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1.
Urine levels of aluminum after drinking tea 总被引:2,自引:0,他引:2
Jun Wu Chao Yan Zhou Ming Keong Wong Hian Kee Lee Choon Nam Ong 《Biological trace element research》1997,57(3):271-280
A microwave-assisted acid digestion procedure coupled with a graphite furnace atomic absorption method has been applied in
the determination of aluminum (Al) in urine to verify the correlation of free forms of Al in tea infusions and urinary excretion
of Al. Significant urinary Al excretion has been found in 24-h urine of four volunteers after tea drinking. However, the difference
in amount of Al excretion in urine between the consumption of Oolong (black tea) and Long-Jin (green tea), each of them with
unique Al contents and species, was not significant. These findings indicated that the high levels of free Al species in tea
infusions did not result in significant change in urinary excretion of the metal, possibly owing to the transformation by
ligands present in food and the gastrointestinal tract (GIT). However, it could not be assumed that there was no big difference
in absorption of the metal in the human body if fractions of consumed Al retained in the body or excreted by bile or feces
were considered. 相似文献
2.
目的:本文着重研究利用石墨炉原子吸收光谱法测定虾产品中铝,对测定条件进行优化选择,达到快速、准确,以弥补国家标准检测方法中没有虾产品中铝检测方法的不足。方法:利用混合酸硝酸-高氯酸对样品进行消化处理,无基体改进剂,利用石墨炉原子吸收光谱仪进行定量检测。结果:在优化干燥、灰化、原子化、除残四个步骤的时间和温度的实验条件后,铝含量在0.0-50.0μg/L范围内呈线性关系,相关系数达到r=0.9990,最低检出限为0.54 ng/mL,铝的特征质量为5.0 pg。相对标准偏差为3.83%-6.42%,虾产品中铝含量测定回收率为90.7%-105.6%。结论:本法方便准确,灵敏度高,并有较高的回收率,可作为日常检测使用。 相似文献
3.
Terken Baydar Gönül Şahin Ahmet Aydïn Aşkïn Işïmer Nilgün Atakam 《Biological trace element research》1998,64(1-3):37-42
The Al content of 18 patch test allergens were measured by electrothermal atomic absorption spectrophotometry. It was found
that these preparations contained Al in various amounts. We conclude that the presence of Al in patch test allergens may interfere
with the diagnosis and evaluations of patients to whom the test is applied. 相似文献
4.
Wael I. Mortada Mohammed M. Hassanien Ahmed A. El-Asmy 《Journal of trace elements in medicine and biology》2013,27(4):267-272
A highly sensitive and selective technique for the speciation of platinum by cloud point extraction prior to determination by graphite furnace atomic absorption spectrometry (GFAAS) was described. The separation of Pt(II) from Pt(IV) was performed in the presence of 4-(p-chlorophenyl)-1-(pyridin-2-yl)thiosemicarbazide (HCPTS) as chelating agent and Triton X-114 as a non-ionic surfactant. The extraction of Pt(II)–HCPTS complex needs temperature higher than the cloud point temperature of Triton X-114 and pH = 7, while Pt(IV) remains in the aqueous phase. The Pt(II) in the surfactant phase was analyzed by GFAAS, and the concentration of Pt(IV) was calculated by subtraction of Pt(II) from total platinum which was directly determined by GFAAS. The effect of pH, concentration of chelating agent, surfactant, and equilibration temperature were investigated. An enrichment factor of 42 was obtained for the preconcentration of Pt(II) with 50 mL solution. Under the optimum experimental conditions, the calibration curve was linear up to 30 μg L?1 with detection limit of 0.08 μg L?1 and the relative standard deviation was 1.8%. No considerable interference was observed due to the presence of coexisting anions and cations. The accuracy of the results was verified by analyzing different spiked samples (tap water, blood plasma and urine). The proposed method was applied to the speciation analysis of Pt in blood plasma and urine with satisfactory results. 相似文献
5.
