An Automated Reagent-Addition System with an Infrared Drop Detector

The design and implementation of a computer-controlled automated reagent-addition system is presented. A special feature is the use of an infrared drop detector to sense that a drop of the titrant has indeed been added to the titrate. This system is particularly useful for the determination of stability constants of metal complexes. The operational procedure is briefly discussed and examples are given to show that reproducible results are obtained.     

流动体系高性能电流检测器的改进

采用在工作电极（ＷＥ）及辅助电极（ＣＥ）室衬垫尼龙网布的方法改进了本教研室提 出的 ＷＥ与ＣＥ正对面放置型的电流检测［１］。在进样 １００ μＬ样品（Ｂｒ－），流速２ ｍＬ／ｍｉｎ，检 测器电解效率达１８．９％，浓度电流线性范围为１０－２～１０－８ｍｏｌ／Ｌ，重复进样相对标准偏差小 于１％。     

气相色谱-微波等离子体炬双检测器及其气相色谱的响应特性

提出并建立了气相色谱-微波等离子体炬(MPT)原子发射光谱和离子化双检测器系统. 以Ar气作为等离子体工作气体, O2气作为等离子体屏蔽气体, 同时获得了被测组分的原子发射和离子化信息, 并对不同种类有机化合物的相对响应系数及检出限进行了测定.     

Calibration of a Multipoint Sampling System Connected with a Photoacoustic Detector

Abstract

Photoacoustic detection of gases in the air phase in combination with a multipoint sampling device transfers about 100 mL of air from each sample location to the next one, causing a considerable disturbance when small systems are sampled. In reactive systems, such as trace gas exchange in soil samples, a correction is required to determine the kinetic behavior of the systems. But this kinetic behavior is required in turn to calculate the correction in a repeated sampling sequence. A model was developed for reaction kinetics (zero-order or first-order) within closed systems and the sample transfer between these systems by a CBISS MK2 multipoint sampling system, connected with a Brüel & Kjær photoacoustic detector. By regression, the reaction kinetics is determined, and by simulation of the system in the absence of sample transfer, corrected data are generated. Comparison of experimental and modeled data revealed that part of the sample is transferred directly two systems further. In addition, a slight memory effect of the detector was revealed. These effects were accounted for in the model. If the correction is not made, biased results are obtained for the reaction kinetics.     

脉冲放电检测器

对不同模式脉冲放电检测器的结构、工作原理和应用进行了综述。并与性能的GC检测器相比较,讨论它们的优点、局限性和潜在的改进。     

Speciation of Arsenic Compounds in the Urine of Rats Orally Exposed to Dimethylarsinic Acid Ion Chromatography with ICP–MS as an Element-Selective Detector

A combined ion chromatography (IC) with inductively coupled plasma mass spectrometry (ICP—MS) system as an element-selective detector has been used for the determination of arsenic compounds. Seven arsenic compounds were separated by cation-exchange chromatography. Subsequently, the separated arsenic compounds were directly introduced into the ICP—MS and were detected at m/z =75. Detection limits for the seven arsenic compounds ranged from 0.8 to 3.8 μg As/l. The IC–ICP–MS system was applied to the determination of arsenic compounds in the urine of dimethylarsinic acid (DMAA)-exposed rats. DMAA was the most abundant arsenic compound detected. Arsenous acid, monomethylarsonic acid and trimethylarsine oxide were also detected.     

A New Conductivity Detector for Capillary Electrophoresis

IntroducnonHighperformancecapillaryelectrophoresis(HPCE)isanewanalyticaltechniqueandhasbeenappliedinvariousfields.InthedetectionmodesforHPCE,conductivitydetectionisaratheruniversalone,includingon-column',end-columnZandsuppressedconductivity'detection.Inthefirsttwo,thereisayieldedpotentialbetweentwoconductiveelectrodes,whichisinterferedbytheseparationvoltage.Theyieldedpotentialmayeasilydestroythegeneralconductivitymeter.ForthedetectorwithsuppressoF,itisdifficultinmanufactureanditsdeadvolum…     

溶液酸度在线检测装置的研制

研制了酸度在线检测装置，并应用于溶液酸度在线检测，溶液酸度在线检测装置，设有防污过滤器，自动采样器，蠕动泵，小型管道ｐＨ传感器和控制电路等，其特点为防污除油，随机自动采样，定时检测，全部管道化，可单独使用和计算机控制系统联网，适用于溶液酸在线分析，测定精度〈ｐＨ０．０５。     

毛细管区带电泳电化学检测器

本文阐述了毛细管区带电泳探针式安培检测器的构造、工作原理、理论及其与电泳系统的联结技术;介绍了该检测器的应用情况。     

Referenced Capacitively Coupled Conductivity Detector for Capillary Electrophoresis

A dual capacitively coupled contactless conductivity detector for capillary electrophoresis was developed. The two channels are arranged in a bridge configuration so that one of them acts as a reference whose signal is subtracted. This effectively compensates for the baseline conductivity of the separation buffer so that the electronic zero setting is not necessary. Changes in the buffer composition are automatically accounted for, as are temperature drifts. The system is demonstrated for the detection of inorganic model cations in capillary electrophoresis. Besides the use with two separate capillaries, one of which solely serves as reference, it was also found possible to use a single capillary which is looped back through the reference cell.     

微流控细胞芯片LED诱导荧光检测微系统

基于微流控细胞芯片分析技术和微机电系统(MEMS)加工技术, 设计制作了阵列式微流控细胞检测芯片, 采用自组装的顶窗型光电倍增管(PMT)和信号采集电路采集芯片微管道内流动细胞的荧光信号, 构建了一种针对低浓度细胞悬浮液的微流控细胞芯片发光二极管(LED)诱导荧光的快速检测微系统, 实现了对低浓度(≤40 Cell/mL)荧光标记的HepG2肝癌细胞悬浮液样本的定量计数和测试, 而且在血液细胞共存的条件下, 仍可以有效地对血液中少量HepG2肝癌细胞进行荧光计数和测试. 整个系统结构简单, 操作方便且检测灵敏度较高.     

