共查询到20条相似文献,搜索用时 0 毫秒
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Han-Wen Sun Ying Gao Chun-Gang Yuan Yan-Xin Zhang Li-Li Yang De-Qiang Zhang 《Analytical sciences》2002,18(3):325-328
A simple and sensitive method is described for the determination of trace lead in Chinese herbs by derivative atom trapping flame atomic absorption spectrometry (D-AT-FAAS) with a modified water-cooled quartz atom-trapping tube. The effects that influence the sensitivity of the derivative method, such as the trap position, the flame conditions and the collection time, were studied. The characteristics of the derivative atom trapping-atomic absorption signal and the linear nature of the working curve were investigated. The sensitivity of the derivative method is 2 or 3 orders of magnitude higher than that of FAAS, and the detection limit improved by 1 or 2 orders of magnitude. Satisfactory recoveries of 93.0-108.0% for lead were obtained by determining several Chinese herbs with a relative standard derivation range of 2.9 to 4.2%. 相似文献
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A procedure for the direct determination of zinc, cadmium and copper in air and water has been developed. The possible interference effects of numerous anions and cations have been investigated. Few interferences were found, and these were eliminated by the addition of EDTA. The sensitivities found were 2 p.p.b. for cadmium, 8 p.p.b. for copper and 2 p.p.b. for zinc. 相似文献
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建立火焰原子吸收光谱法测定锌合金中镁含量。选用10 mL盐酸溶液(1+1)溶解样品,加入5 mL质量浓度为100 g/L的LaCl3溶液,以消除铝对镁的化学干扰,在选定的仪器工作条件下进行测定。结果表明,镁的质量浓度在0~1.238 mg/L范围内与与吸光度具有良好的线性关系,相关系数为0.999 4,线性方程为Y=1.086 4X+0.018 5,方法测定下限为0.010 mg/L。样品测定结果的相对标准偏差为1.61%~3.45%(n=6),加标回收率为91.3%~94.7%。该方法准确度高,精密度好,满足锌合金中镁含量的日常检测要求。 相似文献
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Z. A. Khammas J. Marshall D. Littlejohn J. M. Ottaway S. C. Stephen 《Mikrochimica acta》1985,85(5-6):333-355
Summary Electrothermal atomic absorption spectrometry (ETA-AAS) and atomic emission spectrometry (ETA-AES) have been applied to the determination of copper in powdered milk. A homogeneous dispersion procedure for the preparation of the milk powder is described which was found to be simple, rapid and less susceptible to contamination than dry ashing or wet digestion methods. Both ETA-AAS and ETA-AES techniques were found to provide satisfactory results using conventional tube wall atomisation only when the method of standard additions was employed. The application of graphite probe atomisation in ETA-AES and ETA-AAS allowed the development of direct methods for the determination of copper in milk powder using aqueous standard calibration curves. The accuracy of the probe ETA-AAS method was confirmed using new reference materials prepared by the EEC Community Bureau of Reference. Acceptable agreement was obtained for the other procedures using a commercial milk powder sample with a copper content of 6.0g g–1. 相似文献
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Ewa Bulska Katarzyna Wróbel Adam Hulanicki 《Fresenius' Journal of Analytical Chemistry》1992,342(9):740-743
Summary The optimal conditions for the determination of aluminium and chromium in blood serum are proposed. Several sample pretreatment procedures for the purpose are compared. The best results are obtained by sample dilution with nitric acid (0.1 mol/l) and addition of Mg(NO3)2 as modifier with a magnesium concentration of 0.2 mg/ml. This procedure has been used for studying the intestinal intake of aluminium by patients after oral administration of aluminium compounds. 相似文献
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《Microchemical Journal》2008,88(2):128-131
The present work proposes a direct method based on slurry sampling for the determination of zinc and copper in human hair samples by multi-element sequential flame atomic absorption spectrometry. The slurries were prepared by cryogenic grinding and sonication of the samples. The optimization step was performed using univariate methodology and the factors studied were: nature and concentration of the acid solution, amount sample/slurry volume, sonication time, and particle size. The established experimental conditions are the use of a sample mass of 50 mg, 2 mol L− 1 nitric acid solution, sonication time of 20 min and slurry volume of 10 mL. Adopting the optimized conditions, this method allows the determination of zinc and copper with detection limits of 88.3 and 53.3 ng g− 1, respectively, and precision expressed as relative standard deviation (RSD) of 1.7% and 1.6% (both, n = 10) for contents of zinc and copper of 100.0 and 33.3 μg g− 1, respectively. The accuracy was checked and confirmed by analysis of two certified reference materials of human hair. The procedure was applied for the determination of zinc and copper in two human hair samples. The zinc and copper contents varied from 100.0 to 175.6 and from 3.2 to 32.8 μg g− 1, respectively. These samples were also analyzed after complete digestion in a closed system and determination by FAAS. The statistical comparison by t-test (95% confidence level) showed no significant difference between these results. 相似文献
