利用AES法和FLAA法测定底质中的铅

:利用萃取火焰原子吸光法和石墨炉原子吸光法 (标准添加法 )共同对底质中的 Pb进行测定 ,测定结果表明此方法能减少 Pb的基体干扰 。

Primary Speciation Analysis on 6 Kinds of Microelements in Glycyrrhiza uralensis Fisch.

[Objective]The aim was to analyze the primary speciation of 6 microelements in Glycyrrhiza uralensis Fisch. and provide theoretical basis for explaining pharmacodynamic principle of liquorice and discussing quality control of liquorice planting. [Method]The 6 elements Cu,Zn,Ca,Fe,Mg and Mn in roots of G.uralensis were extracted based on traditional decoction method and were separated into water-soluble state and suspension state by micro porous filtering film. The elements in water-soluble state were detected by flame atomic adsorption spectrophotometry （FAAS）. [Result]The results showed that extractive rates of the elements were in the range of 1.71%-60.06%,and immerse-residue ratio in 0.018 3-1.682 0; the results also indicated that the immerse-residue ratio of Zn was biggest （1.68）,Zn played an important medical role and might be considered as the best characteristic element in G.uralensis; the recoveries of the elements were ranged from 95.72% to 103.15% and relative standard deviations （RSD） were less than 2.38%. [Conclusion]Because of its high accuracy,FAAS method is feasible for analyzing primary speciation of microelements in G.uralensis.

Determination of the Trace Element Contents in Plants Using Atomic Absorption Spectrophotometer

The aim of the study is to investigate the contents of trace element Se, Cd, Pb in three plants including burdock, ginkgol and garlic via graphite furnace atomic absorption and standard addition method. The results show that Se in burdock stem, skin and leaf are 32.40, 48.63, 38.10 μg/g, respectively; Cd in burdock stem, skin and leaf are 0. 160 0, 0. 300 0, 0. 140 0 μg/g, respectively; Cd in burdock stem, skin and leaf are 2. 020, 3. 960, 2. 410 μg/g, respectively. In the ginkgo and ginko leaf, Se contents are 17.63 and 16.91 μg/g, respectively ; for Cd are 0. 181 0 and 0.2020μg/g, respectively ; for Pb are 3. 572 and 4. 021 μg/g, respectively. In garlic, Se, Cd and Pb are 73. 900 0, 6. 900 0 and 0. 390 0, respectively. All the standard deviations of measured results are below 2.3%, recovery rate are from 99% to 101%.

Determination of Five Metallic Elements in Guoshangye from Guizhou by Microwave Digestion-flame Atomic Absorption Spectrometry

In the study, the contents of 5 trace elements including Fe, Cu, Mg, Mn and Ca were directly analyzed by flame atomic absorption spectroscopy in Gu- oshangye. The sample was subjected to microwave digestion with HNO3 and H2O2, and detected by the standard curve method. The results showed that Guoshangye contained abundant trace elements which rates of these trace elements were in the curacy and satisfactory. were necessary for human. The recovery range of 96%-103%. The method is ac-

Determination of Ca,K,Mg and Fe in Four Fish Species by FAAS

A method for determining calcium （Ca）, potassium （K）, magnesium （Mg） and iron （Fe） in four fish species was opti- mized and validated. It included microwave mineralization of the samples and subsequent quantification by flame atomic absorption spectroscopy （FAAS） with Zeeman-effect background correction. Using HNO3 （65%） and H202 （33%） as extraction solutions, the optimal conditions of extraction were established as follows： 0.5 g of sample mass; microwave time program of 300 W/5 min and 600 W/5 min. The method was free of matrix interferences. The linear correlation coefficients were ≥0.9991, the recovery percentage of analytes was from 99.31% to 103.70% and the RSD （relative standard deviation） was lower than 2.06%. The detection limits obtained were 32.3, 43.2, 14.0 and 68.6ng mL^-1 for Ca, K, Mg and Fe in FAAS respectively. It is shown that the method is rapid, simple, sensitive and accurate. The method was applied to the studies of digestibility and measurement of these nutrients in samples of fish collected from Norway, Japan and China.

