原子吸收光谱法测定苦藠中微量元素的含量

苦藠别名小野蒜是食用地下鳞茎及嫩茎叶的野生蔬菜,属药食同源的百合科多年生草本植物.有温中散结,宽胸通阳,祛湿止痢作用~([1,2]).在食疗方面有:(1)降脂作用,且性味辛温,能温阳散结,可用来治疗高胆固醇和高血脂症.(2)降低血压的奇妙作用,常食有通阳气、宽胸的效果.     

火焰原子吸收光谱法测定茯苓中微量元素

本文确定了各微量元素火焰原子吸收光谱仪的工作条件,建立了各微量元素线性回归方程.应用火焰原子吸收光谱法测定了天然茯苓和液体发酵茯苓中微量元素含量.研究结果表明二者微量元素含量存在一定的差异,探讨了产生上述差异的原因.     

火焰原子吸收光谱法测定软儿梨中微量元素

采用火焰原子吸收光谱法测定了软儿梨果肉和果汁中K、Mg、Fe、Ca、Mn、Cu、Zn的含量.样品以HNO3-HClO4消解,对消解和仪器测定条件进行了优化选择,建立了相应的原子吸收光谱测定方法.方法的RSD在1.0%～3.0%之间,加标回收率在90%～100%之间.     

火焰原子吸收法测定鸡尾木中无机元素的含量

鸡尾木(ExcoecariaVenenataS.LeeetF.N.Wei)属大戟科,海漆属,为民间药用珍贵植物,用于治疗牛皮癣、慢性湿疹等,疗效颇佳[1]。鸡尾木中无机元素,尤其是医学微量元素的测定对其药理效的研究有重要的参考价值。1　实验部分1 1　仪器及试剂TAS 986原子吸收分光光度计(北京普析通用仪器有限责任公司);空心阴极灯:Fe、Cu、Ni、Cr、Cd、Zn、Co、Ba、Ca(北京瑞利普光电器厂);Mg、Pb(北京真空电子技术总公司);Mn(北京市朝阳天宫电器厂);AdventurerTM电子天平(奥豪斯国际贸易〈上海〉有限公司)。标准储备液:配制Zn2+、Mg2+、Fe3+、Mn2…     

Determination of trace elements in automotive fuels by filter furnace atomic absorption spectrometry

The determination of Cd, Cr, Cu, Pb and Ni was performed in gasoline and diesel fuel samples by electrothermal atomic absorption spectrometry using the Transverse Heated Filter Atomizer (THFA). Thermal conditions were experimentally defined for the investigated elements. The elements were analyzed without addition of chemical modifiers, using organometallic standards for the calibration. Forty-microliter samples were injected into the THFA. Gasoline samples were analyzed directly, while diesel fuel samples were diluted 1:4 with n-heptane. The following characteristic masses were obtained: 0.8 pg Cd, 6.4 pg Cr, 12 pg Cu, 17 pg Pb and 27 pg Ni. The limits of determination for gasoline samples were 0.13 μg/kg Cd, 0.4 μg/kg Cr, 0.9 μg/kg Cu, 1.5 μg/kg Pb and 2.5 μg/kg Ni. The corresponding limit of determination for diesel fuel samples was approximately four times higher for all elements. The element recovery was performed using the addition of organometallic compounds to gasoline and diesel fuel samples and was between 85 and 105% for all elements investigated.     