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Hadla S. Ferreira Walter N.L. dos Santos Raigenis P. Fiuza Joaquim A. Nbrega Sergio L.C. Ferreira 《Microchemical Journal》2007,87(2):128-131
The present work proposes a direct method based on slurry sampling for the determination of zinc and copper in human hair samples by multi-element sequential flame atomic absorption spectrometry. The slurries were prepared by cryogenic grinding and sonication of the samples. The optimization step was performed using univariate methodology and the factors studied were: nature and concentration of the acid solution, amount sample/slurry volume, sonication time, and particle size. The established experimental conditions are the use of a sample mass of 50 mg, 2 mol L− 1 nitric acid solution, sonication time of 20 min and slurry volume of 10 mL. Adopting the optimized conditions, this method allows the determination of zinc and copper with detection limits of 88.3 and 53.3 ng g− 1, respectively, and precision expressed as relative standard deviation (RSD) of 1.7% and 1.6% (both, n = 10) for contents of zinc and copper of 100.0 and 33.3 μg g− 1, respectively. The accuracy was checked and confirmed by analysis of two certified reference materials of human hair. The procedure was applied for the determination of zinc and copper in two human hair samples. The zinc and copper contents varied from 100.0 to 175.6 and from 3.2 to 32.8 μg g− 1, respectively. These samples were also analyzed after complete digestion in a closed system and determination by FAAS. The statistical comparison by t-test (95% confidence level) showed no significant difference between these results. 相似文献
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An accurate and sensitive method for serum chromium determinations by graphite-furnace atomic absorption spectrometry is described. Samples containing a small amount of magnesium nitrate as an ashing aid/matrix modifier are lyophilized and dry-ashed in silanized quartz tubes; the residue is dissolved in 0.1 M HCl. Because of the very low levels of chromium in serum, strict contamination control measures must be used throughout the procedures for collection, storage, preparation and quantitation. Standard curves are prepared by using a bovine serum pool, which also serves as a quality control measure. The uniform nature of sera obviates the need to use the method of standard additions. The detection limit of the method is about 0.03 ng ml?1 Cr and the accuracy of the method is evaluated by comparison with stable-isotope-dilution mass spectrometry. 相似文献
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A method for the determination of copper in some sulfide minerals (lorandite, realgar, orpiment, marcasite, stibnite, galenite and sphalerite) by Zeeman electrothermal atomic absorption spectrometry is presented. After the dissolution of samples, copper was extracted with sodium diethyldithiocarbamate into different organic solvents (carbon tetrachloride, chloroform and methylisobutyl ketone) at pH 11.0–12.0. The procedure was verified by standard addition. The standard deviation (SD) for 0.5 ng Cu is 0.01 ng, the relative standard deviation ranges from 3.5 to 5.5% and the detection limit of the method, calculated as 3 SD of the blank, was found to be 0.05 μg · g–1. 相似文献
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An efficient method was developed for the determination of nanogram levels of lithium in biological samples. Serum samples from human subjects from southeastern Spain, treated or not treated with lithium carbonate, were analyzed by electrothermal atomic absorption spectrometry. The samples were previously treated with a matrix modifier consisting of 0.1% Triton X-100 and injected through a graphite tube with L'vov platform. The Li concentrations measured by the procedure described for the 3 certified reference samples used were not significantly different (p > 0.05) than certified levels. Sample recoveries and variability during several days, with coefficients of variation from 4.00 to 14.8%, demonstrated the reliability and accuracy of this technique. Mean Li concentration determined in the serum of individuals with psychiatric disorders treated with Li (n = 117, 5.077 +/- 1.795 microg Li/mL) was significantly higher (p < 0.001) than that in individuals not treated with Li (n = 24, 1.902 +/- 2.054 ng Li/mL). 相似文献
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A method for the determination of copper in some sulfide minerals (lorandite, realgar, orpiment, marcasite, stibnite, galenite
and sphalerite) by Zeeman electrothermal atomic absorption spectrometry is presented. After the dissolution of samples, copper
was extracted with sodium diethyldithiocarbamate into different organic solvents (carbon tetrachloride, chloroform and methylisobutyl
ketone) at pH 11.0–12.0. The procedure was verified by standard addition. The standard deviation (SD) for 0.5 ng Cu is 0.01
ng, the relative standard deviation ranges from 3.5 to 5.5% and the detection limit of the method, calculated as 3 SD of the
blank, was found to be 0.05 μg · g–1.
