Multi-element Graphite Furnace Atomic Absorption Research Articles

Quantitation of Toxic Elements in Various Water Samples by Multi-element Graphite Furnace Atomic Absorption Spectrometry

Quantitation of Toxic Elements in Various Water Samples by Multi-element Graphite Furnace Atomic Absorption Spectrometry

Multi-Element Determination of Cu, Mn, and Se using Electrothermal Atomic Absorption Spectrometry

Simultaneous multi-element graphite furnace atomic absorption spectrometer (SIMAA 6000) is used to get a new multi-element determinations methodology for Cu, Mn, and Se. Firstly, the optimum conditions for single-element mode are determined (which include: pyrolysis and atomization temperatures). Secondly, the optimum conditions for multi-element mode are also determined. The conditions in the two modes have been compared in terms of the characteristic masses, detection limits and pyrolysis and atomization temperatures. The effect of the matrix on the determination has been studied using urine standard sample from Seronorm (LOT 0511545). The accuracy of the developing methods has been confirmed by analysis different biological reference materials. Simultaneous multi-element GF-AAS offers a rapid, low cost and sensitive method for the analysis of trace elements.

Concentration Levels of Trace Elements in Carrots, Onions, and Potatoes Cultivated in Asopos Region, Central Greece

The objective of the work was to investigate the correlation between the environmental pollution of Asopos river area in Viotia, Greece and the concentration of Ni, Cr, Cd, Pb, Cu, and As in specific crops (carrots, onions, and potatoes) produced in this region. Samples of these crops from Asopos and other Greek areas (control) were collected. For method accuracy, the Certified Reference Material, CRM 281 (trace elements in rye grass) was measured. Simultaneous multi-element graphite furnace atomic absorption spectrometry was used after a microwave acid digestion. The levels of Ni in Asopos food were found up to 9 times higher than control (e.g., Asopos potatoes had an average Ni content of 800 µg/kg compared to 78 µg/kg in control, whereas Asopos carrots had an average Ni content of 474 µg/kg compared to 93 µg/kg in control). Likewise, the levels of Cr were found to be about 2 times higher than control (e.g., Asopos carrots were found to have an average Cr content of 43 µg/kg compared to 20 µg/kg in control). The levels of Cd and Pb had a high variance in the Asopos sourced food. Arsenic was not detected in any sample. Our results indicate that the mean intake of trace elements (Ni, Cr, Pb, Cd, and Cu) by adults through consumption of crops from Asopos, for an average consumption pattern, generally is well below the Allowable Daily Intakes (ADIs). Comparison was also made with data from literature from Greece.

준 실시간 측정시스템을 이용한 미세입자 원소성분 배출특성 조사

Fine particulate matter was collected as a slurry using the Semicontinuous Elements in Aerosol Sampler with time resolution of 30-min between May 23 and 27, 2002 at the Sydney Supersite, Florida, USA. Concentrations of 11 elements, i.e., Al, As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Se, and Zn, in the collected slurry samples were determined off-line by simultaneous multi-element graphite furnace atomic absorption spectrometry. Temporal profiles of and elemental concentrations combined with meteorological parameters such as wind direction and wind speed indicate that some transient events in their concentrations are highly correlated with the periods when the plume from an animal feed supplement processing facility influenced the Sydney sampling site. The peaking concentrations of the elemental species during the transient events varied clearly as the plume intensity varied, but the relative concentrations for As, Cr, Pb, and Zn with respect to Cd showed almost consistent values. During the transient events, metal concentrations increased by factors of >10~100 due to the influence of consistent plumes from an individual stationary source. Also the multi-variate air dispersion receptor model, which was previously developed by Park et al. (2005), was applied to ambient and 8 elements (Al, As, Cd, Cr, Cu, Fe, Pb, and Zn) measurements between 20:00 May 23 and 09:30 May 24 when winds blew from between 70 and , in which animal feed processing plant is situated, to determine emission and ambient source contributions rates of and elements from one animal feed processing plant. Agreement between observed and predicted concentrations was excellent (R of 0.99; and their ratio, ) when one emission source was used in the model. Average ratios of observed and predicted concentrations for As, Cd, Cr, Pb, and Zn varied from for Pb to for Cd.

