微型氢化物发生-原子吸收光谱法测定纺织品中的痕量砷和锑

采用三毛细管微型在线氢化发生技术和装置, 建立了氢化物发生-电热石英管原子吸收法测定纺织品中痕量As、 Sb的分析方法. 研究了共存离子对As、 Sb检测的干扰及消除方法. 结果表明: 该方法除Co、 Sn对As和Ni对Sb有干扰外, 其它干扰元素允许量都较大. 采用酒石酸和KI混合掩蔽剂可抑制Co、 Sn对As和Ni对 Sb的干扰. As和Sb的检出限分别为0.7和0.4 ng/L, 已用于测定纺织品中痕量As和Sb的分析.     

氢化物发生-原子荧光光谱法同时测定高纯铟中As、Sb

研究了氢化物发生-原子荧光光谱法测定高纯铟中微量As、Sb元素的条件,选择了适宜的反应条件以及仪器的最佳工作条件,考察了铟基体对被测元素的干扰,采用基体匹配的方法消除干扰,建立了氢化物发生-原子荧光光谱法测定高纯铟中微量的As、Sb的分析方法。As、Sb的检出限分别为0.18和0.28 ng/mL,测定下限为1.2×10-5和1.9×10-5,相对标准偏差分别为1.9%和1.7%,回收率为97.4%和103%,适用于5～6 N高纯铟中微量As、Sb的测定。     

Derivative hydride generation atomic absorption spectrometry and determination of lead traces in waters

Fundamentals of derivative hydride-generation atomic absorption spectrometry (DHGAAS) are described. A linear relationship was obtained between the derivative absorbance and the concentration of analysis in a sample. The new DHGAAS method was applied to the determination of traces of lead in water. The conditions affecting the derivative absorbance of lead were evaluated and optimized. The detection limit and sensitivity of the proposed method were 26 times and 8.8 times better, respectively, than those of conventional hydride-genera-tion atomic absorption spectrometry. The characteristic concentration (for a derivative absorbance of 0.0044) and detection limit (3sigma) for lead were 0.017 and 0.096 ng mL(-1), respectively, for a 2 mV min(-1) sensitivity range setting. The recovery range was 92.5-103%.     

氢化物发生-双道原子荧光光谱法同时测定钢中砷和锑

建立了一种氢化物发生双道原子荧光光谱法同时测定钢中痕量砷和锑的方法．对实验条件进行了优化,在最佳工作条件下,砷和锑的检出限分别为0．012ng／g和0．034ng／g,RSD分别为1．24％和1．97％．将本法应用于钢中的砷和锑的测定,采用加标回收实验控制方法的准确性,砷的回收率为96％～98％,锑的回收率98％～102％．     

氢化物发生电加热石英管原子吸收法测定包头铁矿中的砷、锑、铋

研究了氢化物发生原子吸收法测定包头矿中痕量砷、锑、铋的分析方法,试验确立了反应条件,建立了以KI、抗坏血酸、硫脲为还原体系,消除试样中共存元素的干扰,利用KMnO4消除锑对砷的干扰.砷、锑、铋的检出限可分别达到:0.15,0.28,0.15 ng/mL.方法已用于包头矿分析.     

Determination of inorganic arsenic species As(III) and As(V) by high performance liquid chromatography with hydride generation atomic absorption spectrometry detection

The paper presents the principles and advantages of a technique combining high performance liquid chromatography and hydride generation atomic absorption spectrometry (HPLC-HGAAS) applied to speciation analysis of inorganic species of arsenic As(III) and As(V) in ground water samples. With separation of the arsenic species on an ion-exchange column in the chromatographic system and their detection by the hydride generation atomic absorption spectrometry, the separation of the analytical signals of the arsenic species was excellent at the limits of determination of 1.5 ng/ml As(III) and 2.2 ng/ml As(V) and RSD of 4.3% and 7.8% for the concentration of 25 ng/ml. The hyphenated technique has been applied for determination of arsenic in polluted ground water in the course of the study on migration of micropollutants. For total arsenic concentration two independent methods: HGICP-OES and HGAAS were used for comparison of results of real samples analysis.     

