Determination of heavy metals in air conditioner dust using FAAS and INAA

The elements Cd, Cr, Cu, Mn, Ni, Pb and Zn were determined in dust samples collected from air conditioner (AC) filters from 15 commercial sites of Lahore using flame atomic absorption spectroscopy (FAAS). The elements Cr, Mn and Zn were also determined using instrumental neutron activation analysis (INAA). The results obtained showed that higher amounts of these metals were measured in these dust samples than normally found in soil. This was especially true for Cd, Cu, Pb and Zn. Generally the amounts of Cd, Cr and Mn did not vary throughout the city of Lahore but the amounts of the traffic related Cu, Pb and Zn elements had the more variable ranges of 30–140, 30–230 and 74–2810 mg/kg respectively. The concentrations obtained for Cr, Mn and Zn by INAA were found to be higher than those obtained using FAAS. Analysis of the data obtained showed the digestion procedure employed to be the possible cause for this occurrence. It was also found that Mn was being over-estimated by INAA due to the interference from the Mg peak.     

Determination of selected elements by X-ray fluorescence spectrometry in liquid drug samples after the preconcentration with thioacetamide

Preconcentration performance characteristics of precipitation of Mn, Fe, Co, Cu, Zn, Pb, Hg, and Cd and with subsequent filtration through cellulose nitrate membrane were investigated for the X-ray spectrometry identification and determination of trace metal ions in drug samples. The method was optimised for several parameters, including pH and amount of thioacetamide. The investigated analyte ions were collected on cellulose nitrate membrane filter (Pragopor 4) as sulphides after the reaction with thioacetamide. Optimal reaction conditions were found out (pH 8.5 for Fe, Zn, Hg, and Cd and pH 11.5 for Mn, Co, Cu, and Pb; 1.2 mL of added thioacetamide). Thereafter, the content of these elements was determined in the samples of drugs—NaCl, glucose and dextrane. The rapidity of this method, its polycomponent character and low detection limits (for filters: Mn—1.09 μg, Fe—1.08 μg, Co—0.82 μg, Cu—0.42 μg, Zn—0.61 μg, Pb—0.45 μg, Hg—0.42 μg, and Cd—0.99 μg) have proved this method to be very promising in rapid screening used in quality control of drugs.     

急性脑血管病患者血清元素的测定

采用高频等离子体发射光谱法测定了３４例脑梗塞、３３例脑出血和对照组２７人血清锌、铜、锰、铬、镁、钼、锶、铁、钛、钡、镉和钙共１２种元素的含量。结果显示脑梗塞和脑出血组血清锌和锌／铜比值显著高于对照组；锰和钼含量仅在脑梗塞组明显增高，锶仅在脑出血组显著增高，而其它几种元素疾病组与对照组无显著性差异。伴有高血糖、高血脂和高血压的病人，其血铬含量显著降低，表明锌、锌／铜比值、锰、钼、锶、铬元素与急性脑血     

Simultaneous determination of copper,manganese, zinc and sodium in plant materials by neutron activation analysis

Neutron activation analysis has been used for the simultaneous determination of Cu, Mn, Zn and Na in plant materials. The heterocyclic dye PAN has been applied as a chelating agent to achieve the group chemical separation of Mn, Cu, Ni and Zn. Various factors which affect the formation and extraction of the PAN-metal chelates have been studied and optimized, using suitable aqueous solutions to selectively strip these elements from the organic phase. This procedure has been applied to the determination of these elements in ‘Bowen’s Kale’ and U.S. NBS Citrus-leaves and Tomatoleaves samples.     

Distribution coefficients for twelve elements in oxalic acid medium on a strong anion-exchange resin

The distribution coefficients were determined for twelve elements, namely As(III), Ce(III), Cr(III), Co(II), Cu(II), In(III), Lu(III), Mn(II), Hg(II), Mo(VI), Sc(III) and Zn(II), on a strong base anion exchanger in pure oxalic acid solutions. The K_D curves are given. A scheme was developed for the chromatographic separation of five elements, namely As(III), Mn(II), Co(II), Zn(II) and Cu(II). Ce(III) can be separated from Lu(III).     