Direct sample introduction of wines in graphite furnace atomic absorption spectrometry for the simultaneous determination of arsenic, cadmium, copper and lead content

A multi-element graphite furnace atomic absorption spectrometry (GFAAS) method was elaborated for the simultaneous determination of As, Cd, Cu, and Pb in wine samples of various sugar contents using the transversally heated graphite atomizer (THGA) with end-capped tubes and integrated graphite platforms (IGPs). For comparative GFAAS analyses, direct injection (i.e., dispensing the sample onto the IGP) and digestion-based (i.e., adding oxidizing agents, such as HNO 3 and/or H 2O 2 to the sample solutions) methods were optimized with the application of chemical modifiers. The mixture of 5 μg Pd (applied as nitrate) plus 3 μg Mg(NO 3) 2 chemical modifier was proven to be optimal for the present set of analytes and matrix, it allowing the optimal 600 °C pyrolysis and 2200 °C atomization temperatures, respectively. The IGP of the THGA was pre-heated at 70 °C to prevent the sputtering and/or foaming of sample solutions with a high organic content, dispensed together with the modifier solution, which method also improved the reproducibility of the determinations. With the digestion-based method, the recovery ranged between 87 and 122%, while with the direct injection method it was between 96 and 102% for Cd, Cu, and Pb, whereas a lower, compromise recovery of 45–85% was realized for As. The detection limits (LODs) were found to be 5.0, 0.03, 1.2, and 0.8 μg l −1 for As, Cd, Cu, and Pb, respectively. The characteristic mass ( m 0) data were 24 pg As, 1.3 pg Cd, 13 pg Cu, and 35 pg Pb. The upper limits of the linear calibration range were 100, 2, 100, and 200 μg l −1 for As, Cd, Cu, and Pb, respectively. The precisions were not worse than 4.8, 3.1, 3.7, and 2.3% for As, Cd, Cu, and Pb, respectively. For arsenic, a higher amount of the modifier (e.g., 20 μg Pd plus 12 μg Mg(NO 3) 2) could be recommended to overcome the interference from the presence of sulphate and phosphate in wines. Although this method increased the sensitivity for As ( m 0 = 20 pg), it also enhanced the background noise, thus only a slight improvement in the LOD of As (3.9 μg l −1) was realized. For the 35 red and white wine samples studied, the highest metal contents were observed for Cu ranging from 20 to 640 μg l −1 (average: 148 μg l −1), followed by Pb from 6 to 90 μg l −1 (average: 32.3 μg l −1), and Cd from 0.05 to 16.5 μg l −1 (average: 1.06 μg l −1), whereas the As content was below the LOD. This wide fluctuation in the trace metal content could be associated with the origin of wines from various regions (i.e., different trace metal level and/or quality of soil, and/or anthropogenic impact), and with diverse materials (e.g., additives and containers) involved in the wine production processes. The Cu content of wine samples was significantly correlated with Pb, whereas its weak anti-correlation was found with Cd. Interestingly, the level of Pb was anti-correlated with the year of production of the wines. This is likely due to the gradual decrease in the Pb content of soils of vineyards by time, which certainly causes less Pb-uptake of the grape plant, thus a decrease in the Pb content of wines as well.

Study on the simultaneous determination of some essential and toxic trace elements in honey by multi-element graphite furnace atomic absorption spectrometry

