Determination of Trace Elements in Dendrobium Officinale Cultivated in Various Conditions

Dendrobium officinale is an important medicinal plant in traditional Chinese medicine. The consumption of D. officinale has increased rapidly in recent years due to the health awareness among Chinese people. The present study aimed to determine trace elements levels in 42 D. officinale samples and to utilize the elemental data for identifying the cultivation technique. Eighteen trace elements (B, V, Cr, As, Mn, Fe, Mo, Cu, Zn, Se, Sr, Sn, Ti, Al, Co, As Pb, Cd, and Bi) were determined by inductively coupled plasma–mass spectrometry. Of the 11 essential elements, the mean concentrations ranged from 30.6?µg?kg^?1 (Mo) in D. officinale with greenhouse cultivation to 161?mg?kg^?1 (Fe) in D. officinale with rock cultivation, and the contributions of Mn may exceed the dietary reference intake value by the uptake of 20?g of D. officinale. Of the seven toxic elements, the mean concentrations ranged from 3.29?µg?kg^?1 (Bi) in the D. officinale with greenhouse cultivation to 342?mg?kg^?1 (Al) in the D. officinale with rock cultivation, and the contributions of Al may exceed the provisional tolerable daily intake value by the uptake of 20?g of D. officinale. The concentrations of seven metals (Bi, Pb, Fe, Al, Cr, As, and Mo) were utilized to identify the cultivation technique of the analyzed D. officinale samples through linear discriminant analysis.     

Direct multielement determination of trace elements in boron carbide powders by direct current arc atomic emission spectrometry using a CCD spectrometer

The use of direct current arc atomic emission spectrometry (DC-arc-AES) with a CCD spectrometer for the direct determination of the trace impurities Al, Ca, Cr, Cu, Fe, Mg, Mn, Na, Ni, Si, Ti, and Zr in three well characterized boron carbide powders is described. The detection limits obtained by the procedure were found to be between 0.2 (Mg) and 25 (Na) ??g?g^?1 for the above elements. Three boron carbide powder samples with trace element concentrations between 0.9 (Cu) and 934 (Si) ??g?g^?1 for Al, Ca, Cr, Cu, Fe, Mg, Mn, Na, Ni, Si, Ti, and Zr ?? including the standard reference material ERM?-ED102 ?? were analyzed by DC-arc-AES. The relative standard deviations for 9 measurements when using 5.0?±?0.3?mg of the respective samples were found to vary from 6.2 to 27% for Al and Cu, respectively. The trace elements Al, Ca, Cr, Cu, Fe, Mn, Ni, Si, Ti and Zr could be determined in the standard reference material and their concentrations determined by DC-arc AES were found to be between 89 and 116% of the accepted values. Fe and Ti were determined by DC-arc AES in the three boron carbide samples as well as in Al₂O₃, BN, SiC, coal fly ash, graphite and obsidian rock. The correlation coefficients of the plots of the net intensities versus the accepted values over the concentration ranges from 18 to 1750 and from 6 to 8000???g?g^?1 are 0.999 and 0.990 for Fe and Ti, respectively.

Ultrasonic dissolution for ICP-MS determination of trace elements in lightly loaded airborne PM filters

A simple single-step ultrasonic dissolution procedure for low mass (<1?mg) particulate matter (PM) filter samples using HNO₃–HF acid solution is proposed for multi-element determination using ICP-MS. The PM-loaded PTFE filter samples are inserted directly into disposable centrifuge tubes for acid extraction using ultrasonic digestion (UD). Potential interferences owing to contamination and element loss are minimized. Key factors influencing element recoveries are investigated, including digestion solution composition, acid concentration, temperature, and matrix interferences. Optimized conditions for UD include an acid mixture consisting of 4.0?mL HNO₃ and 0.1?mL HF with ultrasonication proceeding at 90°C for one hour, followed by 10-fold dilution. Recoveries of 80–120% are achieved for almost all of the 20 elements tested (Be, Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Sr, Mo, Ag, Cd, Sb, Ba, Pb and U) in four standard reference materials with contrasting matrices: NIST 1648 (urban PM), NIST 2584 (indoor dust), NIST 2710 (soil), and NIST 1633b (coal fly ash). The exception is Cr in NIST 1648 for which recovery is low (30%) using this method. Element concentrations obtained for PM-loaded filter samples using the proposed UD?+?ICP-MS method agree with results obtained using energy dispersive X-ray fluorescence (paired t-test p?>?0.2; 95% CI).     