Germanium separation and purification by leaching and precipitation

In this research work, extraction and purification of germanium from zinc leach residues(ZLR) were investigated. The results of ICP, XRF, and atomic adsorption spectroscopy(AAS) tests show that contents of germanium, iron, lead, and zinc within the leaching residue were 105×10^(-6), 3.53%, 10.35%, and 8.8%, respectively. XRD results indicate that the main minerals were in different forms of sulfates(CaSO_4·2H_2O, PbSO_4 and ZnSO_4·6H__2O), silicate(SiO_2), and oxide(Fe_2O_3). Dissolution of leaching filter cake was carried out using 5 parameters and each in 4 levels(acid concentration, temperature, time, liquid-to-solid ratio, and stirring speed) by Taguchi method(L_(16)), and then optimization of the effective parameters by response surface method. Under optimum conditions, zinc and germanium dissolution efficiencies were 88.71% and 8%, respectively. Leaching tests with sulfuric acid(added di-ammonium oxalate monohydrate) and hydrochloric acid(HCl) on the residues obtained from previous-stage sulfuric acid dissolution, yielded germanium and iron recoveries of 83%, 88%, 40%, and 90%, respectively. Thus, leaching experiment with sulfuric acid(added di-ammonium oxalate monohydrate) was superior to that with hydrochloric acid due to high and low extraction amounts of germanium and iron, respectively. Precipitation experiments revealed that germanium purification with tannic acid presented a better result compared to sodium hydroxide and ammonia. Under optimum conditions, contents of germanium and iron in the solution after precipitation were 0.1505% and 14.7% with precipitation yields of 91% and 52%, respectively.

Comparison between sequential and single extraction procedures for metal speciation in fresh and dried Sedum Plumbizincicola

Sequential and single extraction procedures were applied to both fresh and dried Sedum Plumbizincicola leaves and stems.The extractants, different from those of soil, sediment or sewage sludge metal fractions, were water, 80%(v/v) ethanol, 1 mol/L Na Cl,2% HAc and 0.6 mol/L HCl. Zn, Cd and Cu in the extracts and samples were measured by flame atomic adsorption spectrometry. In sequential extraction procedures, water soluble form and ethanol soluble form are the main fractions for Zn, while water soluble form and Na Cl soluble form for Cd, and comparatively uniform distribution for Cu with the residue form most and HCl soluble form second. Single extraction procedures are used to compare the extraction efficiencies of the five reagents to screen appropriate extractants and operating conditions for liquid extraction to deal with large amount of harvested metal-contained biomass, which will pose a threat to the environment if treated improperly. The sequences of extraction efficiencies are HCl>Na Cl≈HAc>Water≈Ethanol for Zn and HCl≈Na Cl≈HAc>Water>Ethanol for Cd. As for Cu, all the five extractants cannot effectively extract Cu, but HCl achieves a higher efficiency(>70% in fresh samples, and 45%-60% in dried samples). Besides, extraction efficiencies for most extractants in fresh samples are higher than those in dried samples, and extraction efficiencies of stems and leaves for the five extractants are close. The two extraction procedures can obtain high degree of accuracy with the relative standard deviation(RSD)lower than 10%, and metal recoveries are controlled between 80%-120% with most of 90%-110%.

The Use of Multiwalled Carbon Nanotubes Mini Column for Preconcentration of Trace Metal Ions in Tap Water of Khartoum City and Their Determination by Flame Atomic Absorption Spectrometry （FAAS）

The adsorption behavior of multiwalled carbon nanotubes （MWNTs） toward heavy elements has been investigated systemically, and a new method has been developed for the determination of trace elements in water samples based on preconcentration with mini-column packed with MWNTs prior to its determination by flame atomic absorption spectrometry （FAAS） The recommended parameters of proposed method influencing the preconcentration of the analytes, such as pH of the sample, sample flow rate and volume, elute solution and interfering ions, have been used. Under the optimized conditions, the calibration graphs were linear with the correlation coefficient range 0.9981-0.9995. According to the results, the metals were found 0.019-0.051, 0.011-0.031, 0.00-0.081, 0.00-0.0002, 0.007-0.0925, 0.00-0.0104 μg/L in water samples for Pb, Mn, Zn, Cd, Fe, Cu respectively. The percentage relative standard deviation （%RSD） for five replicate samples were 〈 5% in all cases. The method has been successfully applied to the determination of trace elements in some environmental samples with satisfactory results.