氧-火焰离子化检测器的研制及应用

本文介绍选择测定复杂有机混合物中各含氧化合物的氧-火焰离子化(O-FID)检测器,该仪器是专门对氧响应的O-FID检测器,还报道了在O-FID检测器上对含氧化合物的定量校正工作。     

耦联式安培-电导检测器的研制及其在CE中的应用

毛细管电泳(CE)检测器的研究是一个具有挑战性的课题.目前已发展的一些检测方法有光学、电化学、质谱的和放射同位素等.     

聚二甲基硅氧烷封装石墨烯基柔性红外探测器的制备及其应用

采用热还原法在不同退火温度（从100到1200℃）下制备了一系列还原氧化石墨烯（rGO）薄膜，并通过X射线粉末衍射（XRD）、傅里叶变换红外光谱（FTIR）、拉曼光谱、四探针电阻仪和扫描电镜（SEM）对其进行了表征和分析.随后利用旋涂封装法制备了聚二甲基硅氧烷（PDMS）封装的石墨烯基柔性红外探测器（P-rGO-P），并成功用于红外激光、人体红外辐射、弯曲变化和压力探测.实验结果表明，采用不同温度还原的rGO薄膜封装得到的P-rGO-P柔性红外探测器在近红外（1064 nm）激光照射下均有响应，其中最高的光响应可达2.78 mA/W.此外，P-rGO-P柔性探测器对人体红外辐射和弯曲变化也具有快速、灵敏的响应，并且经过反复弯折仍能保持完整性与响应能力.     

Limit of Detection of 13 C Using an Atomic Emission Detector (MIP) Coupled to Gas Chromatography

Abstract

This paper presents the capability of using molecules labelled with ¹³ C and of measuring them by gas chromatography coupled to an MIP. The sensitivity of the detection of this stable carbon isotope has been optimised using non steroid anti inflammatory drugs such as Fenoprofen, Flurbiprofen, Ketoprofen and Diclofenac and applying a four factors experimental design. This work shows that the main factors acting on the sensitivity of the ¹³ C detection are the flow rates of hydrogen and helium (plasma gas). The linearity was demonstrated in the range from 50 to 300 pg of ¹³ C. The limit of detection calculated according to various methods (IUPAC, Oppenheimer and Quimby - Sullivan) gave the following results: 2 pg/μl, 12 pg/μl and 0.1 pg/s respectively. These results show that ¹³ C atomic emission is quite a specific and sensitive mode of detection of ¹³ C labelled molecules after gas chromatographic separation.     

Chlorine-Selective Detection in Supercritical Fluid Chromatography using a Coulson Electrolytic Conductivity Detector

Abstract

A Coulson electrolytic conductivity detector has been coupled successfully to a supercritical fluid chromatograph, providing chlorine-selective detection. This involves minimal modification of the detector and no modification of the SFC or its operation. The general operating parameters of the SFC/CECD system were established by direct injection of three probe compounds: chlordane, γ-lindane, and hexachlorobenzene. Next, the SFC separation of a test mixture containing phenol, γ-lindane, and several chlorinated phenols and related compounds was optimized using UV-Vis and FID detection. The mixture was then separated using the same chromatographic method but with the CECD in line with the UV-Vis detector. The response of the CECD was linear and selective for chlorinated compounds. Limits of detection for the test mixture by CECD ranged from 80 – 250 ng/μL, corresponding to approximately 14 – 44 ng of chlorine on column, and were dependent on chromatographic conditions, but independent of analyte structure.     

Development of an Atmospheric Pressure Glow Discharge Detector for Capillary Column Gas Chromatography

 The use of the change in the oscillation frequency of the current of a new atmospheric helium glow discharge for sensitive signal detection for gas chromatography is studied. The effluent of a capillary column is directed into the glow discharge cell perpendicular to the axis of the glow discharge that existed between a platinum anode and cathode. A stable discharge is obtained when several hundred volts are applied between the 0.2-mm gap between the anode and cathode. The effects of the electrode gap, discharge voltage and gas flow rate on the baseline frequency and discharge current were investigated. The chromatogram shows that the discharge current and discharge gap have a strong influence on the detector response. The discharge current shows positive peaks; however, frequency peaks are positive or negative depending on the discharge conditions. The response of the detector is in the femto-mole and pico-mole range for nonane and decane. Received August 5, 1997. Revision September 2, 1999     

毛细管电泳微机化扫描伏安检测器

描述了一种毛细管电泳微机化扫描伏安检测器,用微机通过D/A和A/D转换器控制扫描电压和采集电流信号,用12bit的D/A转换器和12bit的A/D转换器通过伏安仪分别与Ag/AgCl参比电极和工作电极相连,进行电位控制和数据采集.讨论了扫描电位的产生和数据采集的控制方法,并用本系统分离测定了对苯二酚和儿茶酚,结果令人满意.     

Computer Enhanced Spectroscopic Separation of Coeluted Components in Supercritical Fluid Chromatography Coupled with an Ultraviolet Multichannel Detector

Abstract

Computer enhanced spectroscopic separation technique has been applied to identification of coeluted components in supercritical fluid chromatography by using an ultraviolet photodiode array multichannel detector. The powerful function such as peak deconvolution procedure has successfully offered thespectroscopic complete separation for even partially or completely coeluted components in super critical fluid chromatography.