A. M. Massadeh M. Tahat Q. M. Jaradat I. F. Al-Momani 《Soil & Sediment Contamination》2004,13(4):347-359
This study evaluates the amount and distribution of Pb and Cd in roadside soils adjacent to two main roads in Irbid, Jordan, from October 2001 to July 2002. A total of 260 samples were collected from Irbid-Howara Street and Yarmouk University Street. Lead and Cd content were measured using Graphite Furnace Atomic Absorption Spectrometry. The environmental significance of this study is discussed in terms of the influence of traffic density on Pb and Cd concentrations in roadside soils, and enrichment factors were calculated to evaluate the degree of pollution. The accuracy of the results obtained has been examined and two standard reference materials, CRM 142 R (soil) and SRM 2709 (soil), were analyzed to confirm the accuracy of the results. The precision of the measurements was assessed in terms of relative standard deviation (RSD) using five replicate analyses of samples collected from the roadside sites. RSD values for Pb and Cd were found to be less than 6%. The overall Pb concentration in roadside soil samples was 325 and 431 μg g?1 for Pb and 1.142 and 1.135 μg g?1 for Cd in Yarmouk University Street and Irbid-Houwa Street, respectively. Results indicated that levels of Pb and Cd were decreasing as the distance from the road increases. Enrichment factor results were 655 and 826 for Pb, and 252 and 237 for Cd in Yarmouk University Street and Irbid-Houwa Street, respectively. 相似文献
6.
The selenium determination in biological materials by the classical fluorometric method (FM) is time-consuming and also hazardous,
as it requires the destruction of the organic matrix samples with hot HNO3/HClO4 mixtures prior to analysis. Accordingly, commercial analytical laboratories are increasingly using faster instrumental methods;
for sample digestion, avoid using HClO4. Because of these procedural changes, the results obtained by commercial laboratories may be unreliable, especially for samples
containing Se in organic forms. One such “difficult” substrate is Se yeast, which contains most of its Se as selenomethionine.
To establish which methods for Se analysis and sample digestion are applicable, samples of Se yeast and of selenomethionine
standards were sent to laboratories employing either flame atomic absorption spectrometry (FAAS), inductively coupled plasma-mass
spectrometry (ICP-MS), or hydride generation atomic absorption spectrometry (HGAAS). The result were compared with those obtained
by FM and non-destructive instrumental neutron activation analysis (INAA). ICP-MS, after microwave digestion of sample with
HNO3/H2O2, produced results within 5% of the expected values, as did those obtained by FM and INAA. With FAAS, acceptable results were
obtained after digestion with HNO3/HCl. With HGAAS, sample digestion with HNO3/H2O2 produced values that were systematically elevated by about 10% and exhibited standard deviations of ≥10%. Thus, current methods
of sample digestion are applicable for Se yeast analysis by ICP-MS and FAAS, but not by HGAAS. 相似文献
7.
Longitudinal and lateral variations in Al concentration in several large animal (bovine and caprine) long bones (tibia and
femur) and several human clavicle bones were examined using a sensitive analytical method based on electrothermal atomization
atomic absorption spectrometry with Zeeman background correction. Bone segments were carefully removed using special tools
free of significant Al contamination, freeze-dried, and digested overnight at room temperature in concentrated HNO3. Bone digestates were analyzed for Al using simple aqueous calibration standards with a Ca(NO3)2 modifier. Mean bone Al concentrations were relatively low (<1 Μg/g, dry weight) in bovine and caprine long bones compared
to literature values for human bone samples. Longitudinal variations of Al in the animal bones examined appeared relatively
uniform compared to the human clavicle bones, where, in three of five cases, Al appeared enriched at the epiphyses (joints).
The Al “enrichment” was symmetrical with respect to both left and right clavicle bones. Aluminum concentrations at the mid-shaft
of the clavicle bone show less variation compared to whole bone studies, but considerable scatter is evident along the bone
length. The mean bone aluminum concentration in the five human subjects varied from 1 to 6 Μ/g dry weight. 相似文献
8.
