电热原子吸收分析中的固体进样技术

本文综述了电热原子吸收分析中固体进样技术的进展,详细讨论了固体直接进样和悬浮体进样和样品制备方法、进样工具、校正曲线、基体改进技术、分析性能及其最新应用。     

Heated Slurry Sampling for the Determination of Cadmium in Food by Electrothermal Atomic Absorption Spectrometry

A heating procedure is reported with slurry sampling electrothermal atomic absorption spectrometry to improve the accuracy of cadmium determination in food. In comparison to conventional slurry sampling, the heating significantly increased cadmium recovery and improved the precision. For the optimized procedure, 25–250 mg of food were treated with 2% HNO₃ and 1% H₂O₂ with heating at 120°C for 20 min, followed by the addition of 50 µL of 10% Triton X-100, and homogenization in an ultrasonic bath prior to analysis. Tungsten and rhodium were employed as a permanent modifier with optimum pyrolysis and atomization temperatures of 500°C and 1500°C. Calibration with aqueous standards resulted in good agreement between certified or information values and measured results at the 95% confidence level. A characteristic mass of 0.8 ± 0.1 pg and a detection limit of 0.7 ng g^?1 for a 2% slurry were obtained. The method was employed for the direct determination of cadmium in food certified reference materials.     

Fast Detection of Cadmium in Chocolate by Solid Sampling Electrothermal Vaporization Atomic Absorption Spectrometry and Its Application on Dietary Exposure Risk Assessment

In this work, a rapid detection method using solid sampling electrothermal vaporization atomic absorption spectrometry (SS-ETV-AAS) was established for cadmium in chocolate. The instrumental system includes a solid sampling ETV unit, a catalytic pyrolysis furnace, an AAS detector, and a gas supply system with only an air pump and a hydrogen generator. Herein, MgO material with 1.0–1.5 mm particle size was first employed to replace the kaolin filler previously used to further shorten the peak width and to thereby improve the sensitivity. With 350 mL/min of air, a chocolate sample was heated for 25 s from 435 to 464 °C to remove water and organic matrices; then, after supplying 240 mL/min hydrogen and turning down air to 120 mL/min, a N₂/H₂ mixture gas was formed to accelerate Cd vaporization from chocolate residue under 465 to 765 °C. Under the optimized conditions, the detection limit (LOD) was obviously lowered to 70 pg/g (vs. previous 150 pg/g) with R² > 0.999; the relative standard deviations (RSD) of repeated measurements for real chocolate samples ranged from 1.5% to 6.4%, indicating a favorable precision; and the Cd recoveries were in the range of 93–107%, proving a satisfied accuracy. Thus, the total analysis time is less than 3 min without the sample digestion process. Thereafter, 78 chocolate samples with different brands from 9 producing countries in China market were collected and measured by this proposed method. Based on the measured Cd concentrations, a dietary exposure assessment was performed for Chinese residents, and the target hazard quotient (THQ) values are all less than 1, proving no significant health risk from intaking chocolate cadmium for Chinese residents.     

Determination of Antimony in Sediments by Zeeman-Corrected Electrothermal Atomic Absorption Spectrometry with Ultrasonic Slurry Sampling

A method was developed for the determination of antimony in slurried sediments (on the basis of samples of three Certified Reference Materials) by electrothermal atomic absorption spectrometry (ETAAS) with Zeeman-effect background correction. Slurried samples were prepared in 6% nitric acid containing 0.02% of Triton X-100. A mixed palladium/magnesium chemical matrix modifier, L'vov platform atomization and a temperature-time program with a relatively short (10 s) sample pyrolysis stage were used. The results of the determinations by this technique are in very close agreement with certified values and the repeatability of this analytical procedure expressed in terms of relative standard deviation was typically better than 9% at the slurry concentration of approx. 90 mg/2 mL. The characteristic mass of Sb (at the spectral line 231.1 nm) was 25.6 pg and the limit of detection (calculated for 100 mg/2 mL slurry) was about 0. 04 μg/g.     