Effect of PSA tin plating process on trace lead in tin coating

In this paper,effects of conditions in phenol sulfonic acid(PSA) plating for tin coating of MR low carbon aluminum killed steel on trace Pb were examined.Trace Pb was measured by atomic absorption spectrometry(AAS)and glow discharge spectrometry,and coating morphology was observed by scanning electronic microscopy(SEM).Corrosion resistance of the tin coating was analyzed by electrochemical methods.The results indicated that Pb content in the tin coating reduced as bath temperature increased.When the temperature exceeded40 ℃,the grains in the coating were coarse and loose,reducing the corrosion resistance.As current density increased,Pb content increased rapidly,while low current density plating could lead to drain regions.The plating speed had no obvious effect on trace Pb in tin coating.In the tin plating layer,Pb was enriched at the surface and gradually reduced to zero along the depth.At bath temperature of 40 ℃ and current density of 20 A·dm^(-2),the amount of Pb could be less than 100 mg·kg^(-1) with excellent corrosion resistance.

Determination of Exchangeable Ca and Mg Contents in Tobacco Growing Area by Atomic Absorption Spectrometry

[Objective] A method for the determination of exchangeable Ca and Mg contents in tobacco growing area by atomic absorption spectrometry was established. [Method] Factors in the extraction process, sample weight, ammonium acetate volume, extraction time and strontium chloride volume were tested, and the stability, precision and accuracy of the method were also investigated. Meanwhile, samples at different pH values were determined by this method. [Result] The results showed that this method operation has simple operation with good stability and high precision. [Conclusion] This method could be applied to determine exchangeable Ca and Mg contents in tobacco growing area.

Chitosan Removes Toxic Heavy Metal Ions from Cigarette Mainstream Smoke

This study investigated the removal of heavy metal ions from cigarette mainstream smoke using chitosan. Chitosan of various deacetylation degrees and molecular weights were manually added to cigarette filters in different dosages. The mainstream smoke particulate matter was collected by a Cambridge filter pad, digested by a microwave digestor, and then analyzed for contents of heavy metal ions, including As（Ill/V）, Pb（II）, Cd（II）, Cr（III/VI） and Ni（II）, by graphite furnace atomic absorption spectrometry （GFAAS）. The results showed that chitosan had a removal effect on Pb（II）, Cd（II）, Cr（III/VI） and Ni（II）. Of these, the percent re- moval of Ni（II） was elevated with an increasing dosage of chitosan. Chitosan of a high deace tylation degree exhibited good binding performance toward Cd（II）, Cr（III/VI） and Ni（II）, though with poor efficiency for Pb（II）. Except As（III/V）, all the tested metal ions showed similar tendencies in the growing contents with an increasing chitosan molecular weight. Nonetheless, the percent removal of Cr（III/VI） peaked with a chitosan molecular weight of 200 kDa, followed by a dramatic decrease with an increasing chitosan mo- lecular weight. Generally, chitosan had different removal effects on four out of five tested metal ions, and the percent removal of Cd（II）, Pb（II）, Cr（III/VI） and Ni（II） was approximately 55%, 45%, 50%, and 16%, respectively. In a word, chitosan used in cigarette filter can remove toxic heavy metal ions in the mainstream smoke, improve cigarette safety, and reduce the harm to smokers.

Preparation and antimicrobial ability of natural porous antibacterial materials

The liquid ion exchange method, solid salt melt method and dry-wet circulation method were used to prepare natural porous antimicrobial materials with natural minerals, such as zeolite, spilite, palygorskite and montmorillonite, respectively. Atomic absorption spectrum and X-ray diffraction analysis were carried out to investigate the effects of Ag^＋ , Cu^2＋ and Zn^2＋ on antimicrobial abilities of natural porous minerals, and the effect of preparation method on ion exchange capacity of antimicrobial material, respectively. The results show that for the ion exchange capacity, clay mineral is higher than fibrous mineral, i.e. both zeolite and montmorillonite are higher; the antimicrobial ability of material with Ag^＋ is the bests the exchange capacities of materials with Cu^2＋ or Zn^2＋ are all higher, but the antimicrobial ability of Cu^2＋ is better than that of Zn^2＋ .

