流动注射在线离子交换预富集—氢化物发生原子荧光光谱法测定痕量…

研究了流动注射液在线离子交换预富集及在线氢化物发生法与原子荧光光谱法的联用技术，设计了双柱交替正向富集和反向洗脱的在线离了交换流路系统。在采样频率为３０次／ｈ下，灵敏度较常流动注射氢化物发生原子荧光光谱法提高了１１倍，应用于环境水样痕量碲的分析，获得了满意的结果。     

流动注射在线共沉淀分离富集HG—AFS测定痕量锗

提出了一种流动注射在线共沉淀-氢化物发生-原子荧光光谱法测定痕量锗的分析方法。设计了在线共沉淀及氢化物发生流路和操作程序,选择了各项化学条件和流路参数。方法操作简便快速,分析速度为30/h,检出限为0.11ng,相对标准偏差（n=5)为5.6%,经国家一级地质标样分析验证,方法可靠实用。     

流动注射在线萃取非水介质氢化物发生原子荧光光谱法测定铜矿石中痕量锑

提出了一种流动注射在线萃取非水介质氢化物发生原子荧光光谱法测定铜矿石中痕量锑的新方法。在HCl介质中将Sb（Ⅲ）用流动注射在线萃取在磷酸三丁酯（TBP）中，与冰乙酸混合，再与溶解在N，N－二甲基甲酰胺（DMF）中的NaBH4混合、并反应，在有机相中产生SbH3，导入石英炉中进行原子荧光测定。方法检出限和精密度分别为0．54ng/mL和4．9％，分析结果与标准物质推荐值相吻合。     

流动注射氢化物发生原子荧光光谱法测定土壤中铅

土壤中铅的测定,以往多用石黑炉[1]或氢化物发生[2]原子吸收光谱法,本文通过试验表明,应用流动注射氢化物发生原子荧光光谱法测定,使方法更为简便、快速,结果准确可靠.     

碱性体系在线氢化物发生—原子荧光光谱法测定痕量铋

提出了一种碱性体系在线氢化物发生－原子荧光光谱法测定痕量铋的分析方法。设计了在线氢化物发生系统流路及操作程序，研究了碱性体系氢化物发生的各项最佳条件。方法操作简便快速，能有效地消除过渡元素的严重化学干扰。应用于黄铜标样中痕量铋的直接测定，获得满意结果。     

流动注射在线富集-FAAS测定合金钢中微量镍

提出了流动注射在线离子交换富集-火焰原子吸收光谱法测定合金钢中微量镍的分析方法.在线离子交换采用双柱正向富集和反向洗脱流路方式,使用80目732强酸型阳离子交换树脂在酸度为0.10mol/L HCl中富集样品中的Ni2+,并用2.0mol/L HCl洗脱.设计了流动注射在线离子交换富集双柱流路的操作程序,优化了各项仪器...     

流动注射-氢化物发生-原子荧光光谱法测定天然水中痕量镉

基于编结反应器,提出了流动注射-氢化物发生-原子荧光光谱法测定水中痕量镉含量的方法。样品与氨水-氯化铵缓冲溶液在线混合,产生的沉淀收集到编结反应器内壁,引入空气除去编结反应器内残留的溶液,泵入盐酸(3+97)溶液溶解沉淀,与硼氢化钾合并后用原子荧光光谱仪测定。在优化的试验条件下,当样品消耗15.6mL时,富集倍数为14倍,方法检出限(3S/N)为2.9ng.L-1,相对标准偏差(n=11)为3.4%。方法用于国家标准物质和天然水样中痕量镉的测定,测定值与标准值相符,天然水样的回收率在91.5%～107.5%之间。     

氢化物发生-原子荧光光谱法在金属材料痕量元素分析应用中的进展

对1992-2007年间氢化物发生-原子荧光光谱法在金属材料中痕量元素测定中的应用的新进展作了评述,对氢化物发生-原子荧光光谱法的发展前景作了展望.引述文献39篇.     

DMA 80直接测汞仪测定生活饮用水中汞

汞是生活饮用水的毒理学指标[1].汞被人体肠道吸收后,主要富集在肝、胃、脑组织等部位,可对神经系统造成危害[2].目前,测定水中汞的常用方法有氢化物发生原子荧光光谱法、冷原子吸收光谱法、双硫腙分光光度法、色谱法等[3-4].氢化物发生原子荧光光谱法是近年发展较快的一种分析技术,方法准确可靠、灵敏度高,但是该法存在样品处理耗时较长,需要消耗化学试剂等缺点.     