Determination of Bismuth in Sediment and Soil by Ultrasonic Slurry Sampling Electrothermal Atomic Absorption Spectrometry

The analytical conditions of the direct determination of bismuth in some certified reference material samples (soil and sediment) by slurry sampling Zeeman electrothermal atomic absorption spectrometry (ETAAS) with the use of automated ultrasonic slurry mixing are discussed. Palladium nitrate was used as a chemical modifier. With the use of this modifier it was possible to stabilize bismuth to the pyrolysis temperature of 1300 °C. Platform atomization was performed at 2050 °C. The results of determination are calculated from a simple, aqueous standards based calibration graph. Statistical evaluation of the results indicate that the slurry sampling method is reproducible and the accuracy of the proposed method is very good. This method is rather simple and its other advantages are good sensitivity and relatively short analysis time.     

电热蒸发进样微波诱导等离子体原子吸收光谱法测定银和镉的研究

研究了以常压低功率氩微波诱导等离子体（ＭＩＰ）为原子化器的原子吸收光谱法（ＡＡＳ）测定银和镉。采用电热蒸发（ＥＴＶ）,浓Ｈ２ＳＯ４吸收去溶的进样方法。考察了微波前向功率,载气流量,去溶电压,去溶时间,蒸发电压,酸度对银,镉测定的影响。方法已用于试样分析。     

原子荧光光谱法测定食品中的镉

研究了在水溶液中，Ｃｄ与ＫＢＨ４反应生成挥发性物种，以原子荧光光谱法测定食品中的痕量Ｃｄ的分析方法，方法的检出限为０．１２μｇ／Ｌ，线性范围０～５０μｇ／Ｌ，回收率为８６％～１１２％。     

Cadmium Determination in Human Whole Blood by Electrothermal Atomic Absorption Spectrometry with Magnesium Chloride and Sodium Hydroxide as a Combined Chemical Modifier

In this work, we propose a method to determine trace amounts of Cd in human whole blood samples by electrothermal atomic absorption spectrometry (ETAAS) with the combined chemical modifier including magnesium chloride and sodium hydroxide. Prior to the ETAAS analysis, dissolution of the blood samples is accomplished using a HNO₃-HClO₄double closed-vessel microwave digestion technique followed by drying of the dissolved blood samples by means of an infrared lamp. In using this approach, a MgCl₂ chemical modifier is added to the digested samples, then they are injected into the graphite furnace for detecting the Cd level via atomic absorption spectrometer. Besides we used a NaOH chemical modifier, which removed the matrix major elements through prior ashing at 1200 ° C for 30 s, and the Cd is subsequently volatilized at 2200 °C and determined by AAS. However, the proposed method can be employed to determine the of Cd level in whole blood samples by the calibration technique and the standard-additions method. Its validity is confirmed with two certified reference whole blood materials (Seronorm Trace Elements Whole Blood Batch no. 205052 and Batch no. 203056). By using 10 μL injections, a detection limit of 0.052 ng mL^?1 is achieved.     

钨丝在原子吸收光谱分析中的应用

随着原子化器和检测器的小型化，钨丝原子吸收光谱分析仪在便携式分析仪器方面显示了很大的潜力。本文主要评述了近年来钨丝在电热原子吸收光谱分析中的应用，引用文献49篇。     

螯合树脂静态富集／电热蒸发（ETV）—ICP—AES测定铂族元素Pt,Pd和Os

用含氮，硫功能团的螯合树脂ＹＰＡ，进行静态吸附，含待测定元素的浓缩物制成悬浮体，采用悬浮体进样／电热蒸发等离子体原子发射光谱（ＥＴＶ－ＩＣＰ－ＡＥＳ）直接测定。方法的检出限分别为０．５，０．７和４．０ｎｇ／ｍＬ（对Ｐｔ，Ｐｄ和Ｏｓ）相对标准偏差分别为２．６％，４．７％和３．８％（ｎ＝１０，Ｐｔ：２．０ｍｇ／Ｌ，Ｐｄ：２ｍｇ／Ｌ，Ｏｓ：５．０ｍｇ／Ｌ）。应用本法对质标样进行了分析，测定值与标准值基本     