A multi-element graphite furnace atomic absorption spectrometry (GFAAS) method was elaborated and applied for the simultaneous determination of As, Cd, Cr, Cu, and Pb in various kinds of honey samples (acacia, floral, linden, rape, and milkweed) using the transversally heated graphite atomiser (THGA) with end-capped tubes and integrated graphite platforms (IGPs). For comparative GFAAS analysis, direct (without digestion) and indirect (with digestion in a microwave oven) sample preparation procedures were tested. The effects of several chemical modifiers, such as NH 4H 2PO 4, NH 4H 2PO 4–Mg(NO 3) 2, and Pd(NO 3) 2–Mg(NO 3) 2, were studied to obtain optimal pyrolysis and atomization conditions for the set of analytes studied. The most efficient modifier was proved to be the mixture of 5 μg Pd (applied as nitrate) plus 3 μg Mg(NO 3) 2, allowing the optimal 600 °C pyrolysis and 2300 °C atomization temperatures. To prevent the sputtering and foaming of the matrix during the drying and pyrolysis steps of the furnace heating program, the sample and modifier solutions (20 + 5 μl, respectively) were dispensed together onto the IGP of the THGA pre-heated at 80 °C. The effect of increasing concentration of honey matrix was studied on the integrated absorbance ( A int) signals of analytes. The A int signals of Cr and Pb were not altered up to 10% (m/v) matrix content in the sample solutions. The matrix effect was slightly suppressive on the A int signals of As, Cd, and Cu above 2% (m/v) honey concentration. The recovery was found to be ranged between 85 and 115% for Cd, Cr, Cu, and Pb, whereas it was a lower, compromise value of 70–99% for As. The limit of detection (LOD) data were 1, 0.04, 0.09, 0.3, and 0.6 μg l −1 for As, Cd, Cr, Cu, and Pb, respectively, which values correspond to 20, 0.8, 1.8, 5.3, and 12 ng g −1, respectively, in the solid samples. The characteristic masses were found to be 21 pg As, 1.3 pg Cd, 4 pg Cr, 12 pg Cu, and 33 pg Pb. The As, Cd, Cr, Cu, and Pb contents of the studied 42 honey samples varied significantly, i.e. from below the LOD up to 13, 3.3, 109, 445, and 163 ng g −1, respectively.

Elemental Analysis of Sub-Hourly Ambient Aerosol Collections

Simultaneous multielement graphite furnace atomic absorption spectrometry was used to determine Al, As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Sb, Se, and Zn in ambient air sampled at 170 L·min−1 for 30 min and collected as a slurry after dynamic preconcentration. In PM20 samples collected at College Park, MD, results were > 2σ above system blank in > 95% of samples for Al, Cd, Cu, Cr, Fe, Mn, Pb, and Zn, and > 2σ above system blank in > 80% of samples for As, Ni, and Se. Analyses of slurries of NIST SRM 1648, Urban Particulate Matter, were typically within 10% of expected values for all elements except Al, Cr, and Fe, elements for which deviations were mostly due to difficulties in transferring large particles. This problem will be reduced for urban fine particulate matter samples (PM2.5). Trends in the concentrations of elemental source markers were readily correlated with wind direction and other meteorological factors to identify the influences of local industrial emissions, including motor vehicle traffic, coal...

Direct and simultaneous determination of arsenic, manganese, cobalt and nickel in urine with a multielement graphite furnace atomic absorption spectrometer

A simple method was developed for the direct and simultaneous determination of arsenic (As), manganese (Mn), cobalt (Co), and nickel (Ni) in urine by a multi-element graphite furnace atomic absorption spectrometer (Perkin–Elmer SIMAA 6000) equipped with the transversely heated graphite atomizer and longitudinal Zeeman-effect background correction. Pd was used as the chemical modifier along with either the internal furnace gas or a internal furnace gas containing hydrogen and a double stage pyrolysis process. A standard reference material (SRM) of Seronorm™ Trace Elements in urine was used to confirm the accuracy of the method. The optimum conditions for the analysis of urine samples are pyrolysis at 1350 °C (using 5% H 2 v/v in Ar as the inter furnace gas during the first pyrolysis stage and pure Ar during the second pyrolysis stage) and atomization at 2100 °C. The use of Ar and matrix-free standards resulted in concentrations for all the analytes within 85% (As) to 110% (Ni) of the certified values. The recovery for As was improved when mixture of 5% H 2 and 95% Ar (v/v) internal furnace gas was applied during the first step of a two-stage pyrolysis at 1350 °C, and the found values of the analytes were within 91–110% of the certified value. The recoveries for real urine samples were in the range 88–95% for these four elements. The detection limits were 0.78 μg l −1 for As, 0.054 μg l −1 for Mn, 0.22 μg l −1 for Co, and 0.35 μg l −1 for Ni. The upper limits of the linear calibration curve are 60 μg l −1 (As); 12 μg l −1 (Mn); 12 μg l −1 (Co) and 25 μg l −1 (Ni), respectively. The relative standard deviations (R.S.D.s) for the analysis of SRM were 2% or less. The R.S.D.s of a real urine sample are 1.6% (As), 6.3% (Mn), 7.0% (Ni) and 8.0% (Co), respectively.