Speciation of major arsenic species in seawater by flow injection hydride generation atomic absorption spectrometry

Arsenic present at 1 microg L(-1) concentrations in seawater can exist as the following species: As(III), As(V), monomethylarsenic, dimethylarsenic and unknown organic compounds. The potential of the continuous flow injection hydride generation technique coupled to atomic absorption spectrometry (AAS) was investigated for the speciation of these major arsenic species in seawater. Two different techniques were used. After hydride generation and collection in a graphite tube coated with iridium, arsenic was determined by AAS. By selecting different experimental hydride generation conditions, it was possible to determine As(III), total arsenic, hydride reactive arsenic and by difference non-hydride reactive arsenic. On the other hand, by cryogenically trapping hydride reactive species on a chromatographic phase, followed by their sequential release and AAS in a heated quartz cell, inorganic As, MMA and DMA could be determined. By combining these two techniques, an experimental protocol for the speciation of As(III), As(V), MMA, DMA and nonhydride reactive arsenic species in seawater was proposed. The method was applied to seawater sampled at a Mediterranean site and at an Atlantic coastal site. Evidence for the biotransformation of arsenic in seawater was clearly shown.     

HG-AAS法测定不锈钢食具浸泡液中的砷

研究了利用氢化物发生原子吸收法测定不锈钢食具浸泡液中痕量砷的反应体系.对载气流速、硼氢化钠溶液的浓度、5％抗坏血酸-5％硫脲溶液添加量和介质酸度的影响,以及基体和共存离子的干扰等条件进行了研究.样品加标回收率为95.8％～106.2％,测定结果的相对标准偏差不大于2.8％,方法检出限为0.12 μg/L.该方法适用于不...     

Simultaneous determination of arsenic, antimony, selenium and tin by gas phase molecular absorption spectrometry after two step hydride generation and preconcentration in a cold trap system

A cold trap system for the simultaneous determination of arsenic, antimony, selenium and tin by continuous hydride generation and gas phase molecular absorption spectrometry is described. The hydride generation is carried out in two steps; first, tin hydride is generated at low acidity and second, arsenic, antimony and selenium hydrides are formed at higher acidity. All the hydrides are collected in a liquid nitrogen cryogenic trap and transported to the flow cell of a diode array spectrophotometer, where molecular absorption spectra are obtained in the 190-250 nm range. Five calibration solutions containing arsenic, antimony, selenium and tin are solved using multiple linear regression analysis. Tests are performed in order to extend the same manifold to other hydrides but no signals are obtained for bismuth, cadmium, lead, tellurium and germanium. Under the optimum conditions found and using the wavelengths of maximum sensitivity (190, 198, 220 and 194 nm), the analytical characteristics of each element are calculated. The detection limits are 0.050, 0.020, 0.12 and 1.1 mug ml(-1) and the RSD values are 3.7, 3.1, 3.5 and 3.0% for As, Sb, Se and Sn, respectively. The method is applied to As, Sb, Se and Sn determination in natural spiked water samples.     

Speciation of arsenic in water samples by high-performance liquid chromatography-hydride generation-atomic absorption spectrometry at trace levels using a post-column reaction system

Anion-exchange HPLC has been combined with hydride generation - atomic absorption spectrometry (HG-AAS) for the routine speciation of arsenite, arsenate, monomethylarsenic acid and dimethylarsinic acid. The sensitivity of the AAS-detection was increased by a post-column reaction system to achieve complete formation of volatile arsines from the methylated species and arsenate. The system allows the quantitative determination of 0.5 microg/l of each arsenic compound in water samples. The stability of synthetical and natural water containing arsenic at trace levels was investigated. To preserve stored water samples, a method for quantitative separation of arsenate at high pH-values with the basic anion-exchange resin Dowex 1x8 was developed.     

氢化物原子光谱法的新增效试剂L-半胱氨酸

介绍L-半胱氨酸在氢化物原子光谱法中的预还原、增敏和去干扰等作用。综述了L-半胱氨酸作为氢化物原子光谱法的新增效试剂在测定砷、锑、铋、锡、锗等元素及砷各种形态时的应用。引用文献38篇。     

Inter-element interferences in the determination of arsenic and antimony by hydride generation atomic absorption spectrometry with a quartz tube atomizer