Background and aimBee pollen is recognized to be a source of different nutrients, including minerals. As a food supplement, its quality and safety due to concentrations of essential macro- and microelements, and harmful trace elements has to be verified. Fast and simple element analysis of bee-collected pollen can be regarded as an important part of its quality assurance and control. The present study aimed at developping a new method for determination of selected elements (Ca, Cu, Fe, Mg, Mn, Zn) of bee pollen based on solvent extraction and completely avoiding a high temperature treatment with concentrated reagents. In addition, in vitro gastrointestinal digestion was used to assess bioavailability of elements from this food supplement.MethodsBee pollen samples were dried and pulverized. Total concentrations of Ca, Cu, Fe, Mg, Mn, and Zn were determined by flame atomic absorption spectrometry (FAAS) in sample solutions obtained by wet digestion (WD) in concentrated HNO3 or alternatively by solvent extraction (SE) with diluted solutions of HNO3. Gastrointestinal digestion was mimicked using simulated solutions of gastric and intestinal juices followed by determination of Ca, Cu, Fe, Mg, Mn and Zn concentrations in the bioaccessible fraction by FAAS.ResultsA new simple and fast method for determination of total concentrations of Ca, Cu, Fe, Mg, Mn, and Zn in bee pollen was developed and validated. The method combined room temperature, two-hour SE with 0.5 mol L−1 HNO3 with FAAS measurements versus simple standard solutions. It provided precision within 1–5 % and trueness better than 8%, and was shown to be suitable for fast analysis of different polyfloral bee pollens. In vitro gastrointestinal digestion revealed that elements were well (70–85 % for Ca, Mg) and fairly (27–43 % for Cu, Fe, Mn, and Zn) bioaccessible from bee pollen. By pouring with water and swelling overnight, bioaccessibility of studied elements from such prepared bee pollen was increased on average by less than 15 % (Mn), 20 % (Ca, Cu, Fe, Zn) or 30 % (Mn).ConclusionsAvoiding long-lasting, high-temperature wet digestion with concentrated reagents, the proposed sample treatment along with FAAS provided precise and true results of total concentrations of Ca, Cu, Fe, Mg, Mn, and Zn in bee pollen. The method was simple and fast, and enabled to analyze a higher number of samples. Simulated gastrointestinal digestion of bee pollen have shown for the first time that Ca and Mg are the most bioaccessible from this bee product. Bioaccessibility of Cu, Fe, Mg, and Zn from bee pollen are close to or lower than 40 %. 相似文献
9.
采用湿式消解法对金线莲药材进行处理,石墨炉原子吸收光谱法测定其铅(Pb)、铜(Cu)、镉(Cd)等重金属元素含量。结果表明,Pb、Cu、Cd 三种元素的原子化温度分别是2100、2200和1800 ℃,灰化温度分别是400、800和250 ℃。Pb、Cu、Cd三种元素的检出限分别为0.47、0.50、0.62 μg·L-1,其加标回收率在92.7%~94.0%之间,平均相对标准偏差为1.71%,说明仪器精密度良好,湿式消解-石墨炉原子吸收光谱法能有效测定金线莲药材中Pb、Cu、Cd含量。 相似文献
10.
A procedure using open digestion followed by flame atomic absorption spectrometry is described for measuring the total selenium
content of Se-enriched yeast. The limits of detection and quantitation were 2.5 mg/L and 5 mg/L Se, respectively. The signal
response was linear over the range of 5–50 mg/L Se, and the average recovery from spiked samples was 98.9%. The validated
method was used to measure the Se content of Se-enriched yeast reference material and produced a result of 2145±38 mg/kg (n=3), which is in good agreement with the certified level of 2125 ±65 mg/kg. 相似文献
11.
Nancy W. Alcock 《Biological trace element research》1987,13(1):363-370
Tissue digestion prior to analysis for trace metals is usually carried out with strong acids. Nitric acid, alone or in combination
with perchloric acid, is most commonly used. In addition to the laborious acid washing of all glassware prior to use, the
digestion necessitates exposure to potential environmental contamination. Use of perchloric acid mandates a specially constructed
hood with facilities for washing to remove acid deposits.
A simple digestion procedure using 30% hydrogen peroxide in polyethylene vials in an oven at approximately 75°C has been previously
described for the measurement of zinc in tissues using flame or flameless atomic absorption spectrophotometry and of selenium
in liver by flameless atomic absorption. Readings for reagent blanks were insignificant. The technique has been further developed
with a reduction in digestion time using 50% H2O2. Analysis of liver has been extended to include copper, manganese, and arsenic. Although the level of arsenic present was
too low to be detected, 50 and 100 ng of this element added to the liver powder was completely recovered.
The digest obtained when dissolved in appropriate solvent is suitable for analysis for multiple trace metals.
Author to whom all correspondence and reprint requests should be addressed. 相似文献
12.