Simultaneous determination of manganese, iron and cobalt in copper with a multi-element graphite furnace atomic absorption spectrometer

A simple method was developed for the determination of trace metals (Mn, Fe and Co) in copper simultaneously using a multi-element graphite furnace atomic absorption spectrometer (Perkin-Elmer SIMAA6000) equipped with a transversely heated graphite atomizer. Copper was dissolved in nitric acid before analysis using a microwave digestion system. Pd(NO 3) 2 with the special gas (5% H 2 in Ar) was used as the chemical modifier. The accuracy of the method was confirmed by the analysis of certified reference copper (CRM#075). The interferences were removed effectively, so that a calibration curve method based on simple aqueous standards could be used. The analyzed values were in the range of 96.6% (Mn) to 113% (Co) of the certified values. The relative standard deviations for the simultaneous determination of Mn (6.5 μg/l), Fe(18 μg/l) and Co(5 μg/l) in solution from copper are 2.4–3.5% and the detection limits were 0.17 μg/g for Mn, 0.50 μg/g for Fe and 0.30 μg/g for Co.

Direct and simultaneous determination of copper, chromium, aluminum, and manganese in urine with a multielement graphite furnace atomic absorption spectrometer.

A simple method was developed for the direct and simultaneous determination of copper, chromium, aluminum, and manganese in urine using a multielement GFAAS (Perkin-Elmer SIMAA6000). Pd was used as the chemical modifier along with a special purge gas (5% H2 in Ar). A simple calibration curve method can be used (with 1:1 dilution). A standard reference material (Seronorm Trace Elements Urine) was used to find the optimal temperature program and to confirm the accuracy of the technique. The analyzed values were within 90-110% of the certified values. The relative standard deviations were 1.7, 1.5, 1.6, and 1.5% for these four elements and the detection limits were 0.08 microg L(-1) for Cu, 0.05 microg L(-1) for Cr, 0.06 microg L(-1) for Al, and 0.06 microg L(-1) for Mn. The recoveries of Cu, Cr, Al, and Mn from real urine samples were 100 +/- 5%, except for Cu (80%). The found values of Cu, Cr, Al, and Mn in a real urine sample were 14.3, 0.78, 18.9, and 0.06 microg L(-1), respectively. Scanning electron micrographs were used to investigate the physical form of Pd on the surface of the platform in the graphite furnace. Use of 5% H2 in Ar as the purge gas resulted in smaller and more uniformly distributed Pd particles (Pd particle diameters 0.4-0.6 microm using 5% H2 in Ar compared to 0.4-1.2 microm using pure Ar), increasing the effect of the Pd chemical modifier and promoting the efficiency of atomization.

Determination of chromium, molybdenum and vanadium dopants in bismuth tellurite optical crystals by multi-element graphite furnace atomic absorption spectrometry

