脉冲放电氦光离子化检测器分析有机化合物的性能研究

研究本实验室组装的脉冲放电氦光离子化检测系统上PDPID的性能、各种操作参数对信号的影响、操作最佳化及信号线性。用该系统分析了汽油、酮醇混合物和痕量挥发性有机化合物等样品,它们的色谱图可以同FID相比。     

气相色谱-脉冲放电氦离子化检测器法同时测定乙烯或丙烯中5种无机气体

用带脉冲放电氦离子化检测器的气相色谱法同时测定乙烯或丙烯中氢气、氧气、二氧化碳、一氧化碳和氮气等5种无机气体的含量。充分气化的样品注入色谱仪,借助仪器的高度集约化操作程序及阀系统切换功能,样品流经2根微填充色谱柱,先后使氢气、氧气、二氧化碳、一氧化碳和氮气等5种气体得到分离和测定。这5种气体的体积分数均在0.50～10.0mL·m~(-3)内与其对应的峰面积呈线性关系,上述5种气体的检出限(3S/N)依次为0.02,0.01,0.02,0.03,0.01mL·m~(-3)。对一组5种气体的混合标准气体进行8次重复测定,其保留时间的相对标准偏差在0.040%～0.15%之间,其峰面积的相对标准偏差在0.98%～2.3%之间,证明此方法同时测定5种气体的重复性良好。对另一组5种气体的混合标准气体进行6次平行测定,测定值与已知值相符,测定值的相对标准偏差(n=6)均小于1.0%。     

高灵敏度的脉冲氦离子化检测器分析混合气体中的Kr、Xe

使用高灵敏度的脉冲氦离子化检测器(PDHID)气相色谱法对Kr、Xe浓度进行定量分析,并通过采用反应床除去杂质气体或与Kr、Xe难以分离的干扰组分N2、CH4和CO等,可使最低检测限达到Kr为7.931×10-8、Xe为7.186×10-8对Kr的测量相对偏差在2%以内,对Xe的测量相对偏差在6%以内.     

应用交流脉冲氦离子化检测器于气相色谱法测定变压器油中溶解气及水分

用自制的交流脉冲氦离子化检测器于气相色谱法测定变压器油中溶解气及水分.该检测器采用双向交流脉冲高压电源放电,避免了阳极溅射消耗和阴极污染问题.在未加任何净化、氦气纯度99.999%情况下,用气相色谱法测定了变压器油中7种溶解气体(H2,CO,CH4,CO2,C2H4,C2H6及C2H2),其检出限(3S/N)在0.1×10-6uL·L-1以下.检测器与程序升温、双柱切换等操作过程配合良好,而且可同时检测油中微水.     

Ar放电型检测器

随着高纯Ar在国防、科技、工业各领域的广泛应用,高纯Ar纯度的分析,对提高气体质量,保证用户合理使用,开发新材料和净化工艺有着积极的作用。为此要求发展一种新的、灵敏度更高、价格适宜的检测器,以解决目前普遍采用多台色谱仪和组合式分析仪在分析和定量上的困难。本文研制的检测器采用直流高压放电式园筒型结构,与国内、外研究及生产     

新型Ar放电型检测器的定量特性

Ar放电型检测器的工作电流主要是由Ar~+产生的。由于Ar的电离能很高(15.6eV),国外采用设备昂贵的高频电源,而国内多采用放射源。采用放射源虽然可以大大降低电离电压(500V左右),但放射源及载气渗入,不仅造反污染,而且仪器工作不稳。工作电流随仪器污染程度而异,以至最后必须定期清洗设备,以保证定量分析的正常进行。 本检测器采用直流高压源,整个GC系统无污染,工作电流稳定,可以长期运行,定量可靠,使用方便,操作无特殊要求,而且全部设备可以立足国内,便于普及,尤其适合于使用与生产单位对高纯氩的监     

氦离子化气相色谱仪的实验条件及其应用

论述了氦离子化气相色谱仪的原理、构造以及与该仪器用密切相关的多种影响因素。同时还介绍了该仪器的广泛应用以及在分析测试中的一些技巧,尤其是在气体工业和半导体制造工业所用化学品的分析。     

微波等离子体离子化检测器的应用研究—苯乙烯中乙苯的测定

微波等离子体是一种良好的激发光源和离子化源,可应用在气相色谱法中作通用或选择性检测器。其中表面波激发微波诱导等离子体离子化检测器(MIPID)对于挥发性有机物具有较好灵敏度,并且对某些永久性气体也有很好的响应。我们在完成MIPID检测器对有机和无机物响应特性研究的基础上,为了进一步考察这种MIPID检测器的可靠性和     

Relative Responses of Noble Gases Using a Pulsed Discharge Helium Photoionization Detector:Theoretical Calculation and Experimental Determination

The relative response factors（RRFs） for noble gas（Ng） were determined on a pulsed discharge helium photoionization detector. Using ab initio method, the atomic orbitals of noble gas were calculated and used to determine the number of ionizable electrons on the basis of the continuous emission of He2. The molar responses of noble gases is well correlated with the number of ionizable electrons.     