Determination of Rhodium in Biological Materials by Electrothermal Atomic Absorption Spectrometry with a Tungsten Tube Atomizer

Abstract

Electrothermal atomic absorption spectrometry (ETAAS) of rhodium with a tungsten tube atomizer has been investigated under optimum conditions (atomization temperature; 2230 C, purge gas; Ar 480 ml min^?1 + H₂ 20 ml min^?1, and pyrolysis temperature; 590 C). The absolute characteristic mass (the mass of element giving 0.0044 abs.) of rhodium by the atomizer was 86.5 pg and the detection limit was 16.5 ng ml^?1 (3S/N). The interferences caused by large amounts of interferents were evaluated. Al, Ca, Cu, Fe, K, Mg, Na, Pb and Zn severely interfered in the AA signal of rhodium. Ammonium phosphate, ascorbic acid, palladium nitrate, copper nitrate, lanthanum nitrate, thiocyanate and thiourea, well known as matrix modifiers were tested to eliminate the severe interferences. However, by the addition of these compounds, the rhodium signal was not recovered. The standard addition method was adapted for the determination of rhodium in biological materials. The recovery of spiked-rhodium in biological materials was in the range of 97.4 to 107%.     

电化学微流池富集-电热原子吸收法测定海水中(超)痕量镉

建立了电化学微流池与电热原子吸收光谱联用技术对(超)痕量镉进行测定的方法。利用自制电化学微流池对(超)痕量镉富集,后经反向电压和酸液洗脱,洗脱液由电热原子吸收光谱仪进行测定。优化了测定条件,实验结果表明,在0.05~0.80μg/L范围内成线性关系,相关系数为0.9912,检出限(3σ)达到0.004μg/L,富集倍率为11。将该方法应用到海水中(超)痕量镉的测定,相对标准偏差在2.2%~3.4%(n=3),回收率在86.0%~95.5%。     

Determination of Manganese in Sludge,Alloy, and Soil by Tungsten Coil Atomic Emission Spectrometry

A tungsten coil atomic emission spectrometer (WCAES) was developed and evaluated for the determination of manganese in industrial sludge, alloy, and soil. The system employed a coil extracted from a 150 watts/15 volts commercial slide projector light bulb and a simple power supply that provided a constant current to the coil. The analytical signals were resolved and detected using a Czerny-Turner spectrometer and a charge coupled device. Three manganese emission lines were detected simultaneously. Using different emission lines, limits of detection for manganese varied from 0.54 to 0.65 milligram per liter, and relative standard deviations for manganese at 5 milligrams per liter varied from 5.9 to 8.5 percent (n = 10). Summation of the Mn signals improved the detection limit to 0.17 milligram per liter and decreased the relative standard deviation to 1.7 percent. Spectral interferences were observed in the presence of Al, Ca, K, and Na. The accuracy was determined using two certified reference materials, and the results obtained by WCAES were in agreement with those obtained by inductively coupled plasma-optical emission spectrometry at the 95 percent confidence level.     

氟化电热蒸发（ETV）－ICP－AES直接测定生物试样中不同挥发性元素的比较研究

本文以聚四氟乙烯（ＰＴＥＥ）悬浮体为氟化剂，对悬浮体制样ＥＴＶ－ＩＣＰ－ＡＥＳ直接测定生物试样中不同挥发性元素锡、铜和镉的蒸发行为，影响因素及分析性能进行了比较研究，得出了相应的规律性。在选定实验条件下，本法测定ＭＯ，Ｃｕ和Ｃｄ的检出限分别为０．４３、４．２和１４１ｎｇ／ｍＬ，ＲＳＤ分别为３．８％、４．２％和２．２％。提出的方法已应用于ＣＲＭ２８１生物标样分析，结果与参考值吻合。     