Received: 26 May 1997 / Revised: 10 September 1997 / Accepted: 16 September 1997 相似文献
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Manganese is determined in serum and urine by graphite-furnace atomic absorption spectrometry after dilution (1 + 1) with distilled water. Simple aqueous standards are used for calibration. Background absorption from the matrix is decreased by attention to the heating programme, sample dilution and gas flow-rate during atomisation. Remaining background absorption is removed by a deuterium-arc background correction system. To obtain accurate results, great care is needed in collecting samples to avoid contamination. Blood is collected through a plastic cannula, because stainless steel needles introduce considerable contamination. The mean normal concentration of manganese in serum was found to be 0.58 μg l?1 (it- = 9) which is in agreement with other literature values. For urine, the mean normal concentration found was 0.7 μg l?1 (it- = 16). Patients on total parenteral nutrition with manganese supplements show elevated serum and urine manganese concentrations. 相似文献
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Robert F. M. Herber Herman J. Pieters Jaap W. Elgersma 《Fresenius' Journal of Analytical Chemistry》1982,313(2):103-107
Summary A comparison of performance characteristics of ICAP-AES and ETA-AAS experienced in analyzing Cu and Zn in blood serum is described. Accuracy and precision were evaluated by a statistical procedure permitting graphical representation of the results. It was concluded that ETA-AAS is very suitable for monitoring and screening purposes in toxicology and clinical chemistry whereas ICAP-AES is to be preferred when more precise determinations are required.
Vergleich von AES mit induktiv gekuppeltem Argonplasma und AAS mit elektrothermischer Atomisierung für den Fall der Kupfer- und Zinkbestimmung im Serum
Zusammenfassung Die Leistungsfähigkeit der beiden Methoden wurde verglichen, wobei Richtigkeit und Reproduzierbarkeit statistisch mit graphischer Darstellung der Ergebnisse ausgewertet wurden. Als Schlußfolgerung ergab sich, daß sich die ETA-AAS als Überwachungs- und Screeningverfahren in der Toxikologie und klinischen Chemie eignet, während für höhere Präzision die ICAP-AES vorzuziehen ist.相似文献
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Summary Ground samples (150m, 0.5 g) are decomposed in a mixture of HF and HNO3 acids followed by evaporation to dryness, dissolution of the residue in dilute HNO3 acid, and dilution to 50 ml. Spectral interferences of 14 tested elements are negligible for AAS but in some cases (Nb, Ti, Zr) minor spectral corrections must be made for plasma techniques depending on the level of interferent and analyte. Nonspectral (matrix) interferences at the 1000g/ml interferent level are all less than 3.5% relative for AAS and less than 5% relative for ICP (except for Ca, Li, and Na where the effects are depressions of 7 to 10% relative). Matrix effects for DCP at the same interferent level are generally more pronounced and amount to enhancements of 5 to 15% relative for 11 of the 14 elements tested. Plasma matrix effects, especially alkali effects, can be compensated by the use of an alkali-aluminum buffer medium (1000g Na/ml plus 500g Al/ml as used in this study), a procedure which is most useful for the DCP approach. Copper can be determined down to 10 ppm in the original sample. A comparison of results shows AAS and ICP to be in good agreement with the DCP being slightly less accurate, although the differences in results may be of little practical significance. In terms of freedom from spectral and non-spectral interference, AAS was judged to have a slight advantage for copper.