Inductively Coupled Plasma Mass Spectrometry for Sequential Determination of Trace Metals in Rain and River Waters Using Electrothermal Vaporization

Abstract

The sequential determination of 14 trace metals, Al, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Mo, Cd, Sb and Pb, in rain and river water samples has been investigated using an inductively coupled plasma mass spectrometry (ICP-MS) with a graphite rod electrothermal vaporizer (ETV) in the presence of the mixed modifier of palladium nitrate and magnesium nitrate. The sensitivity enhancements due to the presence of the modifier were observed for all analyte elements. Detection limits as high as 0.52, 0.13, 0.89, 0.35, 1.76, 0.5, 0.9, 0.5, 0.04, 1.03, 0.28, 0.07, 0.1 and 3.78 pg, respectively, for Al, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Mo, Cd, Sb and Pb have been achieved. For the determination of trace metals in both rain and river water samples by this method, the repeatibility of sample solution were very good, i.e. from 1% to 7% (as a coefficient variation) and the recoveries of elements were good enough, i.e. from 81% to 106%, by using a standard addition method. There was no difference between the results obtained by nebulizer ICP-MS and those obtained by this method, except for zinc and arsenic.     

Determination of 24 elements in four algae reference materials by neutron activation analysis and inductively coupled plasma mass spectrometry

Four algae reference materials, IAEA-391, 392, 393 and IAEA-140, prepared by the International Atomic Energy Agency for intercomparison under different preparation conditions were analyzed for 24 elements. Conventional neutron activation analysis (NAA) was used to determine Al, Ca, Cl, Co, Cr, Cu, Fe, K, Mg, Mn, Mo, Na, Sb, V and Zn and epithermal NAA using BN and Cd as shielding material for I, Br, As, Ni, Mo and Cd. Inductively coupled plasma mass spectrometry (ICP-MS) as a complementary and comparative method was applied to determine Pb, Sn, Ni, Sr, Rb, As, Co, Cr, Cu, Mn, V, Mo and Zn. Two analytical quality control standard reference materials IAEA-V-10 (hay powder) and IAEA-331 (spinach) were analyzed simultaneously with real samples. The results agree quite well with each other and with the certified values.     

血清中Mo、Se、Mn、Cu、Zn与食管癌的关系探讨

通过对１８例食管癌患者以及８０例对照组血清中Ｍｏ、Ｓｅ、Ｍｎ、Ｃｕ、Ｚｎ的测定分析，发现食管瘤患者血硒含量明显低于对照组，二者之间有极显著性差异（Ｐ＜０．０１）。而血铜、铜／锌比值食管癌组明显高于对照组，差异有显著性（Ｐ＜０．０５）。Ｍｏ、Ｍｎ、Ｚｎ元素的含量在二组之间无显著性差异（Ｐ＞０．０５）．提示血清硒铜与食管癌有关。     

Trace characterisation of lithium niobate by neutron activation analysis

Summary Coprecipitation behaviour of As, Au, Co, Cr, Cu, Eu, Fe, Ir, La, Lu, Mn, Mo, Nb, Ni, Pd, Pt, Sb, Sc, Ta, W, Zn and Zr during precipitation of hydrous oxide of niobium from lithium niobate was investigated. The matrix was dissolved in HF-HNO₃, evaporated to dryness and niobium was precipitated from HNO₃-H₂O₂ medium. The recovery studies were made using radiotracers. A radiochemical separation scheme based on group precipitation has been developed for the determination of Au, Co, Cr, Cu, Fe, Mn, Ni, Pd, Pt, Zn, Zr and rare earth elements. The method was applied to the analysis of lithium niobate. This analysis has provided fruitful information for improving the quality of the crystal.     

Systematic investigation of some metal cation interferences on the determination of molybdenum by flame atomic absorption spectrometry

The interference effects of some metal cations on the absorbance of Mo during its determination by flame AAS have been investigated, in air-acetylene flame, at a fuel flow rate of 1.8 L/min. While the interfering ion concentration was changing between 5 and 40 000 mg/L, the Mo concentration was taken as 10, 20 and 40 mg/L. It was shown that even at low concentrations of interfering ion there was a large suppression of Mo absorbance. No absorbance was observed for Mo in the presence of 50 time higher concentration of Mg, Ca, Sr, and Ba. These interference effects were suppressed by additions of 0.04% (m/v) sodium diethyldithiocarbamate (Na-DDTC), 2% (m/v) ammonium chloride, and 0.4% (m/v) sodium hydrogen phosphate. The interference from another group of elements, Mn, Fe, Al, Cd, Ni, Cr, Co, Cu and Zn, has been also investigated. In the presence of above mentioned metals, except Mn, the reproducibility of Mo absorption signal was not satisfactory. In the presence of Mn (5–40000 mg/L) the absorbance of Mo decreased significantly, however, the reproducibility was high. Molybdenum absorbance decreased under the influence of 5000–40000 mg/L of Fe, Co, Ni, 500–40000 mg/L of Cr. On the other hand, the absorption signal of Mo increased at about 20–40% in the presence of Zn and Cd. By the addition of 2% NH₄Cl the interference of these metals could be eliminated completely for all mass ratios of Mn: Mo and up to Mo: M mass ratio of 1: 10–1: 100 for the other metals, and reliable absorbance signals of Mo were obtained. The text was submitted by the authors in English.     