Pulsed discharge helium ionization detector

Summary A pulsed discharge helium ionization detector (PDHID) (patent pending) for gas chromatography has been developed. This detector uses a non-radioactive pulsed high voltage discharge source for generation of electrons and pulsed collection of these electrons. We have evaluated this detector for the analysis of a wide range of chemical compounds. In this paper the analytes are passed through the discharge since the permanent gases are difficult to ionize. The initial results for the permanent gases indicate that the PDHID can be used as a universal detector of contaminant traces at detection levels on the order of 1–20 pg. The response in this mode of operation is linear over four orders of magnitude.Dedicated to Professor Leslie S. Ettre on the occasion of his 70th birthday.     

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     

Pulsed discharge detector: theory and applications

The pulsed discharge detector (PDD) is a significant advancement in gas chromatography (GC) detector design which can be operated in three different modes: pulsed discharge helium ionization (He-PDPID), pulsed discharge electron capture (PDECD) and helium ionization emission (PDED). The He-PDPID can detect permanent gases, volatile inorganics and other compounds which give little or no response with the flame ionization detector (FID) and has significantly better limits of detection (minimum detectable quantities (MDQs) in low picogram range) than can be achieved with a thermal conductivity detector (typically not lower than 1 ng). The PDECD has similar or better sensitivity (MDQs of 10(-15) to 10(-12) g) than radioactive source ECD but does not require licensing, wipe tests and other administrative or safety requirements which have increased over security concerns. The PDED shows promise as an extremely selective and sensitive elemental detector but a commercial unit is not presently available. In this report, the theory of operation, applications of the PDD and the practical aspects of using this novel detector are presented.     

Effects of the Liquid Conductivity on Pulsed High-voltage Discharge Modes in Water

Spark, stream and corona pulsed high-voltage discharges in water induced by the various initial conductivities have been examined in this paper. The discharge modes changed from spark to corona discharge with the liquid conductivity increasing. The apparent production of OH radical and quantum yield generated by spark discharge in distilled water were 11.57 gmol/L and 0.0978 photon/s, respectively. A preliminary study on acid fuchsine (AF) treatment indicated that higher AF removal efficiency has been achieved by spark discharge. The process of degradation showed that the oxidative effects through OH radical oxidation did not play an important role and did increase with the discharge mode changing to spark discharge.     

可用于光催化研究的脉冲放电流光光源

利用针板形式的电极系统、正极性纳秒级脉冲电压供电、在空气和水混合条件下产生脉冲放电流光,研究了脉冲放电流光与电气参数、溶液电导率、鼓泡空气流量的变化关系,利用脉冲放电流光和纳米颗粒的半导体TiO2结合对酸性橙染料(AO7)溶液进行脱色效果的实验研究。结果表明,脉冲放电流光可以诱导TiO2发生光催化活性,在脉冲放电等离子体处理效果的基础上,提高AO7的脱色效果。     

Conversion of Methane to Hydrogen via Pulsed Corona Discharge

Experiments are performed to develop a pulsed corona discharge system for the conversion ofmethane to hydrogen at atmospheric pressure (≌760 Torr) without using a catalyst. The corona dischargewas energized by 10-12 μs wide voltage pulses (≤7 kV) at a repetition rate of about 1.0-1.5 kHz. Theresidual gases were characterized by mass spectrometry. The conversion of methane is as high as 50.8% producing the 70% yield of hydrogen. The influences of argon on the discharge of methane were studied.This result could be useful for the mass production of hydrogen in both academic and industrial point ofview.     

等离子体发射检测器在检测高纯氦气中微量氖气的应用

采用等离子发射检测器(PED)和氦离子放电检测器(DID)对重量法制备的氦气中微量氖气进行了检测,对比了微量氖气在两种检测器上的灵敏度和重复性。结果显示,PED对氖气的检测灵敏度较高,氖气含量在0.03~0.3μmol/mol范围与响应值呈良好的线性关系,r2=1.000,检测限小于1 nmol/mol,测定结果的相对偏差小于2%(n=6)。利用大气压离子质谱仪对检测限测试结果进行了验证。采用等离子发射检测器检测氦气中微量氖气的方法,可以降低微量氖气标准物质的定值不确定度,为研制高准确度微量氖气标准物质奠定基础。     

电化学-积分脉冲安培法的氨基葡萄糖盐酸盐检测

采用电化学-脉冲安培法分析氨基葡萄糖盐酸盐（GAH）检测的影响因素,包括积分电位、NaOH浓度和流速等．在实验范围内,积分电位增大,峰面积先增大后减小,背景信号大幅度提高,仪器噪音先升高再下降,积分电位以0.1 V为宜. 淋洗液浓度增大,保留时间不断缩短,峰面积先快速增大后趋于基本稳定,理论塔板数先增加后减小,淋洗液浓度以50 mmol·L^-1为宜. 流速增大,保留时间和峰面积均减小,淋洗液流速以0.6 mL·min^-1为宜. 文中比较了两种积分脉冲安培检测器（戴安ED3000 PAD和厦门纳精NJPAD）不同串联形式的氨基葡萄糖盐酸盐的转化量：ED3000前置串联,氨基葡萄糖盐酸盐的转化量约占其总含量的1.27%;NJPAD前置串联,氨基葡萄糖盐酸盐的转化量约占其总含量的2.79%.