Determination of trivalent europium using flow injection chemiluminescence method

A simple flow injection chemiluminescence (CL) analysis method for the determination of europium in mineral samples is reported. It is based on luminescence produced by NaIO₄-H₂O₂ CL system sensitized by [Eu(EDTA)]⁻. The relative chemiluminescence intensity of the Eu³⁺-EDTA-NaIO₄-H₂O₂ system is proportional to the amount of Eu³⁺. The optimized experimental conditions were investigated. The linear range and detection limit for Eu³⁺ are 2.0×10⁻⁷ to 1.0×10⁻⁵ and 6.2×10⁻⁸ M, respectively. The sample throughput of the method is 80 samples/h. This method was successfully applied to the determination of europium in rare earth oxides. And the mechanism of chemiluminescence is proposed.     

手性联萘酚类配体修饰的氢化物还原剂的应用

综述了手性联酚化合物作了手性配体在一系列不对称选择性还原反应（包括对不饱和羰基化合物，酰基锡烷，亚胺，酸酐，内消旋环１，２－二羰基亚胺等的不对称还原反应）中的应用，参考文献２７篇。     

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碲的研究

研究了流动注射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子交换流路系统。在采样频率为３０次／ｈ下，灵敏度较常规流动注射氢化物发生原子荧光光谱法提高１１倍。应用于环境水样中痕量碲的分析，获得了满意的结果。     

Flow injection potentiometric detection of trimethylamine in seafood using tungsten oxide electrode

A simple flow injection gas/diffusion method for the determination of trimethylamine (TMA) in seafood with potentiometric detection using tungsten oxide electrode has been developed. The method is based on the diffusion of TMA through a PTFE membrane from a sodium hydroxide donor stream to a phosphate buffer acceptor stream. The TMA in the acceptor stream passes through an electrochemical flow cell containing a tungsten oxide wire and a silver/silver chloride electrode, where TMA was sensitively detected. The parameters affecting the sensitivity of the electrode such as sodium hydroxide concentration, buffer concentration, pH, flow rate and injected volume were studied in details. The electrode response was linear in the concentration range from 1 to 10 μg ml⁻¹ TMA with a correlation coefficient (R²) of 0.991 and a detection limit of 0.05 μg ml⁻¹ TMA. The intra- and inter-days precision (R.S.D.) was found to be, respectively, 1.20 and 1.6% (n=6). The method was applied to the determination of TMA in fish tissue and recoveries of 99-100% were obtained for fish extracts. Results were in close agreement with those obtained by the existing classical official method. Common interference from those species that can diffuse through the membrane were removed by the addition of formaldehyde to the seafood extract. The method is simple, feasible with satisfactory accuracy and precision and thus, could be used for monitoring seafood quality with a sampling rate of 20±2 sample h⁻¹.     

流动注射胶束增溶分光光度法同时测定镁砖中微量铁铝

本文研究了铁铝－ＣＡＳ－乳化剂ＯＰ胶束增溶体系的ＦＩＡ－光度法时测定镁砖中微量铁铝，该法操作简便，快速可靠，进样频率４５样次／ｈ，ＲＳＤ＜３．４％和５．８％。结果令人满意。     

流动注射分析中样品的分散与载流流速关系的研究

根据串联釜模型，流动注射分析响应曲线的峰高与峰面积、１／４峰高处的峰宽两个因素有关，这两个因素与载流流速的关系分别可以用不同的ｅｘｐ（－ｑ）多项式表示（ｑ是无量纲流速），由于分散度与峰高成反比，分散度随流速的变化关系由此能够很好地得到解释。     

过程监测与控制中的流动注射方法

本文综述了过程监测与控制中的流动注射方法,内容包括仪器装置、技术及其在工业生产、环境污染、药物溶出和生物过程分析中的应用。     

Comparison of metallic electrodes for constant-potential amperometric detection of carbohydrates,amino acids and related compounds in flow systems

Constant-potential amperometric detection of carbohydrates, amino acids, and other aliphatic organic compounds is possible by means of their oxidation in alkaline solution at a variety of metal/metal oxide electrodes including Pt, Au, Cu, Ni, Ag and Co. The experimental conditions required for optimum detection and the analytical performance obtainable vary widely for different electrode materials and analytes. In this work, the cyclic voltammetric behavior exhibited by selected analytes (glucose, glycine, lactic acid, ethylamine and ethanol) at each of these electrodes was used to determine the optimum potentials suitable for flow detection so that the capabilities of the different metal electrodes could be evaluated and systematically compared. In general, the Cu electrode was found to provide superior detection capabilities in terms of its range of response, detection limits and especially stability. Despite the fact that Pt and Au are typically used only with a pulsed applied potential, both can provide long-lived constant-potential detection of carbohydrates and other analytes at low concentrations if the potentials ere carefully chosen and the electrodes are allowed to undergo an initial stabilization period.     

Electrothermal atomic absorption spectrometric determination of lead in high-purity reagents with flow-injection on-line microcolumn preconcentration and separation using a macrocycle immobilized silica gel sorbent

A fully automated procedure for the determination of ng l⁻¹ amounts of lead has been developed using flow injection (FI) online column preconcentration coupled with electrothermal atomic absorption spectrometry (ETAAS). The proposed FI manifold and its operation make possible the introduction of the total eluate volume into the graphite atomizer, avoiding the necessity for optimization of subsampling the eluate. The interference of other heavy metal ions due to competition for active sites of the sorbent is overcome using a highly selective macrocycle immobilized on silica gel (Pb-02). Lead is adsorbed on a microcolumn (50 μl) packed with Pb-02, and after washing the column with dilute nitric acid, air is introduced to remove all solution from the column and connecting tubing. The sorbed analyte is then eluted quantitatively into the graphite tube atomizer, preheated to 100°C, with 36 μl of ETDA solution (0.035 mol l⁻¹, pH 10.5), propelled by air in order to minimize dispersion. The collection efficiency was 77% and with a sample loading flow rate of 3 ml min⁻¹ and a 60 s preconcentration time, the enhancement factor was 77 and the throughput was 17 samples per hour. The relative standard deviation (n = 10) at the 300 ng l⁻¹ level was 2.7%, and the detection limit (3σ) was 0.4 ng l⁻¹. No interference from heavy metals was observed, but ions of Ba²⁺, Sr²⁺ and K⁺ were found to interfere when the concentration ratios of interferent to lead exceeded values of 2000, 20 000 and 200 000, respectively. Quantitative recovery of lead was achieved from sodium, magnesium, aluminum, lanthanum and heavy metal salt solutions. The high selectivity and sensitivity, combined with extremely low blank values, make the proposed technique particularly attractive for the analysis of high-purity reagents, semiconductors and other high-purity materials. Results are presented for the determination of lead in some high-purity reagents.