在线流动注射液—液萃取系统在原子吸收光谱法中的研究及应用

本对用于原子吸收光谱分析的在线液－液萃取流路系统进行了研究，采用了一种新型、适用、简便的相分隔器和相分离器，并用该流路系统对矿石、人发中的Ｃｕ（ＦＡＡＳ）以及矿石中痕量Ａｕ进行了测定（ＧＦＡＡＳ）。在水相和有机相的流量比为２５：１，采样频率为２０ｈ＾－１时，用ＦＡＡＳ法测定Ｃｕ的ＲＳＤ为１．９％（ｎ＝１０）、ＤＬ（３σ）为１．０μｇ·Ｌ＾－１；用ＧＦＡＡＳ法测定Ａｕ的ＲＳＤ为４．９％，ｎ＝１０、     

微流量液相色谱在线大体积进样的方法和专用装置

本发明涉及微分离系统的进样方法,具体地说是一种微流量液相色谱在线大体积进样的方法和专用装置。在微流量液相色谱分离系统的流路中,添加多流路分流切换装置,使得系统在进样和分离时,流动相可以从不同流路分流。样品利用在固定相上的保留,实现色谱系统的大体积进样。     

在线流动注射液－液萃取系统在原子吸收光谱法中的研究及应用

本文对用于原子吸收光谱分析的在线液－液萃取流路系统进行了研究，采用了一种新型、适用、简便的相分隔器和相分离器，并用该流路系统对矿石、人发中的Ｃｕ（ＦＡＡＳ）以及矿石中痕量Ａｕ进行了测定（ＧＦＡＡＳ）。在水相和有机相的流量比为２５：１，采样频率为２０ｈ￣（－１）时，用ＦＡＡＳ法测定Ｃｕ的ＲＳＤ为１．９％（ｎ＝１０）、ＤＬ（３σ）为１．０μｇ．Ｌ￣（－１）；用ＧＦＡＡＳ法测定Ａｕ的ＲＳＤ为４．９％，ｎ＝１０、ＤＬ（３σ）为０．０８μｇ．Ｌ￣（－１）　。     

流动注射分析中混合釜体积与进样量的关系

在流路系统和载流速一定且进样体积不大于反应器体积的０．４５倍时，系统混合釜总体积Ｖｍ与进样体积Ｓｖ的关系可表示为：Ｖｍ＝（ａ＋ｂＳｖ）／（１＋Ｓｖ），ａ和ｂ为与实验条件有关的常数。单体积为定值，与进样体积无关，在流路系统和进样体积一定时，混合釜总体积为定值，与载流流速无关。     

流动注射分光光度法测定微量镉的研究

研究了在Ｔｒｉｔｏｎ Ｘ－１００存在下,以二溴羧基苯基氮氨基偶氮苯（ＤＢＫＤＡＡ）为显色剂的流动注射分光光度测定微量镉的新方法。用ｐＨ１０．５的硼砂－氢氧化钠缓冲溶液作栽流,ＤＢＫＤＡＡ和Ｔｒｉｔｏｎ Ｘ－１００的混合液作试剂流,采用双道流路,在５２０ｎｍ波长下检测反应生成的红色配合物。方法的线性范围是０～０．８０μｇ／ｍＬ,进样频率为１８０样次／小时,直接应用于工业废水中微量镉的测定,结果满意。     

超临界流体色谱系统中采用单泵在线添加改性剂

摘要：采用单个注射泵,以并联流路装置,在超临界CO2流体中在线添加甲醇等改性剂,用作填充柱超临界流体色谱的流动相。改性剂的粘度及流路长度显著地影响改性剂体积分数。利用该装置,可以方便地调节流动相的体积分数,改性剂的体积分数稳定且持久,可初步代替双注射泵系统添加改性剂。     

微流路中利用DNA选择性固定蛋白质

报道了一种可控的通过DNA复合物在微流路中杂交固定蛋白质的方法. 微流路系统中的玻璃基底上固定寡聚核苷酸, 其中的层流提供了不同的DNA-蛋白质复合物. DNA的特异性识别可以将蛋白通过表面寻址固定在基底上. 并且在体系中引入了全内反射荧光技术来追踪整个过程. 此方法的特异性和灵敏度均较高, 且蛋白质的固定和去除可重复. 实验结果显示, 同时检测特异性和非特异性的识别, 可以有效提高生物检测的准确性. 这项技术可以提高具有微流路结构的生物传感器装置的检测质量.     

