甲醛被动式检气管的研制

在气体分子扩散和化学吸收的原理基础上，研制了一种测量甲醛气体含量的被动式检气管。检气管内的惰性担体上浸渍了酚酞亚硫酸钠溶液，遇甲醛后显色。显色长度的平方与甲醛浓度及采样时间的乘积成线性关系。检出下限为０．１７μｇ／ｍｌ（采样１．５ｈ）。它集采样与分析为一体，可以快速测定木材厂的甲醛储运房内气体中甲醛气体浓度。检气管结构简单，携带和操作方便。与传统的注射器采样比色分析法对比，相对偏差在±１４％内。检气管在避光条件下保存，保存期为三个月。     

一种便携式有毒气体被动采样检测装置的研制

以甲醛作为目标物,提出了一种基于扩散原理的具有大面积表面暴露的快速被动采样器及快速测定装置。该采样器不要求任何辅助采样泵使用该采样器研发的快速测定装置适用于现场气体样品的采集与测定。     

原位被动采样技术*

本文介绍了近些年来环境监测中三种新的原位被动采样技术-透析装置（Dialysis peepers）法、薄膜扩散平衡 (DET) 技术和薄膜扩散梯度 (DGT) 技术。综述了三种技术的原理、装置和特点。着重论述了三种技术在环境中的应用研究,包括透析装置以及DET 技术和DGT联用技术测量水体和沉积物孔隙水中可溶性金属的浓度;DGT技术可以作为一种预测重金属生物可利用性的新方法。DGT技术与其他技术（如DET、高离子选择电极、配体交换法、HPLC-ICP-MS等）联用可以更好地测量环境中重金属的形态。最后展望了原位被动采样技术未来的发展。     

大气持久性有机污染物(POPs)被动采样

大气是进行全球和区域持久性有机污染物(persistent organic pollutants,POPs)观测的良好介质.对<斯德哥尔摩公约>履约效力评估的需求,加速了大气POPs采样技术的研发与应用.大气POPs被动采样技术(passive atmospheric sampling,PAS)在近年来得到了飞速发展,日益成为大流量大气采样的重要补充手段,并显示出其在广大区域范围内实现大气POPs同步观测的优势.本文综述了大气PAS技术的基本原理,介绍、评价了几种主要大气PAS装置,重点分析了PUF-PAS的应用技术原理,介绍了大气PAS在全球各区域和不同研究领域的应用研究进展,分析了大气PAS研究领域的动态,提出了今后大气PAS研究中值得关注的研究内容和趋向.     

一种新型动力学被动采样技术—化学捕收器

化学捕收器（Chemcatcher）是一种新型可原位、连续、动态监测水环境污染物的被动采样技术。它以Fick扩散定律为定量基础,测定对象分为极性有机物、非极性有机物和无机物。本文介绍了该技术的装置组成、定量原理及其在水环境研究中的应用,并对此被动采样技术进行了评价与展望。     

被动采样技术在测定沉积物中有机污染物的生物可利用性和毒性中的研究进展

综述了被动采样技术作为仿生萃取方法在测定沉积物中有机污染物的生物可利用性和毒性中的应用。对比了半渗透膜装置、聚乙烯膜装置、聚甲醛树脂萃取和固相微萃取这些常见被动采样技术在使用过程中的优缺点,并针对被动采样技术应用中的问题,提出可能的解决手段和研究需求。     

环境监测中两种原位被动采样技术——薄膜扩散平衡技术和薄膜扩散梯度技术

介绍了近年来环境监测中两种新的原位被动采样技术.薄膜扩散平衡(DET)技术和薄膜扩散梯度(DGT)技术.综述了DET技术的原理、装置的组成和构造、特点及在环境监测中的应用.关于DGT技术着重论述了对被监测物质有效态的累积原理,总结了扩散相和结合相的发展,并展望了未来的发展方向.     