The graphite furnace atomic absorption spectrometry (GFAAS) method were developed for the determination of chromium, molybdenum and vanadium dopants in a bismuth tellurite (Bi 2TeO 5) matrix, using a transversely heated graphite atomizer with longitudinal Zeeman background correction system. The bismuth tellurite matrix dissolved in HCl and modified by the addition of triammonium citrate (TAC) was found to be significantly more volatile than the analytes considered in the present analysis. Therefore, the matrix constituents could be removed by a selective vaporization during the pyrolysis step. By applying multiple sample dispension (5×20 μl) and pre-vaporization of the matrix, the calibration could be performed using simple, matrix-free standard solutions. Under mini-flow conditions (50 cm 3 min −1), the simultaneous GFAAS determinations of Cr, Mo and V in Bi 2TeO 5 crystals (single injection) are characterized by the limit of detection (LOD) values of 0.83, 3.9 and 4.7 μg l −1, respectively, whereas in the presence of the matrix, 1.14, 4.9 and 6.7 μg l −1 are found, respectively. The latter LOD data correspond to 0.18, 0.78 and 1.1 μg g −1 Cr, Mo and V, respectively, in the solid samples. The calibration curves of Cr, Mo and V are linear up to 40, 100 and 400 μg l −1, respectively. The characteristic masses are 7.5 pg Cr, 20 pg Mo and 58 pg V. For the multiple dosing and matrix pre-vaporization method, the LOD data of Cr, Mo and V are 0.16, 0.74 and 0.9 μg l −1, respectively, which correspond to 0.026, 0.12 and 0.14 μg g −1 Cr, Mo and V, respectively, in the solid samples.

On the Implementation of Multielement Continuum Source Graphite Furnace Atomic Absorption Spectrometry Utilizing an Echelle/CID Detection System

A continuum source, multielement graphite furnace atomic absorption spectrometer was developed that employed a high-resolution echelle polychromator with charge-injection device (CID) detection. The detection system employed a new device, the CID 38, and camera control unit, the SCM5000E, providing unique new capabilities. A data acquisition and analysis scheme was developed for the prototype system, and the instrument demonstrated detection limits approaching that of commercial line source graphite furnace atomic absorption spectroscopy (GFAAS). However, the performance degrades in the ultraviolet due to decreasing source output.

Concentrations of some elements in and on Scots pine needles

Elemental concentrations in needles from individual Scots pine trees (Pinus sylvestris L.) from four different sites in Latvia were determined. P, S, K, Ca, Mn, Fe, Cu, Zn, Rb and Sr were simultaneously determined by total-reflection x-ray fluorescence and Cr, Co, Ni, Cd, Pb were measured using multi-element graphite furnace atomic absorption spectrometry. The elemental concentrations obtained after washing the pine needles with water and with chloroform were compared with those obtained without washing. Chloroform was a more effective washing agent for the removal of airborne deposits from the surface of the needles. The comparison of the chemical compositions of pine needles that were unwashed or washed with chloroform allowed the trace elements in and on the needles to be distinguished for an evaluation of the character of pollution. Copyright © 1999 John Wiley & Sons, Ltd.

Direct and simultaneous determination of copper and manganese in seawater with a multielement graphite furnace atomic absorption spectrometer

The direct and simultaneous determinations of Cu and Mn in seawater using a multielement graphite furnace atomic absorption spectrometer (Perkin-Elmer SIMAA6000) are described. Three kinds of chemical modifier (Mg(NO 3) 2, Pd(NO 3) 2 and a mixture of these) were tested. The matrix interferences were removed completely so that a simple calibration curve method could be used to determine Cu and Mn in seawater from the open ocean using Pd or a mixture of Pd and Mg as the chemical modifier. The relative standard deviations (RSDs) for the simultaneous determination of Cu and Mn in seawater from open ocean are 10% or less, and the detection limits were 0.07 μg 1 −1 for Cu and 0.10 μg 1 −1 for Mn, using Pd as the chemical modifier. The accuracy of the method is confirmed by analysis of four kinds of certified reference saline waters.