Trace Elements in Pleurotus Ostreatus,P. Eryngii,and P. Nebrodensis Mushrooms Cultivated on Various Agricultural By-Products

Abstract

Mushrooms are efficient accumulators of essential and toxic elements. Although oyster (Pleurotus spp.) mushrooms are widely commercialized and consumed, few data exist regarding trace elements content and bioaccumulation in cultivated P. ostreatus and P. eryngii, while no data are available for P. nebrodensis. The contents of Al, As, Ba, Cd, Co, Cr, Cs, Cu, Fe, K, Mn, Na, Ni, Pb, Rb, Sr, V, and Zn were monitored using inductively coupled plasma-mass spectrometry (ICP-MS) and atomic emission spectrometry (AES) in P. ostreatus, P. eryngii, and P. nebrodensis mushrooms and their cultivation substrates that include wheat straw (WHS), grape marc (GMC), olive leaves (OLV), and two-phase olive mill wastes (OMW), separately or in mixtures. Bioaccumulation factors (BAFs) less than 0.3 were obtained for Al, Ba, Co, Cr, Fe, Mn, Ni, Pb, Sr, and V; BAFs exceeding 1 for K?>?Zn?>?Cd?>?Cr?>?Rb?>?As, while the BAFs for Na were less 0.7. Mushrooms grown on OLV and OMW presented lower BAFs than those grown on WHS and GMC for all elements except for K, Cd, and Cu. P. ostreatus was an effective accumulator for Cr, Fe, and Zn; P. eryngii for Al, Cs, Ni, and V; and P. nebrodensis for As and Cd. The estimated daily intakes (μg kg^?1 body weight) from mushroom consumption were less than 0.010 for As, Cd, Co, Cs, Pb, and V, 0.010–0.10 for Ba, Cr, Ni, and Sr, 0.10–5.0 for Al, Cu, Fe, Mn, Rb, and Zn, 65–83 for Na, and 858–1030 for K. Overall, the mushrooms studied provide significant amounts of K, adequate amounts of Mn and Zn and low amounts of Na and toxic elements.     

A new approach for determination of crustal and trace elements in airborne particulate matter

An ICP-OES procedure was developed for fast and accurate determination of various crustal (Al, Ca, Fe, Mg, Si) and trace elements (Ba, Cu, Mn, Na, K, Sr, Ti, Zn) in airborne particulate matter. The method is based on a preliminary treatment of the aerosol samples with a mixture of nitric acid and hydrogen peroxide at elevated temperature leading to a mineralization of the organic sampling substrate, dissolution of soluble material and homogeneous suspension of the remaining non-soluble fraction. After dilution the derived slurry solutions were measured using ICP-OES. The reproducibility of analysis given as the relative standard deviation (% RSD) varied between 3.2 and 6.8% for bulk constituents such as Al, Ca, Fe, Mg and Si whereas values ranging from 3.5 to 9.1% were obtained for trace metals present with distinctly lower abundance in PM10 (e.g. Ba, Cu, Mn, Sr, Zn). The limits of detection (LOD) calculated as three times the standard deviation (3σ) of the signal derived from filter blank samples ranged from approximately 1?ng?m^?3 (Sr) to 71?ng?m^?3(Ca). The developed procedure was evaluated by comparing the obtained results with the findings derived for the same set of aerosol samples analyzed using a microwave procedure for sample dissolution with subsequent ICP-OES analysis. Finally the developed procedure was applied for the analysis of crustal and trace elements in PM10 samples collected at an urban site (Getreidemarkt, Vienna) and a rural site (Hartberg, Styria), in Austria. The concentrations of the investigated crustal elements varied between some hundred ng?m^?3 and few µg?m^?3 with highest concentrations for Fe and Si, distinctly reduced concentrations ranging from some ng?m^?3 (Sr) to more than hundred ng?m^?3 (K) were found for trace elements. Observed PM10 concentrations were found to be in accordance to literature findings from urban sites in central Europe.     

