CP3800型气相色谱仪特殊故障排除一例

介绍了CP 3800型气相色谱仪一例特殊故障产生的原因及排除方法,强调了色谱仪主机界面中色谱柱参数正确设置的重要性和注意事项。     

SP3420型气相色谱仪常见故障分析及处理

SP3420型气相色谱仪主要包括两个系统,即气路系统和电路系统。气路系统主要有进样器、载气过滤器、色谱柱、压力表、TCD检测器等;电路系统包括各部件的稳压电源、温控装置、外部事件控制继电器、BF9202数据处理工作站等。判断气相色谱仪的故障特征,就要熟悉色谱仪的工作原理,以及气路和电路这两大系统,特别是构成这两个系统部件的结构和功能,熟悉主机线路图和各系统的原理。搞清楚控制单元和被控对象之间的关系,各连接插接件引线的编号和去向,仔细检查电路板,寻找故障点。色谱故障的排除既要做到局部又要考虑到整体,逐步排除产生故障的原因,把故障范围缩小。一般采用排除法,可以缩小故障检修范围,达到事半功倍的效果。     

自制单片机提高Varian3700气相色谱仪的程控能力

由北京分析仪器厂引进的Varian 3700气相色谱仪是美国七十年代产品。与较新仪器比较,存在着自动程序控制能力较低的不足。如:主机与数据处理机等配套仪器不能联动,柱箱程序升温只能预设定一阶,毛细管柱进样分流阀必须手控等。这些不足,在采用毛细管色谱法和某些新的进样方式时尤为突出,而对选择最佳升温速率以提高分离度也是很不利的。我们通过自行设计和按装的一套单片微处理机及附属设备,初步实现了对原主机控制电路的改造。已完成的主要功能为:(1)主机程序升温和数据处理机的同步启动;(2)毛细管柱进样分流阀的程序开关;(3)柱箱温度可进行三阶线性程序升     

使用气相色谱仪和记录器的一些经验

介绍了使用各类型气相色谱仪和记录器的一些经验:(1)在色谱柱和检测器间连个三通管,用不锈钢管将分流的气体通至仪器的上方,可以确定嗅出的某些气味组份与色谱图上的某些峰的关系,便于检出有气味组份;(2)改进102G型或Pye105型气相色谱仪的进样器;(3)在缺乏备用集成电路和小型热电偶的情况下,简化Pye105型气相色谱仪的电路,使其组份出口加热器的温度控制器正常工作;(4)将Pye105型气相色谱仪的控制电磁阀的交流电源改为直流电源,使因锈蚀增大了磁阻的电磁阀正常工作;(5)Pye105型微电流放大器的防潮;(6)PHILIPS PM8000型平台式记录器的记录纸的防潮;(7)防止记录笔尖的堵塞。     

GC-14A气相色谱仪分流装置的故障排除

 介绍了日本岛津公司产GC-14A气相色谱仪中SPL- 14分流/不分流进样器的连接管引起的故障现象及排除方法。指出该公司产同类型带有分流/ 不分流装置的气相色谱仪,若长期分析高沸点油状化合物,则应定期清洗连接管,及时清除 堵塞物,以保证测试数据有较好的重现性。     

便携式低压钠灯电子镇流器设计

针对现有低压钠灯光源功耗高、输出稳定性差的问题，提出一种便携式低压钠灯电子镇流器设计方法。通过分析低压钠灯伏安特性曲线，对比现有典型低压钠灯镇流器的特点，根据低压钠灯工作原理设计相应的镇流电路。在电磁滤波的基础上，加入功率因数校正及恒功率控制电路以保证电路输出功率的稳定，加入LC谐振电路以保证电路输出频率的稳定，通过反馈控制实现电路的可靠工作。采用GP20NA-1型低压钠灯作为输出对象对低压钠灯电子镇流器输出电压、电流及低压钠灯辐射光谱进行验证，结果表明，低压钠灯电子镇流器输出功率稳定，常态下输出功率不大于20 W，钠灯辐射光谱稳定于589.3 nm，在光学计量、实验室照明等方面具有较高的应用价值。     

BAIRD Ps-6真空型电感耦合等离子发射光谱仪的故障分析与对策

对Ｐｓ－６型光谱仪作了简介的基础上，从联锁保护电路入手，选择了射频发生器。相检测电路，气路，真空系统，光路准直监视系统，光电倍增管和高压电路等八例有代表性，。已排除的故障实例深入进行了研究，提出了排除故障的思路与办法。     