Polarographic determination of cadmium, lead, nickel, thallium and uranium(VI) in isoquinoline formate

Summary The polarographic behaviour of Cd, Pb, Ni, Tl and U(VI) has been described in 0.1 M isoquinoline formate as base electrolyte. In all cases well defined reversible waves were obtained and determinations are possible in the presence of Mo, Co, Zn, Mn, Te, In, Se, Fe, Cr, V, Th, Zr, As, Sb, Ag, Hg and Cu.

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Polarographische Bestimmung von Cadmium, Blei, Nickel, Thallium und Uran(VI) in Isochinolinformiat

Zusammenfassung Das polarographische Verhalten von Cd, Pb, Ni, Th. und U(VI) in 0,1 M Isochinolinformiatlösung wird beschrieben, Bestimmungsmöglichkeiten werden aufgezeigt. In allen Fällen werden gut definierte reversible Stufen erhalten. Folgende Elemente stören nicht: Mo, Co, Zn, Mn, Te, In, Se, Fe, Cr, V, Th, Zr, As, Sb, Ag, Hg, Cu.

     

Comparison of nondestructive proton and neutron activation: The case of biological samples

The capabilities of reactor neutron and 12 MeV proton activation were evaluted on samples of orchard leaves, beef liver and bovine liver. Based on γ-ray spectrometry, As, Ca, Cu, Fe, Mo, Pb, Sr, Ti, Zn and Zr at levels ranging from 2 to 20 900 ppm were detected following proton activation of 1 hour. Al, Br, Ca, Cl, Cu, Mg, Mn, Rb and V (ranging from 0.4 to 20 900 ppm) were measured by neutron activation (1 min irradiation). As, Ba, Br, Cr, Co, Fe, Hg, La, Na, Rb, Sb and Zn (ranging from 0.2 to 2400 ppm) were determined following a 14 h neutron irradiation. Although covering different elements, the two techniques are comparable in their scope, i. e. detection limits that can be achieved and number of elements that can be detected simultaneously.     

Radiochemical separations for inorganic trace elements in some biological reference materials,foods, tissues and body-fluids

A simple radiochemical machine incorporating ion-exchange procedures has been described. The system has been tested repeatedly for the determination of Cd, Co, Cr, Cu, Mn and Mo at ultra trace concentration levels in a variety of biological samples such as reference materials, human blood serum, human milk, hair and certain dietary materials, thereby demonstrating its suitability for practical use. The procedure can also yield results for A, Au and W, without any further chemical manipulations. Results show <1, 0.12, 0.18, 983, 0.61 and 0.91 g/l for Cd, Co, Cr, Cu, Mn and Mo, respectively, in human blood serum. Corresponding concentrations in human milk are <1, 0.25, <1, 186 to 310, 4 to 40 and 5.8 g/l. Among the reference materials, IAEA milk standard A-11 shows 1.85, 5.1, 17, 380, 260 and 101 ng/g for Cd, Co, Cr, Cu, Mn and Mo, respectively. Corresponding concentrations in animal muscle H-4 are 4.1, 5, 10.2, 4000, 455 and 45 ng/g. Importantly, this scheme has been applied to process large number of samples from single investigations such as those arising from dietary studies, obtaining quick and reliable data for routine use.In memory of Knut Samsahl, the devoted Norwegian radiochemist.     

Comparison of analytical methods: ICP-QMS,ICP-SFMS and FF-ET-AAS for the determination of V,Mn, Ni,Cu, As,Sr, Mo,Cd and Pb in ground natural waters

