在线氧含量分析中的自动反吹

为解决在线氧含量分析测试仪表常被聚合物堵塞的问题，提出了自动反吹的时序分配和实施控制方案，从而为安全生产提供了保障。     

小型管道pH传感器的研制及其于自动化在线监测中的应用

研制了数种结构简单、实用的小型管道玻璃膜ｐＨ传感器和小型管道ＰＶＣ膜ｐＨ传感器，并将其与普通的酸度计和自动采样器（自制）等合理组合，构成了自动采样酸度在线监测装置，该装置与计算机自动化控制系统联网，已用于稀土萃取分离槽液的酸度自动化在线监测，结果满意。     

微型柱在线分离-ICP-MS法测定高纯氧化铕中的14个稀土杂质

研究了微型柱在线分离-电感耦合等离子质谱法（ICP-MS）测定高纯Eu2O3中痕量Tm的方法，研制了Cyanex272负载树脂微型分离柱，优化了分离Eu2O3基体的实验条件，在线分离测定时间为25min。建立了在线柱分离测定Tm，内标补偿法直接测定其余稀土杂质的高纯Eu2O3中14个稀土杂质的ICP-MS分析方法。方法检出限为0.01μg/g-0.15μg/g，加标回收率为91.5%-110%,相对标准偏差为1.7%-4.9%。可满足快速测定99.999%Eu2O3中14个稀土杂质的要求。     

On-column polymer-imbedded graphite inlet electrode for capillary electrophoresis coupled on-line with flow injection analysis in a poly(dimethylsiloxane) interface

A method for coupling an electrophoretic driven separation to a liquid flow, using conventional fused-silica capillaries and a soft polymeric interface is presented. A novel design of the electrode providing high voltage to the electrophoretic separation was also developed. The electrode consisted of a conductive polyimide/graphite imbedded coating immobilized onto the capillary electrophoresis (CE) column inlet. This integrated electrode gave the same separation performance as a commonly used platinum electrode. The on-column electrode also showed good electrochemical stability in chronoamperometric experiments. In addition, with this electrode design, the electrode position relative to the inlet end of the CE column will always be constant and well defined. The on-line flow injection analysis (FIA)-CE system was used with electrospray ionization (ESI)-time of flight (TOF)-mass spectrometry detection. The preparation of the PDMS (poly(dimethylsiloxane)) interface for FIA-CE is described in detail and used for initial tests of the on-column polymer-imbedded graphite inlet electrode. In this interface, a pressure-driven liquid flow, a make up CE electrolyte and a CE column inlet meet in a two-level cross (95 microm ID) in the PDMS structure, enabling independent flow characterization.     

Synthese de Nouveaux Derives Phosphones a Chaine Perfluoree et Leurs Proprietes Adhesives Sur Acier

Ce mémoire décrit la synthèse de phosphonates comportant une chaîne perfluorée. Ces composés sont obtenus par la télomérisation d'allylphosphonates de dialkyle en présence d'un agent de transfert fluoré de type mercaptan. Ensuite, nous employons deux méthodes de déalkylation menant sélectivement soit au monoacide soit au diacide phosphonique. Tous ces produits comprenant une extrémité de chaîne phosphonée, sous forme acide ou ester, ont été caractérisés et leur adhésion respective sur des plaques d'acier est étudiée. Ces tests montrent que le monoacide phosphonique est un excellent promoteur d'adhésion et qu'il est aussi efficace que le diacide. This article describes the synthesis of phosphonic derivatives bearing a perfluorinated chain. These compounds have been synthetized by telomerization of dialkyl allylphosphonate with a fluorinated transfer agent type mercaptan. Then two methods of dealkylation leading selectively were used to mono or to diacid phosphonic moieties. All the products bearing phosphonic end-groups, more or less acidic, have been characterized and their own adhesion on steel plates is studied. These tests show that phosphonic monoacid is an excellent adhesion promoter on steel, as efficient as the diacid compound.     