Direct determination of traces of Ag, Cd, Pb, Bi, Cr, Mn, Co, Ni, Li, Be, Cu and Sb in environmental waters and geological materials by simultaneous multi-element graphite furnace atomic absorption spectrometry with Zeeman-effect background correction

A method was developed for direct determination of minor and trace amounts of Cr, Mn, Cu, Ni, Co, Li, Pb, Cd, Bi, Sb, Be and Ag in silicate rock, lake and stream sediments using a microwave oven dissolution method and a multi-element graphite furnace atomic absorption spectrometer equipped with a Zeeman-effect background correction device. The measurement technique was also suitable for direct determination of trace and ultra-trace amounts of these elements in drinking and seawater samples. A rock or sediment sample was brought into solution in a Teflon vessel by heating in a microwave oven with a mixture of hydrofluoric acid and aqua regia, followed by a further heating with a mixture of boric acid and ethylenediaminetetraacetic acid. The specified elements were directly determined in a group of four elements in one firing and eight elements in two firings from this solution or from a diluted solution using the optimum operating parameters developed in this work. The method, tested with 23 international reference rocks and sediments and seven international quality control and reference water samples, showed good to excellent agreement with the recommended values.

Determination of noble metals in silicate rocks, ores and metallurgical samples by simultaneous multi-element graphite furnace atomic absorption spectrometry with Zeeman background correction

A new method has been developed for rapid determination of μg/g and ng/g amounts of noble metals in silicate rocks, ores and metallurgical samples by attacking with hydrofluoric acid and aqua regia, preconcentration by ion-exchange chromatography and measuring in a simultaneous multi-element graphite furnace atomic absorption spectrometer equipped with a polarized Zeeman background correction device which eliminated interferences from any incompletely separated common elements. The method was tested for Ru, Rh, Pt, Ir, Pd, Ag and Au with three Canadian certified reference materials, and then applied to the determination of ng/g amounts of these elements in four new Canadian candidate reference materials.

Determination of scandium, yttrium and eight rare earth elements in silicate rocks and six new geological reference materials by simultaneous multi-element electrothermal atomic absorption spectrometry with Zeeman-effect background correction

A method was developed for the simultaneous determination of a group of four rare earth elements (REE) in one firing using a multi-element graphite furnace atomic absorption spectrometer. The instrument can be programmed for automatic determination of an additional four REE elements in a second group by two firings. The sensitivities with a pyrolytic graphite coated graphite tube furnace are sufficiently high to permit the determination of low-µg g–1 amounts of Y, Nd and Sm and ng g–1 amounts of Sc, Eu, Dy, Ho, Er, Tm and Yb in silicate rocks from as little as 0.1 g or less of sample concentrate in a 1 ml final volume. After dissolution of the sample in acids, Sc, Y and the REE were preconcentrated by cation-exchange chromatography or coprecipitation with calcium oxalate and hydrated iron oxide carriers and determined by the proposed method. The interferences due to the presence of trace amounts of common metals in the ion-exchange concentrates were corrected for with Zeeman-effect background correction. Inter-method correlation plots for electrothermal atomic absorption spectrometry (ETAAS)versus inductively-coupled plasma mass spectrometry (ICP-MS) values and for oxalate versus ion-exchange recovery results for REE showed good agreement. Satisfactory results were obtained for Sc, Y and eight REE in three international reference rocks, MRG-1, SY-2 and NIM-G. The method was applied to the determination of these elements in six new candidate reference rocks of the Canadian Certified Reference Materials Project. In most instances the ETAAS results compared satisfactorily with those obtained independently by inductively coupled plasma atomic emission spectrometry (ICP-AES) and ICP-MS.

Slurry sample preparation for simultaneous multi-element graphite furnace atomic absorption spectrometry

Simultaneous multi-element graphite furnace atomic absorption spectrometric analysis of solids prepared as slurries is investigated. Slurries were prepared using 5–10 mg of sample and 5 ml of dilute nitric acid. Analyses were performed on a simultaneous multi-element atomic absorption spectrometer with a continuum source (SIMAAC) using platform atomisation, integrated absorbance measurements, 20-µl sample volumes and calibration standards prepared in 5% HNO3. As many as seven elements were determined simultaneously in a total of ten different National Bureau of Standards (NBS) reference materials representing a wide variety of sample matrices. Ultrasonic agitation of the slurry preparations proved useful in avoiding setting of the particles. Typically, average accuracies of 100 ± 12% were observed.