Trace metals in mussel shells and corresponding soft tissue samples: a validation experiment for the use of <Emphasis Type="Italic">Perna perna</Emphasis> shells in pollution monitoring

The uptake of Cr, Mn, Ni, Cu, Zn, Cd and Pb in soft tissue of Perna perna mussels and their shells has been studied in aquarium experiments in which mussels were exposed for 30 or 60 days to seawater spiked with different concentrations of these contaminants (125 and 500 μg L⁻¹). Tissue samples were analyzed after acid digestion by conventional solution nebulization ICP–MS. Laser ablation ICP–MS was used for the quantitative determination of trace elements in different areas of the corresponding shells. With the exception of Mn and Zn, all other elements studied showed a significant concentration enhancements in soft tissue, with the magnitude of this enhancement following the order: Cr > Ni > Cd > Cu > Pb. A corresponding increase in most contaminants, although less pronounced, was also observed in the newly formed growth rings of mussel shells, contributing to the validation of Perna perna mussel shell as a bioindicator of toxic elements.     

Trace elements in the scalp hair of patients with alcohol induced psychosis

A number of essential trace elements play a major role in various metabolic pathways and in many diseases like autoimmune, neurological and psychiatric. This study is undertaken with an aim to evaluate the levels of different trace elements in the scalp hair samples of patients suffering from alcohol induced psychosis by particle induced X-ray emission technique (PIXE). It is observed that Fe (p?<?0.0005), Cu (p?<?0.001) are significantly higher in the hair samples of alcohol induced psychosis patients compared to those in normals while concentrations of Mn (p?<?0.005) and Zn (p?<?0.0001) are lower. The concentrations of Co and Ni in the hair samples are found to be in consonance with the concentrations in the normals.     

Determination of minor, trace and toxic elements in chewing tobacco products by instrumental neutron activation analysis and identification of glutamic acid

Tobacco smoking/chewing has been a cause of concern because of it being related with oral cancer. It causes stimulation and ill physiological effects. Ten different brands of spit tobacco, eight gutkaas and five paan masalas have been analyzed for seven minor (Al, Na, K, Ca, Cl, Mg, and P) and 17 trace (As, Ba, Br, Co, Cr, Cs, Cu, Eu, Fe, Hg, La, Mn, Rb, Sb, Sc, Th, and Zn) elements by instrumental neutron activation analysis. Also Ni and Pb were determined by atomic absorption spectrophotometry. Concentration of Cd was below detection limit (<10?mg?kg^?1) in the tobacco samples. Mg, generally added as MgCO₃ to prevent caking, is present as minor constituent in spit tobacco and gutkaas but is below detection limit (<1?g?kg^?1) in paan masalas. Most elemental concentrations vary in a wide range depending on the nature of chewing tobacco. Spit tobacco has been found to be more enriched in essential elements (Ca, K, Na, P, Mn, and Rb), whereas gutkaas contain higher concentrations of Fe, Cr, Cu, and Zn. Paan masalas contain lower contents of other elements but higher content of Hg. Gutkaas also contain higher amounts of As and Pb. Further glutamic acid has been separated from tobacco leaves and characterized as it might bind with some elements.     