The interferences between arsenic and antimony on each other during the hydride generation atomic absorption spectrometry (HGAAS) determination of arsenic and antimony using a quartz tube atomizer (QTA) were examined. In order to eliminate or reduce such interferences by selective heat decomposition of arsine and stibine, a Pyrex adsorption U-tube trap containing glass wool was placed between the drying tube and the quartz tube atomizer. Although at 250 °C stibine decomposes and is held almost completely by the trap, arsine is also decomposed to an extent of 24% and, therefore, thermal decomposition is not useful to eliminate antimony interference on arsenic determination. The effect of coating the glass wool in the U-tube with antimony on the arsenic suppression of the antimony signal was studied. The results showed that the antimony coating in the U-tube could not hold arsenic effectively and its interference on the antimony signal could not be eliminated by this means. In the second part of the study, oxygen was supplied to the quartz tube atomizer during atomization in order to study the effect of supplying oxygen on the antimony signal and on the interference of arsenic in the antimony determination. Sensitivity was increased in the presence of oxygen and interferences of arsenic on antimony determination was decreased by about 10% when oxygen was supplied. It was also observed that the extent of interferences depended mainly on the interferent concentration rather than the analyte concentration.     

氢化物发生-原子荧光光谱法同时测定水中砷和锑

建立在硝酸介质中用氢化物发生-原子荧光光谱法同时测定水中砷和锑的方法。优化了仪器工作条件、酸度、硼氢化钾及还原剂浓度。砷、锑的线性范围为0～10．0μg／L;检出限分别为0．02,0．01μg／L;测定结果的相对标准偏差分别为1．77％～3．72％,2．95％～4．87％（n=6）;加标回收率分别为98％106％,96％105％。该法操作简便,灵敏度高,快速,便于推广,适用于水中砷和锑的同时测定。     

A FIA-system for As(III)/As(V)-determination with electrochemical hydride generation and AAS-detection

A flow-injection system with electrochemical hydride generation and atomic absorption detection for As(III)/As(V) determination is described. A simple electrolytic flow-through cell has been developed and optimized. Several cathode materials like Pt, Ag, Cu, C and Pb have been tested. The influence of the electrolysis current, concentration of sulfuric acid, carrier stream, flow rate, sample volume and interferences by other metals on the arsenichydride generation have been studied. For the determination of total inorganic arsenic, As(V) is reduced to As(III) on-line by postassium iodide or L-cysteine at 95 degrees C. The influence of the temperature and the reduction medium on this pre-reduction step has been tested. The calibration curve is linear in the range of 5 to 50 microg/L for As(III) and total inorganic arsenic and shows a higher sensitivity than in case of reduction with sodium tetrahydroborate. The detection limit is 0.4 microg/L for As(III) and 0.5 microg/L for total inorganic arsenic at a sample volume of 1 mL.     

Determination of total arsenic in serum and packed cellsof patients with renal insufficiency

In order to investigate the arsenic level in serum and packed cells of patients with renal insufficiency, total arsenic (As) concentrations were determined with hydride generation atomic absorption spectrometry (HGAAS) in serum (S) and packed cells (PC) of 31 non-dialyzed patients. The accuracy of the method was tested by the analysis of arsenic in 3 certified reference materials. Patients showed a three-fold increase of arsenic concentrations in serum and a two-fold increase of arsenic in packed cells compared with controls. Patients (n=10) with higher serum creatinine (>2.0 mg/dL), urea (>0.70 g/L) and urinary protein (mean+/-SD: 1.12+/-0.82 g/L) showed higher arsenic concentrations (5.8+/-3.3 microg/L in serum and 18.0+/-16.7 microg/kg in packed cells) compared with those with lower creatinine (<1.6 mg/dL), urea (<0.6 g/L) and urinary protein (mean+/-SD: 0.27+/-0.82 g/L) (n=16, serum arsenic 1.2+/-1.2 microg/L, packed cells arsenic 2.6+/-1.9 microg/kg). The significant differences (both p < 0.001) in S and PC-arsenic levels of patients in group I and II implies a relationship between the arsenic level and the degree of chronic renal insufficiency.     