Electrochemical detection of nitrate,nitrite and ammonium for on-site water quality monitoring

This review examines the most recent electrochemical developments for nitrate, nitrite and ammonium detection for on-site water monitoring. There remains a high demand for effective field-based detection of the dissolved inorganic nitrogen (DIN) analytes to aid in mitigating nitrogen loading. Electrochemical approaches show increasing potential to fill this role as advancements in nanotechnology continually improve analytical performance and on-site applicability. However, translating these improvements into the field still faces the resonating challenges of reaching analytical proficiency (selectivity, sensitivity, robustness, stability), practical end-user functionality, minimal matrix interferences and cost effectiveness. Herein, we elaborate on these challenges via a critical evaluation of current studies and examine how realistic the prospects of on-site nitrate, nitrite and ammonium are. We also present recommendations in addressing these gaps to conclude the review.     

An on‐line sample pretreatment technique for the HPLC analysis of plant samples

A continuous‐flow, on‐line sample pretreatment technique using a silica gel microsyringe extractor has been developed. All steps including extraction, separation, clean‐up, and concentration occur in the microsyringe. The overall sample pretreatment process takes <10 min per sample. Different polarity chemicals in the plant sample are successively extracted and separated, and analyzed in parallel using HPLC–UV and HPLC–UV–MS/MS. Polycyclic aromatic hydrocarbons, alkylphenols, and plant hormones were determined as model compounds for nonpolar, intermediate polarity, and polar fractions, respectively. All the parameters that influence the extraction and separation efficiency of the microsyringe extractor have been optimized and evaluated. Under the optimized conditions, recoveries of target compounds ranged from 78.4 to 101.9%, the RSD was <12.8% and the square of the correlation coefficient was >0.99. Complex plant samples of Sambucus Mandshurica Kitag have been tested using this method. Fluorene, phenanthrene, pyrene, and plant hormones were detected in all the samples, and concentrations ranged from 24.2–34.9, 43.8–67.1, 25.9–29.2, and 14.5～110.8 ng/g, respectively.     

Continuous Spectroscopy Characterization of Emulsions

In emulsion polymerization, the formation of particles has an important effect on the rate of reaction and on the final properties of the latex. To investigate particle nucleation mechanisms in emulsion polymerization it is necessary to establish the initial conditions of the emulsified system before the reaction takes place. This research reports on a technique to continuously monitor the droplet size distribution of liquid-liquid emulsions using spectroscopy. The on-line particle characterization methodology is based on an integrated sampling and dilution strategy combined with spectroscopy methods. It is shown that the sampling system integrated with a multiwavelength turbidity detector provides reliable estimates of droplet populations as function of the dispersed phase concentration in emulsions of saturated hydrocarbons. The results provide not only the groundwork necessary for the elucidation of particle nucleation during emulsion polymerization process but also suggests the potential of this combined technology to further our understanding of liquid-liquid emulsions.     

Construction of a portable sample preparation device with a magnetic poly(methacrylic acid‐co‐ethylene dimethacrylate) monolith as the extraction medium and its application in the enrichment of UV filters in water samples

A portable sample preparation device with a magnetic polymer monolith as the extraction medium was constructed. The monolith was synthesized by polymerizing methacrylic acid and ethylene dimethacrylate around a cylindrical magnet. In this way, the monolith with a magnetic core could be readily attached to the extraction device by magnetism. The constructed device was evaluated for the enrichment of UV filters in water samples, followed by high‐performance liquid chromatographic analysis. The extraction efficiency for the targets was satisfactory with no matrix interference. Good linearities were obtained for the UV filters with the correlation coefficients >0.9986. The limits of detection and quantification for the UV filters were 0.3–0.8 and 1.0–2.4 ng/mL, respectively. The recoveries of the UV filters from the spiked water samples at the concentration of 100 ng/mL were 95.3–101.7%, with relative standard deviations <10%. Accordingly, the proposed portable device was demonstrated to be suitable for on‐site simultaneous sampling, purification, and preconcentration within a single step.