Continuous sonoassisted digestion coupled to flow injection minicolumn separation for the determination of total and labile Cu and Fe in fresh waters by flame atomic absorption spectrometry

An automatic on-line system is developed for the trace determination of copper and iron species in fresh waters by flame atomic absorption spectrometry using only 5 and 2?mL of sample, for copper and iron determination, respectively. This system, which includes a home-made minicolumn of commercially available resin containing aminomethylphosphonic acid functional groups (Chelite P), comprises two operational modes. The first, used for the determination of the dissolved labile fraction (free copper and iron ions and their weak complexes) is based on the elution of this fraction from a minicolumn containing the chelating resin loaded in-situ with the sample. The second mode is used for the determination of total trace copper and iron concentrations. This last mode is based on the retention/preconcentration of total metals on the Chelite P resin after on-line sonoassisted digestion of water samples acidified with nitric acid (0.5?mol?L^?1 final concentration) to break down metal organic complexes present in fresh waters as river waters. The figures of merit for copper and iron determination in both fractions are given and the obtained values are discussed. The analytical method was characterized and the limit of detection and limit of quantification for the two metals were 0.5 and 1.6?µg?L^?1 for Cu and 2.3 and 6.1?µg?L^?1 for Fe, respectively. The repeatability, expressed as relative standard deviation, was in the range 1.0–2.1%. The speciation scheme was applied to the analysis of river surface water samples collected in Galicia (Northwest, Spain).     

Pulverized Banana Peel as an Economical Sorbent for the Preconcentration of Metals

A procedure for the determination of trace levels of Cd, Co, Cr, Fe, Mn, Ni, and Pb by flame atomic absorption spectrometry using a column preconcentration system is described in which the metals were adsorbed on pulverized banana peel, an economically and environmentally acceptable sorbent. In the optimization procedure, five variables (sample pH, mass of biosorbent, type of eluent, sample flow rate, and volume) were optimized and the capacity of the biosorbent was established. Under the optimized conditions, the detection limits of the method were 2.4, 27.0, 49.4, 31.1, 6.7, 29.6, and 46.2 µg L^?1 for Cd, Co, Cr, Fe, Mn, Ni, and Pb, respectively. The precision, expressed as relative standard deviation, was less than 4% based on twelve measurements. The recoveries were 81.1% (Cd), 91.4% (Co), 87.2% (Cr), 90.1% (Fe), 88.0% (Mn), 94.1% (Ni), and 93.2% (Pb) under the optimum conditions (pH; 9, sample flow rate; 3 mL min^?1, mass of biosorbent; 200 mg; eluent; 1 mol L^?1 nitric acid, preconcentration factor; 10). The sorption capacity of pulverized banana peel was 15.12, 28.85, 32.70, 30.44, 30.94, 28.97, and 8.21 µmol per gram of adsorbent for Cd, Co, Cr, Fe, Mn, Ni, and Pb, respectively.     

Stripping voltammetry method for determination of manganese as complex with oxine at the carbon paste electrode with and without modification with montmorillonite clay

Oxine (8-hydroxyquinoline) was used as an efficient and selective ligand for stripping voltammetry trace determination of Mn(II). A validated square-wave adsorptive cathodic stripping voltammetry method has been developed for determination of Mn(II) selectively as oxine complex using both the bare carbon paste electrode (CPE) and the modified CPE with 7 % (w/w) montmorillonite-Na clay. Modification of carbon paste with montmorillonite clay was found to greatly enhance its adsorption capacity. Limits of detection of 45 ng l^?1 (8.19?×?10^?10 mol L^?1) and 1.8 ng l^?1 (3.28?×?10^?11 mol L^?1) Mn(II) were achieved using the bare and modified CP electrodes, respectively. The achieved limits of detection of Mn(II) as oxine complex using the modified CPE are much sensitive than the detection limits obtained by most of the reported electrochemical methods. The developed stripping voltammetry method using both electrodes was successfully applied for trace determination of Mn(II) in various water samples without interferences from various organic and inorganic species.     