Determination of trace lead in biological and water samples with dispersive liquid-liquid microextraction preconcentration 总被引:4,自引:0,他引:4
A new method for the determination of trace lead was developed by dispersive liquid–liquid microextraction preconcentration and graphite furnace atomic absorption spectrometry. In the proposed approach, 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP) was used as a chelating agent, and carbon tetrachloride and ethanol were selected as extraction and dispersive solvents. Some factors influencing the extraction efficiency of lead and its subsequent determination, including extraction and dispersive solvent type and volume, pH of sample solution, concentration of the chelating agent, and extraction time, were studied and optimized. Under the optimum conditions, the enrichment factor of this method for lead was reached at 78. The detection limit for lead was 39 ng L−1 (3σ), and the relative standard deviation (RSD) was 3.2% (n = 7, c = 10 ng mL−1). The method was successfully applied to the determination of trace amounts of lead in human urine and water samples. 相似文献
13.
《Saudi Journal of Biological Sciences》2017,24(3):589-594
A cloud point extraction (CPE) method was used as a pre-concentration strategy prior to the determination of trace levels of silver in water by flame atomic absorption spectrometry (FAAS) The pre-concentration is based on the clouding phenomena of non-ionic surfactant, triton X-114, with Ag (I)/diethyldithiocarbamate (DDTC) complexes in which the latter is soluble in a micellar phase composed by the former. When the temperature increases above its cloud point, the Ag (I)/DDTC complexes are extracted into the surfactant-rich phase. The factors affecting the extraction efficiency including pH of the aqueous solution, concentration of the DDTC, amount of the surfactant, incubation temperature and time were investigated and optimized. Under the optimal experimental conditions, no interference was observed for the determination of 100 ng·mL−1 Ag+ in the presence of various cations below their maximum concentrations allowed in this method, for instance, 50 μg·mL−1 for both Zn2+ and Cu2+, 80 μg·mL−1 for Pb2+, 1000 μg·mL−1 for Mn2+, and 100 μg·mL−1 for both Cd2+ and Ni2+. The calibration curve was linear in the range of 1–500 ng·mL−1 with a limit of detection (LOD) at 0.3 ng·mL−1. The developed method was successfully applied for the determination of trace levels of silver in water samples such as river water and tap water. 相似文献
14.
Michael Wilhelm Doris Höhr Josef Abel Friedrich K. Ohnesorge 《Biological trace element research》1989,21(1):241-245
Urinary aluminum (Al) excretion was studied in humans with normal and impaired renal function. Al was measured by atomic absorption
spectrometry. In healthy volunteers (n=50), renal Al excretion was 12.2±8.5 μg/24 h.
Two patients on plasma exchange therapy with normal renal function and an inadvertent load of 870 and 388 μg Al/treatment
showed a 23 and 14% positive balance until next treatment. 相似文献
15.
Determination of selenium in the human brain by graphite furnace atomic absorption spectrometry 总被引:2,自引:0,他引:2
Akiko Ejima Chiho Watanabe Hiroshi Koyama Kyoko Matsuno Hiroshi Satoh 《Biological trace element research》1996,54(1):9-21
For the investigation of neurological disorders, a development of simple and accessible methods for determining selenium in
human brain samples is required. We devised a method of determining selenium using graphite furnace atomic absorption spectrometry
(GFAAS). An electrodeless discharge lamp provided the sufficient sensitivity to determine brain selenium. The matrix interferences
were avoided by using high temperature, a prolonged pyrolysis step, and a palladium matrix modifier. The technique of standard
addition was used to evaluate the sample concentrations. The accuracy of the method was confirmed by a bovine liver reference
material. The detection limit of selenium was 0.04 ng. The determined selenium concentrations of human brain cortex and white
matter were higher than those of putamen (115–155 and 206–222 ng/g wet wt, respectively). These GFAAS values agreed with those
obtained by fluorometric analysis (r=0.91,n=10). Moreover, the GFAAS values were compatible to those reported by other researchers (99–274 ng/g wet wt), in which selenium
concentrations in putamen also tended to be higher than the other two regions. We conclude that GFAAS is useful for selenium
analysis in brain samples. 相似文献
16.