一种在线液—液萃取微型多用分相器的设计和应用：IV.流动注射液— …

设计了在线液－液萃取多用重分布相器及相应流动注射流路系统与ＩＣＰ－ＡＥＳ法联用。具有良好的分析性能，通过对矿石中某些重稀土元素在硝酸介质中被ＴＢＰ萃取的应用研究表明钇，镱，铒的检出限（３σ）分别为６．８ｎｇ／ｍＬ，０．２ｎｇ／ｍＬ和１．５ｎｇ／ｍＬ，精密度（ＲＳＤ％）分别为０．２４，０．４７和１．８，进样频率为２５－３０个／ｈ。     

一种在线液-液萃取微型多用分相器的设计和应用 Ⅳ.流动注射液-液萃取电感耦合等离子体原子发射光谱法测定矿石中稀土元素

设计了在线液－液萃取多用重力分相器及相应流动注射流路系统与ＩＣＰ－ＡＥＳ法联用，具有良好的分析性能．通过对矿石中某些重稀土元素在硝酸介质中被ＴＢＰ萃取的应用研究表明钇、镱、铒的检出限（３σ）分别为：６．８ｎｇ／ｍＬ、０．２ｎｇ／ｍＬ和１．５ｎｇ／ｍＬ．精密度（ＲＳＤ％）分别为０．２４、０．４７和１．８．进样频率为２５～３０个／ｈ．     

连续流动液─液萃取石墨炉原子吸收分析系统的设计及其性能

求文研究了在线液一液萃取石墨炉原子吸收分析技术，设计了一种半自动萃取流路系统及其与石墨炉的接口装置．采用一步萃取操作，比较了直接水相测定和萃取测定ＡＵ和Ｃｄ的结果，表明该流路系统性能较好。在萃取测定中，ＡＵ和Ｃｄ的检出限分别为０．０７７和０．０５５ｎｇ／ｍＬ；精密度为Ａｕ４．１％（５．５ｎｇ／ｍＬ）和Ｃｄ４．９％（０．２５ｎｇ／ｍＬ）标准样品分析结果与推荐值吻合，采样频率为２０—３０／ｈ．     

流动注射分光光度法测定砷的研究

本文采用自行设计制造的氢化物发生及吸收装置,将流动注射技术同氢化物发生分光光度法结合在一起,设计了一种不使用载气的流动注射分析系统并对该系统的测定条件进行了实验研究,实验用HNO_3-AgNO_3-聚乙烯醇-乙醇混合液作吸收液,结果证明该系统具有操作简便,成本低廉,分析速度快(30次/小时),灵敏度高,重现性好及线性范围可调的优点。     

Flow analysis-hydride generation-Fourier transform infrared spectrometry. A new analytical technique for the simultaneous determination of antimony,arsenic and tin

The combination of flow analysis (FA), hydride generation (HG) and Fourier transform infrared (FTIR) spectrometry is proposed as a novel and powerful analytical technique for the individual and simultaneous determination of antimony, arsenic and tin in aqueous samples. The analytes were transformed into the volatile hydride form by on-line reaction with sodium tetrahydroborate in acidic medium. The gaseous analyte hydrides [M(n)H(m), (g)] generated, were transported by means of a carrier gas stream inside the IR gas cell and the corresponding FTIR spectrum was acquired in a continuous mode. The 1893, 1904 and 2115 cm(-1) bands of the SbH3, SnH4, and AsH3 were selected for the determination of antimony, tin and arsenic, respectively. The limit of detection (3sigma) obtained by using a short-path (10 cm) IR gas cell were 0.25, 0.30 and 1.2 mg l(-1) for the determination of antimony, tin and arsenic, respectively; while the precision (relative standard deviation, RSD, n 5) found from a standard solution containing 50 mg l(-1) of each element was, in all cases, less than 0.3%. However, the use of a long-path (7.25 m) IR gas cell improved the figures of merit (sensitivity, limits of detection and quantification) nearly 60-fold. The effect of the main experimental and instrumental variables, such as acidic media, sodium tetraborohydrate concentration, nitrogen flow rate, nominal resolution and the scan accumulation on the analytical signals of the antimony, tin and arsenic hydrides, were studied. Further, the potential of the proposed technique for the simultaneous determination of these elements was tested, analyzing synthetic samples containing different amounts of Sb, Sn and As.     

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.     