便携式温度计校验仪的研制

介绍便携式温度计校验仪的工作原理及研制过程。对该仪器的恒温槽体机械结构、制冷器和散热器的设计、恒温槽体温度测量及控制等进行了详细叙述。该仪器提供的温度场稳定、均匀，在-20～100℃范围内可任意设定温度。解决了温度计现场快速校准的问题。     

Catalytic systems based on carbon supports for the low-temperature oxidation of carbon monoxide

Catalytic systems containing palladium, copper, and iron compounds on carbon supports—kernel activated carbon and fibrous carbon materials (Karbopon and Busofit)—for the low-temperature oxidation of CO were synthesized. The effects of the nature of the support, the concentration and composition of the active component, and the conditions of preparation on the efficiency of the catalytic system were studied. The catalytic system based on Karbopon exhibited the highest activity: the conversion of carbon monoxide was 90% at room temperature and a reaction mixture (0.03% CO in air) space velocity of 10 000 h^?1. It was found that the metals occurred in oxidized states in the course of operation: palladium mainly occurred as Pd⁺, whereas copper and iron occurred as Cu²⁺ and Fe³⁺, respectively.     

Polyoximes based on the alternating carbon monoxide copolymers

A new efficient method for the synthesis of polyoximes was developed based on the oximation of the alternating carbon monoxide copolymer with ethylene or styrene in the polar aprotic solvent.     

On-line analysis of products from hydrogenation of carbon monoxide by capillary gas chromatography with thermal conductivity detection

A combination of thermal conductivity detectors with capillary columns is used for on-line analysis of the products from a micropolit plant for the study of carbon monoxide hydrogenation. The system includes an automatically operated heated tenport sampling valve, a HP-5890-A gas chromatograph fitted with two capillary columns and thermal conductivity detectors, and a logging/controlling system. The single column design means that two analyses can be done simultaneously in one chromatograph and offers high versatility with the possibility of combining different capillary columns to cope with the needs of variable process conditions and catalyst selectivities.     

Ambient temperature gas purifier suitable for the trace analysis of carbon monoxide and hydrogen and the preparation of low-level carbon monoxide calibration standards in the field

A novel gas purifier based upon Sofnocat 682, a catalyst containing platinum and palladium on a hydrophobic tin oxide support, is described for the quantitative removal at ambient temperatures of ppm (v/v) and sub-ppm (v/v) levels of carbon monoxide and hydrogen from air and nitrogen gas cylinders. This method provides a simple means of generating either a laboratory or field source of “zero grade” gas for both the trace analysis of carbon monoxide and hydrogen and the preparation of working calibration gas standards of carbon monoxide by using a simple one-step dilution of a higher concentration certified gas standard.     

Reaction of carbon monoxide and hydrogen on neutral Nb8 clusters in the gas phase

Reactions of neutral V(n), Nb(n), and Ta(n) metal clusters (n< or =11) with CO+H(2) mixed gases and CH(3)OH in a flow tube reactor (1-50 Torr) are studied by time of flight mass spectroscopy and density functional theory calculations. Metal clusters are generated by laser ablation, and reactants and products are ionized by low fluence (approximately 200 microJ/cm(2)) 193 nm excimer laser light. Nb(n) clusters exhibit strong size dependent reactivity in reactions both with CO+H(2) and CH(3)OH compared with V(n) and Ta(n) clusters. A "magic number" (relatively intense) mass peak at Nb(8)COH(4) is observed in the reaction of Nb(n) clusters with CO+H(2), and CH(3)OH is suggested to be formed. This feature at Nb(8)COH(4) remains the most intense peak independent of the relative concentrations of CO and H(2) in the flow tube reactor. No other Nb(n), Ta(n), or V(n) feature behaves in this manner. In reactions of CH(3)OH with metal clusters M(n) (M=V, Nb, and Ta, n=3-11), nondehydrogenated products M(n)COH(4)/M(n)CH(3)OH are only observed on Nb(8) and Nb(10), whereas dehydrogenated products M(n)CO/CM(n)O are observed for all other clusters. These observations support the suggestion that CH(3)OH can be formed on Nb(8) in the reaction of Nb(n) with CO+H(2). A reaction mechanism is suggested based on the experimental results and theoretical calculations of this work and of those in the literature. Methanol formation from CO+H(2) on Nb(8) is overall barrierless and thermodynamically and kinetically favorable.     