微波消解和电感耦合等离子体发射光谱法同时测定煤灰中的14种元素

应用微波消解和电感耦合等离子体发射光谱法同时测定煤灰中的常量、少量和微量元素Si、Al、Ca、Fe、Mg、Ti、K、Ba、Mn、V、Pb、Cr、Cu和Zn。考察了微波消解体系和消解条件，0．1g煤灰用10mL硝酸和1mL氢氟酸分解，加入10mL4％硼酸溶液分解氟化物沉淀。用本法测定煤飞灰标准参考物质的结果与标准值一致。方法准确，快速，回收率为94．2％～102．3％；RSD均小于5％。     

Indirect Determination of Sulfide by Extraction Flotation Spectrophotometry of Copper(II) with Ammonium Sulfate‐Ethanol‐Water System

A new extraction flotation spectrum method for indirect determination of trace amounts of sulfide by ammonium sulfate‐ethanol‐water system was developed. It showed that Cu(II) could combine with S^2? into precipitate (CuS) which was floated in the surface of ethanol and water in the presence of ammonium sulfate. The sulfide can be indirectly determined by determining the flotation yield of Cu(II). The linear range from 2.4 × 10^?8to 3.2 × 10^?6g/mL and the detect limit of 2.0 × 10^?8g/mL was achieved. The results showed the determination of S^2? was not affected by Pb(II), Zn(II), Cd(II), Fe(II), Co(II),Ni(II), Mn(II) and Cl^?, Br^?, I^?, etc. In the paper, the method was successfully applied to the determination of a trace amount of sulfide in polluted water samples with the advantages of simplicity of equipment, rapidity, low cost, etc.     

Trace metal accumulation in tissues of sole (Solea senegalensis) and the relationships with the abiotic environment

The distribution patterns and the organ-specific accumulation trends of 10 trace metals (iron, manganese, zinc, copper, chromium, nickel, cobalt, lead, cadmium and silver) and 4 major elements (sodium, potassium, calcium and magnesium) in 10 different tissues (heart, muscle, kidney, stomach, intestine, liver, gill, gonads, white skin and dark skin) of a benthic fish species (Solea senegalensis) from a densely populated coastal area affected by anthropogenic activities, the Bay of Cadiz (SW Spain), have been investigated. High variability of metal concentrations among tissues were found for Ca, Fe, Zn, Cu, Pb and Ag. Factor analysis was applied to study this variability. Five principal components were found explaining the 92.95% of the total variance and similarities in behavioural patterns of bioaccumulation were described. They associated Mg, Cr, Ni and Mn to intestine and stomach tissues (PC1), Ag, Cu and Cd to liver (PC2), Zn, K and Co to gonads (PC3), Na, Fe and Pb to gill, heart and kidney tissues (PC4) and Ca, Pb and Mn to gill and dark skin (PC5). The metallic concentration in the sediment and water was also studied. The pollution in this area was found moderate with outstanding values of Zn, Cu and Pb (average values of 139, 50.4 and 75.6?mg?kg^?1, respectively) in sediment and dissolved Cu (average value of 2.5?µg?L^?1). Metal bioconcentration trends followed the order Zn?>?Cu?>?Cd?>?Pb for dissolved metals in seawater, Cu?>?Zn?>?Cd?>?Pb?≈?Mn?>?Fe?≈?Ni?≈?Co for metals associated to particulate matter and Zn?≈?Cu?>?Cd?>?Mn?>?Co?≈?Fe?>?Ni?≈?Pb?>?Cr for metals in the sediment. Higher values were found for copper in liver, zinc in gonads and lead in gill, showing the relationship between biotic and abiotic environment. In addition, Cd bioconcentration factors were found high in liver and gill showing the sensitivity of sole to this metal even at low concentrations.     