Three analytical methods, namely, inductively coupled plasma sector field mass spectrometry (ICP-SFMS); inductively coupled plasma quadrupole mass spectrometry (ICP-QMS) and filter-furnace electrothermal atomic-absorption spectroscopy (FF-ET-AAS) for the determination of V, Mn, Ni, Cu, As, Sr, Mo, Cd and Pb in ground natural water samples were compared and evaluated for their capacity to provide reliable and precise results. Two certified reference materials (SLEW-3 Estuarine Water; SLRS-4 River Water) were analysed to prove that accurate results could be obtained by using all the listed methods with properly optimised parameters. The limit of detection (LOD) for V, Mn, Ni, Cu, As, Sr, Mo, Cd and Pb provided by the ICP-MS methods ranged from 0.001 to 0.05 µg L^?1. Such LOD proved sufficient for the reliable determination of the listed elements in ground natural waters. However, the LOD of the FF-ET-AAS was approximately two orders of magnitude higher than that of ICP-MS, which made it impossible to quantify V, Mn, Ni, Mo and Pb. The effects of the usage of the collision cell mode in ICP-QMS and of the desolvation system Apex for ICP-SFMS to eliminate oxide ions levels were investigated. For all three analytical methods, the influence of the matrix effect on the results of the determination of the investigated elements using matrix model solution, external calibration and standard addition methods was evaluated. A comparison using a paired Student’s t-test between the results obtained by both ICP-MS methods for V, Mn, Ni, Cu, As, Sr, Mo, Cd and Pb concentrations in ground natural waters showed that there was no significant difference on a 95% confidence level. The precision of the results for ICP-SFMS, ICP-QMS and FF-ET-AAS varied between ~0.5 and 11; 2.5 and 12.5; 3 and 13.5%, respectively. Moreover, ICP-SFMS equipped with the desolvation system APEX proved a better choice for As, Cu and Mn analysis due to its better LOD (0.008, 0.03 and 0.02 µg L^?1, respectively) and precision (S_r ≤ 5.0; 7.5; 9.0%, respectively) compared to ICP-QMS and FF-ET-AAS.     

Nanometer-sized zirconium dioxide microcolumn separation/preconcentration of trace metals and their determination by ICP-OES in environmental and biological samples

A new method is proposed using a microcolumn (20 mm × 2.0 mm) packed with nanometer-sized zirconia as solid-phase extractor for the separation/preconcentration of Mn, Cu, Cr, Zn, Ni and Co prior to their determination by inductively coupled plasma optical emission spectrometer (ICP-OES) in environmental samples. The factors affecting the separation and preconcentration of analytes such as pH, sample flow rate and volume, eluent concentration and volume were determined, interfering ions were studied, and the optimal experimental conditions were established. The adsorption capacity of nanometer-sized ZrO₂ for Mn, Cu, Cr, Zn, Ni and Co was found to be 1.3, 1.3, 1.7, 2.0, 3.9 and 1.5 mg g⁻¹, respectively. The detection limits of the method were 12, 58, 24, 2, 7 and 36 ng L⁻¹, respectively, with a preconcentration factor of 25. The precision of this method was 1.7% (Mn), 2.9% (Cu), 5.9% (Mn), 3.8% (Mn), 6.2% (Mn) and 4.3% (Mn) with 9 determinations of 10 ng mL⁻¹ of target analytes, respectively. The method was successfully applied to the determination of trace metals in lake water, dried fish samples, certified reference materials of human hair and milk, and provided satisfactory results.     

The status of trace and minor elements in some Bangladeshi foodstuffs

An investigation is conducted on the status of trace and minor elements in some foodstuffs (cereals, vegetables, milk, egg and fish), commonly consumed in Bangladesh, using proton induced X-ray emission (PIXE) and radioisotope-induced X-ray fluorescence (XRF) techniques. In PIXE measurements, the samples were irradiated in air with 2.0 MeV (energy on the target) protons having the beam intensity of 30 nA for characteristic X-ray excitation, while in XRF analysis, the samples were excited for 5000 seconds with a 10 mCi Cd-109 annular X-ray source. The elemental concentration of K, Ca, Mn, Fe, Ni, Cu, Zn, Se, As, Br, Rb, Sr, Mo, and Pb were determined in the samples by comparison with X-ray yield curves constructed from IAEA and NBS standard reference materials. The validity of the analytical procedures (PIXE and XRF) followed in this study has been confirmed by comparative measurements of Cu, Zn and Mn in some varieties of rice with atomic absorption spectrophotometry. The results indicate that none of the food regimes investigated here is burdened with heavy metals beyond permissible limits except five species of vegetables with chromium having the range of 0.99–3.59 mg/kg compared to the literature value of 0.0–0.36 mg/kg (dry weight basis). An average value of 0.2 mg/kg of arsenic was observed both in IRRI (n=16) and local Aman (n=12) varieties of rice and only one hen egg contained 1.7 mg/kg of lead in yolk. The zinc content in some marine fish from Bay of Bengal was reported to be 5.4–19.5 mg/kg, whereas in the present study of sweet-water fish, the level is found to be 15.2–62.1 mg/kg (fresh weight basis) for five species. In human milk, both Cu (0.12–0.25 mg/l, n=8) and Zn (0.28–1.80 mg/l, n=8) levels appear to be almost half the literature values (n=25). On the other hand formula milk has higher values of Cu (0.32–1.63 mg/kg, n=16) and Zn (5.16–19.8 mg/kg, n=16).     