原子荧光光谱法测定粗锌中的砷

建立了测定粗锌中砷含量的原子荧光光谱法。粗锌样品经硝酸溶液(1+1)低温溶解完全以后,在盐酸介质中,用抗坏血酸预还原,以硫脲掩蔽铜、铁、银等杂质元素,砷被硼氢化钾还原为氢化物,用氩气导入原子化器测量。砷测定结果的相对标准偏差为1.5%~3.0%(n=11),加标回收率为98.4%~103.6%。与国家标准测定方法分光光度法测定结果对比,相对偏差为0.1%~2.4%。该法准确、可靠,适用于砷含量在0.005 0%~0.50%之间的粗锌中砷的测定。     

Determination of arsenic and arsenic compounds in natural gas samples

Organic arsenic compounds (trialkylarsines) present in natural gas were extracted by 10 cm³ of concentrated nitric acid from 1 dm³ of gas kept at ambient pressure and temperature. The flask containing the gas and the acid was shaken for 1 h on a platform shaker set at the highest speed. The resulting solution was mixed with concentrated sulfuric acid and heated to convert all arsenic compounds to arsenate. Total arsenic was determined in the mineralized solutions by hydride generation. The arsenic concentrations in natural gas samples from a number of wells in several gas fields were in the range 0.01–63 μ As dm^?3. Replicate determinations of arsenic in a gas sample with an arsenic concentration of 5.9 μ dm^?3 had a relative standard deviation of 1.7%. Because of the high blank values, the lowest arsenic concentration that could be reliably determined was 5 ng As dm^?3 gas. Analysis of nonmineralized extracts by hydride generation identified trimethylarsine as the major arsenic compound in natural gas. Low-temperature gas chromatography-mass spectrometry showed more directly than the hydride generation technique, that trimethylarsine accounts for 55–80% of the total arsenic in several gas samples. Dimethylethylarsine, methyldiethylarsine, and triethylarsine were also identified, in concentrations decreasing with increasing molecular mass of the arsines.     

氢化物发生-分光光度法连续测定砷和铅

本文提出了以氢化物与硝酸银反应为基础的在一份试样溶液中连续测定微量砷和铅的分光光度法。利用硝酸银-聚乙烯醇-乙醇溶液吸收砷化氢显色测定砷,硝酸银-明胶-乙醇溶液吸收铅化氢显色测定铅。方法灵敏快速,通过稀释有色吸收液可测定砷与铅含量相差较大的样品。应用于沉积物和土壤中砷和铅的分析,获得满意的结果。     

Determination of arsenic by hydride generation coupled to time-of-flight mass spectrometry with a gas sampling glow discharge

Hydride generation has been used with a gas-sampling glow discharge (GSGD) and time-of-flight mass spectrometry (TOFMS) for the determination of arsenic in solution. Helium, neon, hydrogen, and argon glow discharges have been successfully generated and characterized. Current–pressure–voltage curves were generated for each discharge in the presence and absence of hydride generation. The arsenic detection limit for each of the discharges was found to be 0.60 (HeGSGD), 3.8 (NeGSGD) and 6.4 ppb (H₂GSGD). The HeGSGD was found to be the most attractive source for arsenic determination due to the lower detection limit, higher sensitivity and greater stability. The figures of merit for these discharges were also compared to those obtained with hydride generation-inductively coupled plasma TOFMS. Noise power spectra obtained for the neon GSGD indicated that no discernible discrete-frequency (whistle-noise) components were present in the analyte signal.     

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).     

顺序注射氢化物发生-原子荧光光谱法同时测定中草药中As和Bi

建立了一种顺序注射氢化物发生-原子荧光光谱法同时测定中草药中的As和Bi含量的方法,考察了光电倍增管负高压、As和Bi灯电流、原子化器高度、载气流量、屏蔽气流量等因素对测定结果的影响。结果表明,载流HCl的浓度为0.3 mol/L,KBH4质量浓度为10 g/L时,同时测定As和Bi的效果最佳;在最佳实验条件下,As和Bi的检出限分别为0.058μg/L和0.006μg/L,加标回收率为94.6%~103.2%,相对标准偏差小于3.0%,中草药试样中共存的离子对As和Bi的测定没有干扰。该法操作方便、快速,用于中草药中As和Bi的同时测定,具有很好的可行性和实用性。     

Effect of cathodic electrolyte on the performance of electrochemical hydride generation from graphite cathode

The classic silver diethyldithiocarbamate (SDDC) spectrophotometric procedure for arsenic determination has been used for investigation of the effect of cathodic electrolyte on the performance of electrochemical hydride generation (HG) from graphite cathode. The results of this study show that the presence of a soft metal ion such as Cd(II), Sn(II) and/or Zn(II) in the acidic cathodic electrolyte can increase effectively the efficiency of electrochemical hydride generation and decrease the effect of interferences. The possible mechanisms of these effects have been discussed in detail. The parameters related to the electrochemical hydride generation were investigated. Also the characteristic data of the electrochemical hydride generation and common hydride generation by NaBH₄ were compared. Under optimised conditions, the system is selective to As(III) and total inorganic analyses can be performed after a pre-reduction stage prior to electrochemical hydride generation. This will allow the differential determination of inorganic arsenic species. The method is appropriate to the determination of 4-40 μg of each arsenic species.