Determination of trace elements in gallium arsenide by graphite-furnace atomic absorption spectrometry after pretreatment in gas streams

Atomic absorption spectrometry (AAS) with a resistively-heated graphite furnace is used for the determination of chromium (0.3–1 atom/10⁶ atom) in chromium-doped gallium arsenide after pretreatment in a separate furnace in a stream of argon to remove arsenic, and of manganese and silver (0.03 and 0.04 atom/10⁶ atoms, respectively) by a similar procedure after pretreatment with argon and chlorine, the latter to remove both gallium and arsenic as volatile chlorides. Results for chromium were in agreement with those obtained by furnace AAS after dissolution and by spark-source mass spectrometry (SSMS) but AAS after dissolution is more precise. Results for manganese and silver obtained by both gas pretreatments were in good agreement, but were higher than those obtained for presparked material by SSMS, indicating that surface contamination of gallium arsenide was not completely removed by the etching methods used. The procedures established that the concentrations of bismuth, indium and lead in the gallium arsenide sample were below the limits of detection of 3 × 10^?3, 10 × 10^?3 and 1 × 10^?3 atom/10⁶ atoms, respectively. In all cases, calibration graphs were constructed from data obtained with aqueous solutions of appropriate salts.     

Determination of trace elements in sea water by graphite-furnace atomic absorption spectrometry after preconcentration by tetrahydroborate reductive precipitation

A method is described for the preconcentration of 16 elements from coastal and deep ocean sea water based on their reductive precipitation by sodium tetrahydroborate. The enrichment factors obtained were sufficient to permit the analysis of a near-shore sea-water reference material (11 elements) and an open ocean sea-water reference material (9 elements). Recoveries from 900 ml of sea water ranged from 80 to 107% (100-ml sample for Mn) with absolute blanks between <1.0 ng (Se) and 20 ng (Cu). Estimated detection limits varied from 0.3 ng l ^?1 (Pb) to 19 ng l^?1 (As) based on a 36-fold concentration of a 900-ml sample.     

Determination of lead in blood by tungsten coil electrothermal atomic absorption spectrometry

A method for the determination of lead in blood using a tungsten coil atomizer is described. A 100 μl volume of the whole blood sample is transferred to a sampler cup containing 100 μl of water plus 300 μl of 0.25% v/v Triton X-100. After lysis of blood cells, 500 μl of 10% w/v trichloroacetic acid is added for protein precipitation and 10 μl of the supernatant solution is automatically delivered into the tungsten coil. The furnace heating program is implemented in 41 s. It is shown by the paired t-test that there is no significant difference at the 5% probability level between results obtained by the proposed method and by using a transversely heated graphite atomizer with a longitudinal Zeeman background correction. Accuracy is also assessed by employing reference materials. The proposed tungsten coil procedure presents a characteristic mass of 15 pg Pb and a detection limit of 1.9 μg Pb dl⁻¹.     

微波消解-原子吸收光谱法测定蚕蛹中的微量元素

分别采用FAAS和GFAAS方法,测定蚕蛹样品中的常见微量元素及有害重金属元素。对微波消解条件和测定方法进行了探讨和优化,并用标准物质贻贝验证,获得较满意的准确度和精密度。方法可用于蚕蛹样品及同类产品的微量元素元素测定。     

Determination of aluminium in blood plasma or serum by electrothermal atomic absorption spectrometry

A carbon-furnace atomic absorption method is used to determine aluminium in blood serum or plasma, diluted (1 + 2) with purified water prior to injection (20 μl) into the furnace. Procedures are described to reduce contamination during sample collection, storage and preparation of samples. A study of the interferences of inorganic ions shows that the temperature programme developed minimises these, allowing the use of aqueous standards for calibration. Ashing at 1400°C, prior to atomisation, also removes non-specific background effects, and optical correction is not required. A sample throughput of 50 duplicate analyses per day is possible and the precision (between batch) at 24 μg Al l^-1 was 11.2% (n = 10) and at 340 μg Al l^-1 was 6.3% (n = 18). Down to 4 μg Al l^-1 can be determined. Reference values for a healthy population were 4.1–20 μg Al l^-1 (mean 10.2).     