Trace Determination of Germanium by Continuous Flow Hydride Generation Laser-Induced Fluorescence Spectrometry

A continuous flow hydride generation laser-induced fluorescence (HG-LIF) spectrometry technique has been investigated for performing trace determination of germanium (Ge). Hydride generation of Ge is performed using reagent concentrations of 2?M H₃PO₄ and 0.5% NaBH₄ and fluorescence detection is performed using tunable dye laser radiation at 253.323?nm for Ge excitation with fluorescence measured at 303.907?nm. The HG-LIF approach provides a linear response for Ge in the concentration range from 1.0 to 50?ng mL^?1 and a limit of detection of 0.1?ng mL^?1. Replicate measurements at 10?ng mL^?1 have a relative standard deviation of 0.1% (n?=?8). Measurements of Ge in different sample matrices have demonstrated the effectiveness of thiourea and ascorbic acid as masking agents that compensate for samples containing interfering ions. The determinations of the Ge content in reference water samples, fly ash samples, and supplement capsules demonstrate that the HG-LIF approach has feasibility for measuring Ge in different sample matrices at environmentally relevant concentrations.     

Trace metal analysis of coal fly ash collected plain and on a quartz fibre filter

A simple, uniform procedure has been developed for microwave-based digestion of fly ash samples collected from the hoppers of an electrostatic precipitator (ESP), or collected from flue gases on a heat-resistant quartz fibre filter and for subsequent atomic absorption spectrometric analysis of trace metals (Be, Cd, Co, Cr, Cu, Mn, Ni, Pb, V and Zn). HNO₃, HCl, HF and mixtures have been tested as digestion acids. The combination of HNO₃ and HF has been found to be efficient for the digestion of fly ash samples with and without quartz fibre filter material. In spite of the complicated matrix, results with satisfactory accuracy and precision (relative standard deviation below 10% for most of the elements) have been obtained. In the case of analysis of fly ash together with a quartz fibre filter, the calibration curve has to be determined by standard addition to a blank solution containing a dissolved blank quartz fibre filter.     

Determination of traces of As,Cd, Cr,Hg, Mn,Ni, Sb,Se, Sn and Pb in human hair by triple quadrupole ICP-MS

With the wide range of metallic contaminants discharged in the environment, studying the human health requires a growing number of elements to be monitored in biological samples. Hair analysis has been suggested as a suitable tool for biomonitoring environmental and occupational exposure to toxic elements. This study describes a method for the determination of 10 trace elements in hair samples using ICP-QQQ-MS. Combining the power of the MS/MS high-energy Helium mode with the MS/MS O₂ mass-shift mode, the method offers great analytical performances with detection limits reaching 0.0014 µg g^?1 for As, 0.0016 µg g^?1 for Cd, 0.012 µg g^?1 for Cr, 0.0035 µg g^?1 for Hg, 0.0055 µg g^?1 for Mn, 0.10 µg g^?1 for Ni, 0.0012 µg g^?1 for Sb, 0.0083 µg g^?1 for Sn, 0.011 µg g^?1 for Se and Pb. The accuracy of the method was tested on a human hair ERM® certified reference material. Percent recoveries varied from 91.3% and 106.9% being always in the acceptance range of 90–110%. For all analysed elements, RSD% of repeatability ranged between 0.6% and 9.0% and those of intermediate precision did not exceed the limit of 20% being always lower than 10% (except for As). The proposed method was applied for the determination of trace elements in hair samples from 20 unexposed subjects. The geometric mean levels were as follows: Cr 0.28 µg g^?1, Mn 0.30 µg g^?1, Sn 1.04µg g^?1, Sb 0.07 µg g^?1, Hg 0.42 µg g^?1, As 0.02 µg g^?1, Cd 0.03 µg g^?1, Ni 0.51 µg g^?1, Se 0.45 µg g^?1 and Pb 1.83 µg g^?1. Element concentrations were in the same range with the reported data. The reported results may be useful for environmental exposure assessment or comparisons studies when establishing reference values of trace elements in exposed population.     