Determination of major antimony species in seawater by continuous flow injection hydride generation atomic absorption spectrometry

The capabilities and limitations of the continuous flow injection hydride generation technique, coupled to atomic absorption spectrometry, for the speciation of major antimony species in seawater, were investigated. Two pre-concentration techniques were examined. After continuous flow injection hydride generation and collection onto a graphite tube coated with iridium, antimony was determined by graphite furnace atomic absorption spectrometry. The low detection limits obtained (∼5 ng l⁻¹ for Sb(III) and ∼10 ng l⁻¹ for Sb(V) for 2.5 ml seawater samples) permitted the determination of Sb(III) and total antimony in seawater with the use of selective hydride generation and on-line UV photooxidation. The number of samples that can be analyzed is about 15 per hour for Sb(III) determinations and 10 per hour for total antimony determinations. The analysis of seawater samples showed that Sb(V) was the predominant species, even in the presence of important biological activity.     

Arsenic determination in certifiable color additives by dry ashing followed by hydride generation atomic absorption spectrometry

The preparations of digested samples of certifiable color additives by dry ashing and wet digestion for arsenic analysis by hydride generation atomic absorption spectrometry (AAS) were compared. The dry ashing technique was based on the preparation used in ASTM D4606-86 for determination of As and Se in coal. The acid digestion method used nitric and sulfuric acids heated by microwaves in sealed vessels. The digested color additives were analyzed for As by using hydride generated from sodium borohydride mixed with the acidified solution on a flow injection system leading to an atomic absorption spectrometer. Dry ashing was preferable to wet digestion because wet digestion yielded poor recoveries of added As. Dry ashing followed by hydride generation AAS gave determination limits of 0.5 ppm As in the color additives. At a specification level of 3 ppm As, the precision of the method using dry ashing was +/- 0.4 ppm (95% confidence interval).     

Sequential determination of tin, arsenic, bismuth and antimony in marine sediment material by inductively coupled plasma atomic emission spectrometry using a small concentric hydride generator and L-cysteine as prereductant

A hydride generation system using a small concentric hydride generator combined with inductively coupled plasma atomic emission spectrometry (ICP-AES) was established to determine tin, arsenic, bismuth and antimony in a marine sediment material with L-cysteine as a pre-reductant. Influences of concentrations of three kinds of acids (HCl, HNO₃ and HClO₄), L-cysteine, and sodium tetrahydroborate(III) as well as sodium hydroxide were investigated. The interferences from transition ions were found to be insignificant for determination of the four elements in presence of L-cysteine. Under optimized conditions the detection limits were 0.6 ng/mL for arsenic(III), 0.8 ng/mL for antimony(III), 1.7 ng/mL for tin(IV), and 1.2 ng/mL for bismuth(III). The method was applied to determine the four elements in standard marine sediment materials and the results were in agreement with certified values.     

Elimination of hydrofluoric acid interference in the determination of antimony by the hydride generation technique

For the determination of antimony by hydride generation techniques a pretreatment procedure has been developed for the reduction of Sb(V) to Sb(III) in order to remove the effect of hydrofluoric acid which strongly interferes with the reduction of pentavalent antimony to the trivalent state. It is based on the combined action of l-cysteine and boric acid at 80 degrees C. The pretreatment is effective in both nitric and hydrochloric acid media. Quantitative recoveries are obtained in less than 60 min. Under these conditions antimony is reduced to the trivalent state in acid media containing both nitric and hydrochloric acid. The method has been applied to the determination of total antimony in certified reference materials of sediments after pressurized microwave digestion with HNO(3)-HCl-HF. Good agreement is obtained by using both analytical techniques: continuous flow hydride generation atomic fluorescence spectrometry and flow injection electrothermal atomic absorption spectrometry with in-situ trapping of stibine in a graphite atomizer.     

Optimization and validation of arsenic determination in foods by hydride generation flame atomic absorption spectrometry

A hydride generation flame atomic absorption spectrometric method was developed and optimized to quantitate arsenic (As) in foods. A wet digestion of the samples with HNO3 + H2O2 was performed and excess oxidants were eliminated by addition of hydrochloric acid and urea. As5+ in As3+ was then reduced by potassium iodide. The As3+ solution was analyzed by generation of arsine with sodium tetrahydroborate. As determination ranged from 2.5 to 20 microg/L, with a determination coefficient of 0.997. The limits of detection (LOD) and quantitation (LOQ) were 0.6 and 2.1 microg/L, respectively. The method was validated and good results were obtained for recovery, precision, accuracy, LOD, and LOQ. This method is now used to analyze foods from Rwanda.