer was designed in 2004. Unique analytical capabilities of the new instruments found application first of all in the analysis of food, pharmaceuticals, waste and drinking water, oil and petrochemicals, biological objects, etc. This review covers publications on the application of continuum source AAS in analytical chemistry and provides a development outlook of the method.