海水中痕量锌的流动注射在线预富集和电感耦合等离子体原子荧光检测

一种较新的螯合树脂CPPI,被用来从海水中富集痕量锌。在线预富集由流动注射分析仪控制,经富集浓缩后的锌试液亦由流动注射分析仪送往电感耦合等离子体原子荧光光谱仪检测。检出限在0.1μg/L以下。     

On-line preconcentration of phosphate onto molybdate form anion exchange column

In this paper, we describe an automated flow injection system for measuring the concentration of phosphate based on a fluorescence quenching reaction between Rhoadamine 6G and phosphomolybdate with a preconcentration column, which was packed with a molybdate-form ion exchange resin to collect and preconcentrate the phosphate in the sample solution. Rhodamine 6G was chosen because the reaction with phosphomolybdate was fast and did not require heat. For the construction of a stable flow injection system, an aqueous methanol solution was used as the cleaning reagent to overcome the precipitation of ion-associated complexes between Rhodamine 6G and phosphomolybdate or Rhodamine 6G and molybdate. For the preconcentration and collection of the phosphate ions in a water sample, a preconcentration column, which was packed with a molybdate-form ion exchange resin, was combined with the proposed flow injection system and applied to natural water samples containing low concentrations of phosphate.     

Continuous preconcentration system for nitrate ions using anionic reverse osmosis tubes coupled to an ion chromatograph

A continuous preconcentration system for nitrate ions was developed using cation exchange tubing made from Nafion perfluorosulfonic acid membrane. This method is based on ion exclusion effects and reverse osmosis phenomena. The system was evaluated by connecting it to an ion chromatograph. The concentration ratios could be increased by raising the pressures between the two sides of the cation exchange tubing. Twenty-fold concentration of nitrate ion was achieved when the pump pressure was 20 x 10(5) Pa. The relative standard deviations of the preconcentration ratio at four different pump pressures, 5, 10, 15 and 20 x 10(5) Pa were 1.2-2.8% (n = 5).     

Ion exchange-based preconcentration for the determination of anions by capillary electrophoresis

In the present paper a capillary zone electrophoresis (CZE)-compatible preconcentration technique for anions, based on ion exchange, is described. The described preconcentration approach has found limited use until recently because of the inherent elution step that leads to contamination of the sample with eluent components. In this paper, we describe an improved anion exchange-based preconcentration technique in which contamination of the sample with the eluent constituents, which occurs during anion elution from the preconcentration column, is eliminated by on-line chemical suppression on a packed-bed suppressor column. In the present communication, the basic principles of the proposed anion enrichment system are presented. The system was optimized, resulting in a minimal additional dilution of the eluted sample plug. This was achieved by the use of a computer-controlled, sensing/switching system. The effectiveness of the developed method was later tested on the determination of some anions in a synthetic sample using CE apparatus.     

Continuous preconcentration system for nitrate ions using anionic reverse osmosis tubes coupled to an ion chromatograph

A continuous preconcentration system for nitrate ions was developed using cation exchange tubing made from Nafion perfluorosulfonic acid membrane. This method is based on ion exclusion effects and reverse osmosis phenomena. The system was evaluated by connecting it to an ion chromatograph. The concentration ratios could be increased by raising the pressures between the two sides of the cation exchange tubing. Twenty-fold concentration of nitrate ion was achieved when the pump pressure was 20 × 10⁵ Pa. The relative standard deviations of the preconcentration ratio at four different pump pressures, 5, 10, 15 and 20 × 10⁵ Pa were 1.2 ～ 2.8% (n = 5).     

流动注射多功能溶液处理装置在原子吸收光谱分析中的应用

使用本实验室研制的流动注射多功能溶液处理装置，通过比较流动注射在线离子交换、在线液－液萃取火焰原子吸收光谱法测定铅和资金的效果，评价了该装置的性能。     

On-line cation-exchange preconcentration and capillary electrophoresis coupled by tee joint interface