Determination of Cd,Pb and Sr by Microwave Plasma Torch Atomic Emision Spectrometry Using an Electrothermal Vaporization Sample Introduction System

ＩｎｔｒｏｄｕｃｔｉｏｎＥｌｅｔｒｏｔｈｅｒｍａｌｖａｐｏｒｉｚａｔｉｏｎ（ＥＴＶ）ａｓａｍｅａｎｓｏｆｓａｍｐｌｅｉｎｔｒｏｄｕｃｔｉｏｎｉｎｍｉｃｒｏｗａｖｅｉｎ－ｄｕｃｅｄｐｌａｓｍａ（ＭＩＰ）ｓｏｕｒｃｅｓｐｅｃｔｒｏｍｅｔｒｙｈａｓｂｅｅｎ...     

氢化物发生-原子荧光光谱法测定牡蛎中的镉

利用HNO3–HClO4混合酸消解样品,采用氢化物发生–原子荧光光谱法测定牡蛎中镉的含量。在优化的仪器工作条件下,镉的质量浓度在0.20～1.50μg/L范围内与荧光强度呈良好的线性关系,线性相关系数为0.9992,检出限为0.10μg/L,测定结果的相对标准偏差为4.48%(n=12),加标回收率为94.3%～106.1%。测定了标准物质贻贝GB 08571中镉的含量,测定结果与标准值一致。该方法可满足牡蛎中微量镉的分析测定。     

聚三氟氯乙烯化学改进剂在电热蒸发(ETV)-ICP-AES直接测定生物试样中微量钛的应用

本文首次提出以聚三氟氯乙烯（ＰＴＦＣＥ）为化学改进剂，应用于悬浮体制样ＥＴＶ－ＩＣＰ－ＡＥＳ直接测定固体生物试样中微量钛。实验采用５％ＰＴＦＣＥ，促进Ｔｉ的蒸发。方法的绝对检出限为２ｐｇ（按５σ计），ＲＳＤ为２．６％（ｎ＝５）。该法用于直接测定ＧＢＷ０８５０５茶叶粉末样品中的Ｔｉ，结果与参考值吻合，回收率为９７．３～１０５．４％。     

Determination of Mercury and Thallium in Seawater by Electrothermal Vaporization Inductively Coupled Plasma Mass Spectrometry

Electrothermal vaporization inductively coupled plasma mass spectrometry (ETV‐ICP‐MS) has been applied to the determination of Hg and Tl in seawater samples. Various modifiers were tested for the best signal of these elements. After preliminary studies, 0.3% EDTA, 0.1%m/vTAC and 1% v/v HCl were added to the sample solution to work as the modifier. Since the sensitivities of Hg and Tl in various seawater matrices and aqueous standard solutions were quite different, standard addition method and isotope dilution method were used for the determination of Hg and Tl in these seawater samples. This method was applied to the determination of Hg and Tl in NASS‐4 and CASS‐3 reference seawater samples and seawater samples collected from the Kaohsiung area. Results obtained by isotope dilution method and method of standard additions agreed satisfactorily. Detection limits were in the range of 5‐15 and 0.4‐0.5 ng l^?1 for Hg and Tl in seawater, respectively, with the ETV‐ICP‐MS method. The precision between sample replicates was better than 18%) for all the determinations.     

固体直接进样石墨炉原子吸收法测定土壤中镉元素

固体直接进样是近年来石墨炉原子吸收分析领域发展较快的技术,它取代了繁冗的对固体样品的前处理,避免了样品的污染和损失,也保护了操作人员的身体健康。采用固体直接进样-石墨炉原子吸收光谱仪,结合使用持久化学改进剂对环境土壤样品中Cd元素进行测定,其结果表明,方法检出限为0.002 66ng,定量测定下限为0.008 87ng,相对标准偏差RSD≤10%,方法准确、可靠,均满足环境土壤测试方法的要求。