Evaluation of strontium isotope abundance ratios in combination with multi-elemental analysis as a possible tool to study the geographical origin of ciders

In order to evaluate alternative analytical methodologies to study the geographical origin of ciders, both multi-elemental analysis and Sr isotope abundance ratios in combination with multivariate statistical analysis were estimated in 67 samples from England, Switzerland, France and two Spanish regions (Asturias and the Basque Country). A methodology for the precise and accurate determination of the ⁸⁷Sr/⁸⁶Sr isotope abundance ratio in ciders by multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS) was developed. Major elements (Na, K, Ca and Mg) were measured by ICP-AES and minor and trace elements (Li, Be, B, Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Y, Mo, Cd, Sn, Sb, Cs, Ba, La, Ce, W, Tl, Pb, Bi, Th and U) were measured by ICP-MS using a collision cell instrument operated in multitune mode. An analysis of variance (ANOVA test) indicated that group means for B, Cr, Fe, Ni, Cu, Se, Cd, Cs, Ce, W, Pb, Bi and U did not show any significant differences at the 95% confidence level, so these elements were rejected for further statistical analysis. Another group of elements (Li, Be, Sc, Co, Ga, Y, Sn, Sb, La, Tl, Th) was removed from the data set because concentrations were close to the limits of detection for many samples. Therefore, the remaining elements (Na, Mg, Al, K, Ca, Ti, V, Mn, Zn, As, Rb, Sr, Mo, Ba) together with ⁸⁷Sr/⁸⁶Sr isotope abundance ratio were considered for principal component analysis (PCA) and linear discriminant analysis (LDA). Finally, LDA was able to classify correctly 100% of cider samples coming from different Spanish regions, France, England and Switzerland when considering Na, Mg, Al, K, Ca, Ti, V, Mn, Zn, As, Rb, Sr, Mo, Ba and ⁸⁷Sr/⁸⁶Sr isotope abundance ratio as original variables.     

Synthesis of nickel—copper—cobalt catalysts for deep oxidation of methane and optimization of their composition

Possibility of fabricating catalysts based on Ni, Cu, Co, and Mn oxides by the impregnation method was examined. The samples obtained were subjected to physicochemical analysis and their catalytic activities in deep oxidation of methane were compared. The composition of the Ni—Cu—Co catalytic system was optimized.     

A preliminary study on the effect of mineralization parameters on determination of metals in <Emphasis Type="Italic">Viscum album</Emphasis> species

An increasing interest in determination of various macro- and microelements in medicinal plants has been observed. The majority of studies are carried out using one mineralization method without any optimization. The present study demonstrates that changes in mineralization parameters can significantly affect the recovery of the elements determined. In the study, the dried plant material was mineralized in 12 ways and iron (Fe), copper (Cu), zinc (Zn), nickel (Ni) and manganese (Mn) levels were determined. The samples were mineralized in the dry or open microwave mode as well as 10 closed microwave modes. The influence of acid amounts, irradiation power and time, addition of hydrogen peroxide and perfluoric acid was examined. All parameters were shown to be critical — good efficiency was observed with larger amounts of acid. The determined content varied significantly in the same sample and were in the ranges (ug g⁻¹): 46–136 (Fe), 1.4–11.8 (Cu), 4.0–11.3 (Ni), 15.4–53.8 (Zn) and 9.5–67.6 (Mn). Increased irradiation resulted in the loss of copper and zinc and better recovery of nickel. The results demonstrate that such determinations should include the mineralization optimization step.      

Determination of Fe, Cu and Zn in sugar-cane spirits commercialized in Southeastern Brazil by TXRF

Total reflection X-ray fluorescence (TXRF) was used to determine simultaneously the concentration of Cu, Fe and Zn in seven sugar-cane spirit samples (“aguardente”), a processed alcoholic beverage made from the fermentation and distillation of sugar-cane juice. The limits of detection ranged from 35 to 8 ng^.ml^-1 for V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As and Se. Excluding Fe, Cu and Zn, the concentrations were below their limits. Two samples showed Cu concentrations higher than the value allowed by Brazilian legislation (5 μg^.ml^-1), and concerning Fe and Zn, no sample were above the limits permitted by WHO for drinking water (2 and 3 μg^.ml^-1, respectively). This revised version was published online in August 2006 with corrections to the Cover Date.