微波消解-火焰原子吸收光谱法测定蜂胶中金属元素含量 总被引:1,自引:0,他引:1
目的:测定一种原产地为加拿大的蜂胶中金属元素的含量,为进一步研究蜂胶营养价值提供数据,同时改进测量方法。方法:用微波消解法处理样品,用硝酸和过氧化氢的混合物作为消解剂进行微波消解,并优化消解条件,然后用火焰原子吸收光谱法测定蜂胶制品中钙、铁、镁、锌、钠、钾、铜的含量。结果:七种元素相对标准偏差为O.85%~2.33%(n=7),回收率在96.5%~104.7%之间。试验结果表明该蜂胶中含有丰富的金属元素,且与河南产蜂胶相比,加拿大产蜂胶中多种金属元素含量远低于河南产蜂胶。结论:使用本文方法测定蜂胶中的金属元素含量,结果准确,方法可靠。为进一步探讨蜂胶制品金属元素与其保健功能的关系提供了有用数据。 相似文献
17.
目的:测定一种原产地为加拿大的蜂胶中金属元素的含量,为进一步研究蜂胶营养价值提供数据,同时改进测量方法。方法:用微波消解法处理样品,用硝酸和过氧化氢的混合物作为消解剂进行微波消解,并优化消解条件,然后用火焰原子吸收光谱法测定蜂胶制品中钙、铁、镁、锌、钠、钾、铜的含量。结果:七种元素相对标准偏差为0.85%~2.33%(n=7),回收率在96.5%~104.7%之间。试验结果表明该蜂胶中含有丰富的金属元素,且与河南产蜂胶相比,加拿大产蜂胶中多种金属元素含量远低于河南产蜂胶。结论:使用本文方法测定蜂胶中的金属元素含量,结果准确,方法可靠。为进一步探讨蜂胶制品金属元素与其保健功能的关系提供了有用数据。 相似文献
18.
M. Torra M. Rodamilans J. Corbella R. Ferrer R. Mazzara 《Biological trace element research》1999,70(2):183-189
Plasma chromium levels were determined in 243 healthy subjects. The study group consisted of 134 men and 109 women, ages 19–71
yr, all residing in Barcelona in northeastern Spain. The study was designed to assess the reference levels for plasma chromium
and to investigate its relationships to age and sex. The assays were performed by means of a graphite-furnace atomic absorption
spectrometer. The mean plasma chromium concentration was 3.01 ±1.45 nmol/L, ranging from 0.6 to 6 nmol/L. The upper reference
values in the 0.95 percentile for this population was 5 nmol/L. No significant differences were observed with respect to the
subjects’ sex. 相似文献
19.
Introduction – To ensure food safety, accurate knowledge of the levels of several trace elements is necessary. This is also true for natural products of plants and resins used for human consumption or therapeutic treatment, like the mastic gum of Pistacia lentiscus. The rapid analysis of gum and resin matrices is a challenge because there are problems with the decomposition of such complicated matrices. Objective – To develop an efficient multielemental analytical method for the determination of trace elements and to compare different procedures for analyte extraction when microwave‐assisted digestion is applied. Methodology – The inductively coupled plasma atomic emission spectrometric (ICP‐AES) technique was applied and the optimum ICP conditions like radiofrequency power, argon flow rate and nebuliser sample uptake flowrate were found. The microwave‐assisted procedure was compared with that with conventional heating. Since mastic and resinous materials are difficult for dissolution and extraction of trace element, influential acid mixtures containing hydrofluoric acid proved to be capable of quantitative extraction of the analytes. Results – The digestion of mastic resin or similar matrices is significantly facilitated by using microwave radiation instead of conventional heating since the obtained recovery for several analytes is much higher. It was proved that the acid mixture of HCl–HNO3–HF was the most efficient for complete sample digestion and recovery of the analytes. Conclusions The performance characteristics of the developed method were evaluated against certified reference material and the method was proved reliable and applicable to the analysis of mastic gum and possibly to similar resinous matrices. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
20.
Size exclusion chromatography was used for the fractionation of the aqueous extracts taken from different soil horizons (LOf,
Oh, Ah, 15 and 35 cm). The aluminium content in the fractions was determined by graphite furnace atomic absorption spectrometry.
In the fractions obtained from the LOf, Oh and Ah horizons, a great part of the total aluminium was bound to organic molecules.
Over 90% of the aluminium in mineral soil solutions (15 and 35 cm depth) was of low molecular weight or associated with those
species. 相似文献