Effect of sample treatment on determination of arsenic （Ⅲ） and arsenic （Ⅴ） in aqueous and tissue samples by hydride generation atomic absorption spectrometry

The purpose of this procedure was to optimize and improve a method that used for the determination of arsenic （Ⅲ） and arsenic （Ⅴ） in biological and environmental samples. The method is based on hydride generation and atomic absorption spectrometry. For both As （Ⅲ） and As （Ⅴ） the parameters such as NaBH4, HCI concentration, and pH were optimized. Absorption signal of As （Ⅴ） was approximately 17% of As （Ⅲ） signal. Therefore, for estimation of As （Ⅲ） and As （Ⅴ） concentrations in various samples the difference between the absorbance obtained for arsenic, without and with previous treatment of samples with potassium iodide （KI）, can be applied. The calibration graphs were linear （r〉0.99）, and the detection limits of the method based on three times the standard deviation of the blank were 0.14 and 0.64 μL^-1 for As （Ⅲ） and As （Ⅴ）, respectively. The relative standard deviation （R.S.D.） of measurements was less than 10%. As a means of checking performance method, water samples were spiked with known concentrations of both As （Ⅲ） and As （Ⅴ）, and recovery above 94% was obtained. The proposed method was applied successfully to determine inorganic As （Ⅲ） and As （Ⅴ） in various environmental and total As in biological samples.

Prediction of XRF analyzers error for elements on-line assaying using Kalman Filter

Determination of chemical elements assay plays an important role in mineral processing operations.This factor is used to control process accuracy,recovery calculation and plant profitability.The new assaying methods including chemical methods,X-ray fluorescence and atomic absorption spectrometry are advanced and accurate.However,in some applications,such as on-line assaying process,high accuracy is required.In this paper,an algorithm based on Kalman Filter is presented to predict on-line XRF errors.This research has been carried out on the basis of based the industrial real data collection for evaluating the performance of the presented algorithm.The measurements and analysis for this study were conducted at the Sarcheshmeh Copper Concentrator Plant located in Iran.The quality of the obtained results was very satisfied;so that the RMS errors of prediction obtained for Cu and Mo grade assaying errors in rougher feed were less than 0.039 and 0.002 and in final flotation concentration less than 0.58 and 0.074,respectively.The results indicate that the mentioned method is quite accurate to reduce the on-line XRF errors measurement.

Influence of Cu（II） on Ag（I） Recovery by Photocatalytic Reduction Method with TiO2 Suspension

Photocatalytic reduction method using TiO2 suspension for removal as well as possibly recovery of silver （Ag（I）） in the presence of Cu（II） is examined. The photocatalytic reduction was performed by batch technique in a closed reactor equipped with UV lamp. The concentration of unreduced Ag（I） was analyzed by atomic absorption spectrophotometry method. The research results indicate that Ag（I） in the solution can be removed and recovered effectively as silver metal Ag（0） deposited on the surface of TiO2 for photocatalytic reduction. In addition, the presence of Cu（II） ion with increasing concentration leads to a proportional decline in Ag（I） photoreduction due to the prominent competition in the adsorption on the surface of TiO2. The effectiveness of Ag（I） ion photoreduction in the presence of Cu（II） ion is strongly influenced by solution pH and the highest photoreduction is obtained at pH 5 - 8, which is related with the speciation ofAg（I）, TiO2 surface as well as Cu（II） in the solution.

Preparation and adsorption behaviors of Cu(Ⅱ) ion-imprinted polymers

Imprinted polymers were prepared for selective removal of Cu（Ⅱ） ions from metal solutions. Three ion-imprinted polymers were synthesized with methacrylic acid （MAA）, acrylamide （AA） and N,N＇-methylenebisacrylamide （MBAA） respectively as the functional monomers, ethleneglycoldimethacrylate （EGDMA） as the cross-linking agent, 2,2＇- azobisisobutyronitrile （AIBN） as the initiator and Cu （Ⅱ） ion as the imprint ion. The template Cu （Ⅱ） ion was removed from the polymer by leaching with a liquid of a 1：1 volumetric ratio of HCl to ethylenediaminetetraacetic acid （EDTA）. The capacity and selectivity of Cu（Ⅱ） ion adsorption were investigated with the three imprinted polymers and their non-imprinted counterparts. The polymers have a maximum adsorption capacity at pH 7.0. The isotherm of their batch adsorption of Cu（Ⅱ） ions shows a Langmuir adsorption pattern. Imprinted polymers all have a much higher capacity and higher selectivity of Cu（Ⅱ） adsorption than nonimprinted ones. MAA polymer benefits the most from imprinting. Imprinted MAA polymer has the highest selectivity when used to rebind Cu （Ⅱ） ion from an aqueous solution in the presence of other metal ions. Ion imprinting can be a promising technique of preparing selective adsorbents to separate and preconcentrate metal in a medium of multiple competitive metal ions through solid phase extraction （SPE）.