Verbundverfahren zur Multielement-Spurenbestimmung in hochreinem Chrom nach Spuren—Matrix-Trennung

(Simultaneous determination of trace elements in high-purity chromium by inductively-coupled plasma/atomic emission spectrometry after matrix separation.) The production of high-purity metals requires routine determinations of elements in the ng g^?1 range. Procedures based on wet chemical separation of matrix and trace elements followed by inductively-coupled plasma/atomic emission spectrometry are suitable. The separation of 19 trace metals (Be, Bi, Ca, Cd, Co, Cu, Fe, La, Mg, Mn, Nb, Ni, Pb, Ta, Ti, Th, U, Zn and Zr) from high-purity chromium powder is described. The powder is dissolved in hydrochloric acid and oxidized with perchloric acid or alkaline hydrogen peroxide, and the trace elements are precipitated at pH 11–13 and collected on cellulose loaded with indium hydroxide or on cellulose-Hyphan. The detection limits of the total procedure vary from 10 ng g^?1 for cadmium to 600 ng g^?1 for zinc.     

Toxic mineral elements in Mytilus galloprovincialis from Sicilian coasts (Southern Italy)

Abstract

We assessed the relationship between V, Cr, Mn, Hg, As, Cd, Sn, Sb and Pb concentrations in Mytilus galloprovincialis samples from the coasts of Sicily and the expression of metallothioneins. Toxic mineral elements assessment was carried out by A.A. Spectrometry and ICP-MS. The metallothioneins expression was performed by q-PCR method. Low metals’ levels were found in the mussel samples examined, in comparison with what was reported in literature. The highest mean values of toxic mineral elements were found in Gela (Cr 0.178?±?0.03?mg/Kg, Mn 4.325?±?0.012?mg/Kg, As 3.706?±?0.009?mg/Kg, Sn 0.148?±?0.014?mg/Kg, Sb 0.009?±?0.004?mg/Kg e Pb 0.364?±?0.01?mg/Kg). Significant levels of Hg were found in samples from Catania (0.014?±?0.005?mg/Kg). Only vanadium and lead concentrations showed significant differences between sampling areas (p?<?0.05). Molecular analysis verified a basal expression of Mt1 and the absence of over-expression of Mt2, confirming the low mineral’s concentrations found in the samples examined.     

Application of multivariate optimization in the development of an ultrasound-assisted extraction procedure for multielemental determination in bean seeds samples using ICP OES

In this paper, multivariate optimization was applied for the development of an ultrasound-assisted multielemental extraction procedure for analysis of bean samples by inductively coupled plasma optical emission spectrometry. For this procedure, powdered samples were treated with an acid mixture and submitted to ultrasound energy for extracting the target elements (Ba, Ca, Cu, Fe, K, Mg, Mn, Sr and Zn). Centroid simplex mixture design was used for optimize the acid proportions (nitric, acetic and chloride acid) and Box Behnken design was applied for optimize the process variables (particle size, final concentration of extracting solution and sonication time) after mixture optimization. Iron had not presented quantitative extractions and it was excluded from final samples analysis. The developed method presents the follow limits of quantification in μg g^{− 1}: Ba (0.90); Ca (5.2); Cu (4.0); K (0.90); Mg (1.4); Mn (0.22); Sr (0.25) and Zn (4.0). Accuracy was accessed by comparison of determined concentration with the values obtained by the microwave digestion procedure. The proposed method was applied toward the determination of elemental composition in bean samples collected in the country zone from Jequié city located on the Bahia State, Brazil. The trace elements content ranged from 0.21 to 3.04, 3.84 to 10.8, 0.60 to 5.23, 31.0 to 46.5 and 10.8 to 19.6 μg g^{− 1} Ba, Cu, Sr, Zn, Mn, respectively. The major elements content ranged from 0.0418 to 0.0877, 0.109 to 0.153 and 1.30 to 1.56% (w/w) Ca, Mg and K, respectively.