Determination of thallium by furnace atomic absorption spectrometry

The analytical conditions for the determination of thallium by graphite furnace atomic absorption spectrometry were studied and optimized using the peak-height mode. The charring-atomization curves for thallium from different atomization surfaces were constructed and the optimum charring and atomization conditions were established. These atomization surfaces included pyrolytic graphite-, tantalum-, zirconium- and tungsten-coated graphite tubes. The effects of different inorganic acids on the absorbance of thallium from different surfaces were studied. Using tungsten carbide-coated tubes, the interference effects due to hydrochloric and perchloric acids were eliminated. The matrix modification technique was also investigated for increasing the maximum permissible charring temperature for thallium. The matrix modifiers used included tungsten, zirconium, nickel and tantalum. The effect of adding these modifiers were studied in the presence of different acids. Tungsten increased the maximum permissible charring temperature from 400 to 1000 °C.     

Determination of some trace elements in food and soil samples by atomic absorption spectrometry after coprecipitation with holmium hydroxide

The determination of trace elements in food and soil samples by atomic absorption spectrometry was investigated. A coprecipitation procedure with holmium hydroxide was used for separation-preconcentration of trace elements. Trace amounts of copper(II), manganese(II), cobalt(II), nickel(ll), chromium(lll), iron(Ill), cadmium(ll), and lead(ll) ions were coprecipitated with holmium hydroxide in 2.0 M NaOH medium. The optimum conditions for the coprecipitation process were investigated for several commonly tested experimental parameters, such as amount of coprecipitant, effect of standing time, centrifugation rate and time, and sample volume. The precision, based on replicate analysis, was lower than 10% for the analytes. In order to verify the accuracy of the method, the certified reference materials BCR 141 R calcareous loam soil and CRM 025-050 soil were analyzed. The procedure was successfully applied for separation and preconcentration of the investigated ions in various food and soil samples. An amount of the solid samples was decomposed with 15 mL concentrated hydrochloric acid-concentrated nitric acid (3 + 1). The preconcentration procedure was then applied to the final solutions. The concentration of trace elements in samples was determined by atomic absorption spectrometry.     

Determination of lithium in wines by atomic absorption spectrometry

Lithium (10–150 ng ml^?1) in wine is determined by atomic absorption spectrometry by direct nebulization and after digestion with mixed acids. The results of methods are similar. Thirty-four wines from various Spanish provinces are analysed.     

Determination of mercury in industrial materials by atomic absorption spectrometry after thermal volatilisation

The pyrolysis of samples containing copper, lead, iron, sulphur compounds and organic carbon is applied to separate mercury prior to its determination by a.a.s. Amalgamation on gold collectors followed by thermal desorption, or trapping in an absorption solution followed by reduction/aeration were used depending on the mercury content in the materials. Appropriate additives to the samples and filters are used to ensure complete release of mercury and removal of interfering pyrolysis products.     

Determination of trace elements in Antarctic krill samples by inductively coupled atomic emission and graphite furnace atomic absorption spectrometry

Analytical methods were developed for the determination of trace elements in Antarctic krill samples applying inductively coupled plasma atomic emission spectrometry (ICP-AES) and graphite furnace atomic absorption spectrometry (GF-AAS). Cu, Fe, Mn and Zn were determined by ICP-AES, while Cd and Pb by GF-AAS technique. Two microwave assisted digestion procedures were elaborated for the preparation of 0.5-g krill samples using open and closed vessel systems. The efficiency of the digestion processes was checked by measurements of the total organic carbon content of the solutions obtained. The deviations of the analytical data from the certified values and the relative standard deviations of the concentration measurements were lower for all six elements investigated applying the closed vessel digestion system.     

Determination of small amounts of tungsten by atomic absorption spectrometry after extraction separation

Small amounts of tungsten can be determined by atomic absorption spectrometry, after reduction with tin(II) and separation of the thiocyanate complex into methyl isobutyl ketone. The organic phase is aspirated into an acetylene-nitrous oxide flame There are no interferences from 1000-fold amounts of Zr or Cr(III), 200-fold amounts of U or Ti. 100-fold V or 10-fold Mo. Interference from large amounts of iron(III) is avoided by prior reduction. The method was successfully applied to the determination of tungsten in steels and zirconium alloys.