Presented at the 9th International Symposium on Microchemical Techniques, Amsterdam, August 28–September 2, 1983. 相似文献
Bestimmung von Kupfer in Gläsern durch Flammen-Atomabsorption und Plasma-Emissions-Spektrometrie
Zusammenfassung Gemahlene Proben (150m, 0,5 g) werden in einem Gemisch aus HF und HNO3 aufgeschlossen, zur Trockne verdampft, in verd. HNO3 gelöst und auf 50 ml verdünnt. Spektrale Interferenzen 14 geprüfter Elemente sind bei der AAS ohne Belang, aber in manchen Fällen (Nb, Ti, Zr) sind je nach der Größenordnung der Störfaktoren geringe spektrale Korrekturen erforderlich. Nichtspektrale (der Matrix zuzuschreibende) Störfaktoren in der Größenordnung von 1000g/ml bewirken weniger als 3,5% rel. Abweichung bei der AAS und weniger als 5% rel. bei ICP (inductively coupled plasma) (ausgenommen Ca, Li und Na, die eine Minderung der Werte um 7–10% bewirken). Matrixeffekte bei DCP (direct coupled plasma) bei gleicher Größenordnung des Störfaktors sind im allgemeinen stärker ausgeprägt und bewirken bei 11 von 14 geprüften Elementen Steigerungen um 5–15% rel. Plasma-Matrix-Effekte, besonders Alkali-Effekte lassen sich mit Hilfe eines Puffermediums (1000g Na/ml+500g Al/ml) kompensieren, was sich vor allem bei DCP bewährt hat. Cu kann bis zu 10 ppm in der ursprünglichen Probe bestimmt werden. Die Ergebnisse von AAS und ICP stimmen gut überein mit denen von DCP, die etwas weniger genau sind; diese Differenzen dürften aber praktisch nur wenig bedeuten. Abgesehen von spektralen Störungen erwies sich AAS für Cu etwas vorteilhafter.
Presented at the 9th International Symposium on Microchemical Techniques, Amsterdam, August 28–September 2, 1983. 相似文献
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Arc-nebulization (a thermal nebulization technique) is used to form an aerosol of cadmium, lead and zinc. An open arc chamber of simple operation and an ejector of high efficiency are described which are adaptable for use with any flame atomic absorption spectrometer. Limits of detection better by one or two orders of magnitude than those achieved by conventional flame a.a.s. methods were obtained viz., 43 ng Pb, 5 ng Cd, 7 ng Zn (equivalent to 0.7, 0.08 and 0.11 ppm, respectively, in copper). Calibration with matrix-free solutions was possible for lead and cadmium but not for zinc. The spectral interference of copper on absorbance at the most sensitive zinc line (213.856nm) and the efficiency of arc nebulization of cadmium are also discussed. 相似文献
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Henryk Matusiewicz Ralph Sturgeon Van Luong Kathy Moffatt 《Fresenius' Journal of Analytical Chemistry》1991,340(1):35-40
Summary A simple method is described for the atomic absorption (AA) determination of Cu, Fe, Mn and Zn in river and estuarine water using two atom trapping techniques: a water-cooled dual silica tube and a commercially available double-slotted quartz tube mounted in an air-acetylene flame. Rapid, accurate analyses can be achieved using continuous aspiration. The concentration detection limits were 0.9, 1.5 and 0.3 ng ml–1 for Cu, Mn and Zn, respectively, using a 2 min in situ preconcentration time with the dual silica tube atom trap and 4.0, 12.1, 2.0 and 1.2 ng ml–1 for Cu, Fe, Mn and Zn, respectively, using the double-slotted quartz tube. The relative standard deviations are of the order of 2.9–6.9% for both techniques. The accuracy was assessed by analyses of NRCC SLRS-2 riverine and SLEW-1 estuarine water reference materials. Basic performance characteristics are also given for Ag, Bi, Cd, In, Pb and Tl using the dual silica tube atom trap. 相似文献