Detection of Total Phenols, Essential and Toxic Elements in Latvian Whole Grain Bread

A survey was carried out with the aim of assessing the level of the total phenolic compounds （TPC）, essential （Na, K, Ca, Mg, Cu, Zn） and toxic （Cd and Pb） elements in 10 Latvian whole grain rye and/or wheat flour bread samples, obtained from the local market. The quantities of the TPC were determined by spectrophotometry. Mineral content was determined by flame photometry, flame atom absorption spectrometry （FAAS） and electrothermal atomic absorption spectrometry （ETAA） after wet digestion in concentrated HNO3. The values were comparable to the literature data. The average content in all the samples was （on a basis of weight of the product） 547 ± 28 mg/100 g for Na; 280 ±20 mg/100 g for K; 32 ± 2 mg/100 g for Ca; 88 ±5 mg/100 g for Mg; 0.49 ± 0.09 mg/100 g for Cu; 1.6 ±0.2 mg/100 g for Zn. Both Pb and Cd were determined below the limit of detection （LOD 5 0.10 mg/100 g）. The LOD values were determined for each element. The TPC content in defatted samples was slightly lower than the non-defatted ones, showing the dependence on the sample preparation. The calculated average levels of the elements were compared with the maximum levels recommended or regulated by the national legislation.

Escamoles Ant Eggs Liometopumapiculatumm Source of Metal Ions for Human Health

The earth crust is believed to be made of a mass of minerals and is matched by their importance in human life. The human body, depend like other leaving organisms, on several minerals as essential constituents of its existence. Metal ions in foodstuff are in different chemical forms, as inorganic salts or organic molecules or complexes with other compounds such as proteins, amino acids, enzymes and some vitamins, among others, that play an important role in human health. Entomophagy, insect consumption by several ethnic groups in Mexico as cultural tradition since prehispanic era represent an option for population to obtain the minerals needed by the body to keep a good health. Escamoles ant eggs of the Liometopumapiculatum M genus, much appreciated either at rural communities as well as in urban cities, contain minerals with a favorable effect in human health. The aim of this study was to investigate the mineral composition of Escamoles and the benefits which can provide to the human body. Sampling was at an arid region of the Hidalgo state on April 2012. Minerals in dry basis, determined by atomic absorption spectrophotometry, with the exception of phosphorus content, obtained from a triple acid digested extract and determined colorimetrically. Data of mineral analysis in dry basis of Escamoles were： total minerals 5.92%; Na 0.079%; K 0.075%; Ca 0.097%; P 0.701%; Fe 0.021%; Zn 0.035% Cu 0.009%; Mg 0.998%; Mn 0.002%. Minerals quantify are not equal to total ash contained because not all of them were assess determined. Elements concentration depends not only on the total mineral composition of foodstuff the inorganic or organic form or interaction among metal ions, but also on their availability and avail of them. Minerals in Escamoles ant eggs have a considerable influence in the condition of human health.

Uncertainty Estimation for the Determination of Trace Heavy Metals in Human Hair by Flame and Electrothermal Atomic Absorption Spectrometry

Trace element analysis on hair samples has been widely used to assess wildlife and human exposure to different contaminants present in the environment or at the workplace. Pollutants due to the presence of toxic metals in environment not only enter the body by breading, water, and foodstuff accumulates in hair, but they could be adsorbed directly on the hair from environment. In order to remove adsorbed elements and thus determine the internally bound elements correctly, hair sample must be washed. In the present work, we propose uncertainty estimation for the analytical results that are obtained from determination of cadmium, lead, copper, iron, manganese and nickel in human hair by flame and electrothermal atomic absorption spectrometry （FAAS and ETAAS）. To estimate the uncertainty of analytical result obtained, two types of bias are calculated in the assessment of trueness： a proportional bias and a constant bias. Nested design was applied for calculating proportional bias and Youden method to calculate the constant bias. The results we obtained for proportional bias are calculated from spiked samples. In this case, the concentration found is plotted against the concentration added and the slop of standard addition curve is an estimate of the method recovery. Estimated method of average recovery in human hair is： （1.019 ±0.026）, （0.918 ±0.014）, （1.073±0.016）, （1.0597± 0.017）, （1.073± 0.020） and （0.934± 0.117） for Cd, Pb, Mn, Ni, Fe and Cu respectively.