State of the copper ions in the catalysts for oxidation of carbon monoxide to carbon dioxide

The state of the copper ions in the catalysts for the oxidation of carbon monoxide to carbon dioxide, prepared by dissolving an activated copper-containing aluminum alloy in water followed by calcination (method A) and by impregnation of the support produced by dissolving activated aluminum in water with copper nitrate solution (method B), was investigated by diffuse reflection electronic spectroscopy. It was established that the catalysts contain Cu ²⁺ ions stabilized in fields of octahedral symmetry. The concentration of these ions depends on the method of synthesis of the catalyst, its copper content, and the pretreatment temperature. It is higher in the samples produced by impregnation than in the samples produced by fusion; increase in the amount of copper leads to a decrease while increase in the calcination temperature leads to an increase in the concentration of the above-mentioned ions. Treatment of the oxide systems with the reaction mixture does not affect the state and concentration of Cu ²⁺. The catalytic activity of the samples depends on the method of preparation and increases with decrease in the amount of Cu ²⁺ (O_h) and with increase in the content of the CuO phase in the system.N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, Moscow 117913. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 4, pp. 786–790, April, 1992.     

Enzyme-linked immunosensor based on super paramagnetic nanobeads for easy and rapid detection of okadaic acid

Okadaic acid (OA), a lipophilic phycotoxin highly toxic to humans is produced by toxigenic dinoflagellates. The need to develop high performing methods for OA analysis able to improve the traditional ones is evident. In this work, competitive indirect enzyme-linked electrochemical immunosensor based on super paramagnetic nanobeads has been developed for the detection of OA. Streptavidin-coated magnetic beads were used as support to immobilize the biotinylated OA. Preliminary, colorimetric tests were performed in order to optimize different experimental parameters. Electrochemical detection was carried out by differential pulse voltammetry (DPV). The limit of detection (LOD) (0.38 μg L⁻¹), the mid point value (IC₅₀) (3.15 μg L⁻¹) and the time needed (60 min) for analysis of a real sample validated the developed electrochemical immunosensor as a promising tool for routine use. The matrix effect and the recovery rate were also assessed, showing an excellent percentage of recovery.     

New catalysts for the oxidation of carbon monoxide

Catalytic activity of binary and multicomponent semiconductors of the ZnSe-CdTe system prepared in a form of powders and nanofilms in CO oxidation was studied by pulsed flow and circulation flow methods. The conditions of maximal CO conversion were determined from the results of investigation of individual and joint adsorption of the reactants in a broad temperature range, and the specific activity of the catalysts was determined by the specific reaction rate at the specified temperature and composition of the reaction mixture. A noticeable catalytic transformation of CO on the semiconductors under study (up to 78.5%) was noted as low as room temperature. It was concluded that the oxidation of CO and adsorption of the CO + O₂ mixture proceeds mainly by the collisional mechanism. It was noted that the high activity of studied catalysts already at room temperature (the (ZnSe)_0.05(CdTe)_0.95 solid solution possessed the highest activity) and the absence of high-cost metals in their composition allow us to recommend them as low-temperature, relatively low-cost catalysts for the neutralization of CO (carbon monoxide).     

Study of enzyme biosensor based on carbon nanotubes modified electrode for detection of pesticides residue

The paper describes a controllable layer-by-layer （LBL） self-assembly modification technique of multi-walled carbon nanotubes （MWNTs） and poly（diallyldimethylammonium chloride） （PDDA） towards glassy carbon electrode （GCE）, Acetylcholinesterase （ACHE） was immobilized directly to the modified GCE by LBL self-assembly method, the activity value of AChE was detected by using i-t technique based on the modified Ellman method. Then the composition of carbaryl were detected by the enzyme electrode with 0.01U activity value and the detection limit of carbaryl is 10^- 12 g L ^-1 so the enzyme biosensor showed good properties for pesticides residue detection.