An on-line preconcentration method based on ion exchange solid phase extraction was developed for the determination of cationic analytes in capillary electrophoresis (CE). The preconcentration-separation system consisted of a preconcentration capillary bonded with carboxyl cation-exchange stationary phase, a separation capillary for zone electrophoresis and a tee joint interface of the capillaries. Two capillaries were connected closely inside a 0.3 mm i.d. polytetrafluoroethylene tube with a side opening and fixed together by the interface. The preparations of the preconcentration capillaries and interface were described in detail in this paper. The on-line preconcentration and separation procedure of the analysis system included washing and conditioning the capillaries, loading analytes, filling with buffer solution, eluting analytes and separating by capillary zone electrophoresis (CZE). Several analysis parameters, including sample loading flow rate and time, eluting solution and volume, inner diameter and length of preconcentration capillary etc., were investigated. The proposed method enhanced the detection sensitivity of CE-UV about 5000 times for propranolol and metoprolol compared with normally electrokinetic injection. The detection limits of propranolol and metoprolol were 0.02 and 0.1 microg/L with the proposed method respectively, whereas those were 0.1 and 0.5 mg/L with conventional electrokinetic injection. The experiment results demonstrate that the proposed technique can increase the preconcentration factor evidently.     

流动注射在线吸着分离预浓集冷蒸气原子吸收法测定痕量镉

研究了IRC-718离子交换树脂、122螯合树脂和MuromacA-1树脂对镉的预浓集条件,建立了超痕量镉的流动注射在线吸着分离预浓集冷蒸气发生原子吸收光谱测定方法.在每小时进样60,60和45次速度下检出限(3σ)分别为3.0,3.0和2.4ng/L.线性范围0～0.3μg/L,对0.2μg/L镉测定的相对标准偏差为2.0%～2.6%(n=11).讨论了用这3种离子交换树脂微柱进行分离预浓集时条件参数的优化、抗干扰能力以及对天然水样的回收率,并分别进行了水样的测定.     

Determination of metal ions by ion chromatography with precolumn electrochemical preconcentration

The determination of heavy metals in concentrations less than 10(-6) mol/L by ion chromatography with conductivity detection requires a preconcentration step. Therefore, a special electrochemical equipment and method was developed for the on-line preconcentration of the divalent metals Ni, Co, Zn and Cd and their subsequent ion chromatographic determination. The loop of the injection valve of an ion chromatograph was replaced by an electrochemical flow-through-cell with a gold working electrode, a platinum auxiliary electrode and a silver/silver sulphate reference electrode. The preconcentration step consists of the deposition of the reduced metals on the electrode surface during a continuous pumping of the sample solution through the cell. After switching of the mobile phase through the cell, the analytes are injected after their reoxidation directly into the mobile phase. A new preconcentration step is simultaneously possible during the actual chromatographic run. An effective separation of the analytes from the matrix is also possible with the proposed system. A maximum of metal ion accumulation was obtained after 120 min in the galvanostatic mode on a gold tube electrode. The detection limits for Co(II), Ni(II), Zn(II) and Cd(II) were improved by a factor of 7.7, 10.4, 11.2, 14.0, respectively, and were in the 0.1 micromol/L concentration range with a RSD of 2-6%. The accumulation of metal ions was disturbed in the presence of Cr(III).     

Ionic liquids in enhancing the sensitivity of capillary electrophoresis: Off‐line and on‐line sample preconcentration techniques

The popularity of ionic liquids (ILs) has grown during the last decade in enhancing the sensitivity of CE through different off‐line or on‐line sample preconcentration techniques. Water‐insoluble ILs were commonly used in IL‐based liquid phase microextraction, in all its variants, as off‐line sample preconcentration techniques combined with CE. Water‐soluble ILs were rarely used in IL‐based aqueous two phase system (IL‐ATPS) as an off‐line sample preconcentration approach combined with CE in spite of IL‐ATPS predicted features such as more compatibility with CE sample injection due to its relatively low viscosity and more compatibility with CE running buffers avoid, in some cases, anion exchange precipitation. Therefore, the attentions for the key parameters affecting the performance of IL‐ATPSs were generally presented and discussed. On‐line CE preconcentration techniques containing IL‐based surfactants at nonmicellar or micellar concentrations have become another interesting area to improve CE sensitivity and it is likely to remain a focus of the field in the endeavor because of their numerous to create rapid, simple and sensitive systems. In this article, significant contributions of ILs in enhancing the sensitivity of CE are described, and a specific overview of the relevant examples of their applications is also given.     

Determination of thallium in natural waters by electrothermal atomic absorption spectrometry

Thallium is determined in natural waters by electrothermal atomic absorption Spectrometry after preconcentration. Thallium is oxidized and retained as the tetrachlorothallate (III) ion on an anion exchange column, followed by elution with ammonium sulfite solution. A concentration factor of 400 is achieved. The detection limit of the method is 3.3 ng/1.