静态箱法气相色谱法自动检测农田N2O排放

Ｎ２Ｏ自动观测系统由微机控制电路和气路，使采样箱、气相色谱仪（ＧＣ）和积分仪自动工作，系统可连续采样分析，自动存储色谱数据，并可同时测定存储温度和辐射等气象数据，系统从放置于田间可自动开关箱盖的采样箱中，依次抽取空气样品，经除水、ＣＯ２处理后送入气相色谱仪分析Ｎ２Ｏ浓度，箱中浓度随时间的变化计算Ｎ２Ｏ的排放通量。     

烷基苯类化合物Kovats指数的高再现性测定方法研究

1引言烷基本类化合物在OV－101柱上的Kovats保留指数（简称Kovats指数）再现性较差，以至不能直接用文献保留数据定性。本文提出了一种新的Kovats指数的测定、计算方法，较好地解决了这一问题。2实验部分2．1仪器与试剂GC－9A气相色谱仪，配CR－ZA（X）色谱数据处理机。C5～C10烷基本类化合物（Fluca试剂），C6～C11正构烷烃（上海分析试剂厂色谱纯试剂），各组份按相近量配成混合标作。2，2色谱杂件色谱柱：50mXO．2mm（i．d）OV－101格融石英毛细管柱（日本岛津公司），理论塔板数174，000；载气：N；，流速50mL／min（表观值）…     

WFX—IE型原子吸收分光光度计的故障与修理

介绍了WFX—1E型原子吸收分光光度计的几例典型故障现象与故障排除。修理方法简捷奏效,目的是为此类大型分析仪器的电路修理提供和积累一点经验。     

ZnO纳米粒子多相催化n-C7H16-SO2气相光化学反应的研究

利用自制的ZnO纳米粒子和商品的ZnO粒子，研究了ZnO粒子多相催化n-C6H16- SO2的气相光化学反应。利用气相色谱－质谱联用仪（GC／MS）和气相色谱仪（GC ）对反应物n-C6H16和SO2以及主要气相产物3－庚酮进行了定量分析，考察了不同 条件下它们的降解和产生趋势，初步探讨了氧气和水蒸气对ZnO粒子多相催化n- C7H16-SO2气相光化学反应的影响，并对反应的一些现象作了描述及相应的说明。 结果表明，无论有无氧化存在，ZnO粒子均能够对n-C7H16-SO2的气相光化学反应起 一定的催化作用，但是有氧气的催化活性比无氧气的高。这可能说明了ZnO的光催 化作用主要与生成的活性氧物种（O^*)有关，同时光致空穴（h^+）也能够直接引 发氧化反应；虽然ZnO纳米粒子的光催化活性随着焙烧温度的升高而降低，但是均 比商品的高。而在模拟大气的条件下，ZnO纳米粒子对n-C7H16SO2的气相光化学反 应有很大的影响，大大地促进了n-C7H16和SO2的降解，这说明ZnO纳米粒子的存在 对大气中SO2－烃的气相光化学反应的影响是不容忽视的。此外，对ZnO粒子多相催 化n-C7H16-SO2气相光化学反应的机理进行了探讨。     

用紫外-可见光检测器进行色谱峰的光谱分析方法

采用紫外－可见光检测器和自编吸收光谱分析程序对色谱峰在１９５～７００ｎｍ波长范围内进行扫描,得到样品和标准品的吸收光谱图,通过对二者进行比较来鉴定色谱峰纯度,操作简便,具有一定的实用价值。     

气质联用仪测定电子电气产品中多环芳烃

建立了以甲苯溶剂超声波震荡提取、离心机分离萃取液、气相色谱-质谱联用仪测定电子电气产品中16种多环芳烃组分的方法,萃取条件为:用甲苯溶剂在60℃超声波震荡60 min,外标法定量。各组分的浓度在10～500ng/mL范围内具有良好的线性,线性相关系数r2大于0.994,检出限为0.05～0.30 mg/kg。方法的加标回收率为80%～120%,测定结果的相对标准偏差小于5%。     

Use of computerized pattern recognition in the study of the cuticular hydrocarbons of imported fire ants. I. Introduction and characterization of the cuticular hydrocarbon patterns of Solenopsis invicta and S. richteri

A method is described in which gas chromatographic (GC) data obtained from cuticular hydrocarbons are treated by methods of pattern recognition. Based on a recently described sample preparation procedure, GC data are normalized to eliminate slight variations in chromatographic conditions and converted into the proper format for discriminant analysis by computer. The results of several methods of data treatment and display are discussed, based upon the chemometric system package, ARTHUR. The approach has the advantage of largely removing operator bias.     

Construction of an automated gas chromatography/mass spectrometry system for the analysis of ambient volatile organic compounds with on-line internal standard calibration

An automated sampling and enrichment apparatus coupled with a gas chromatography/mass spectrometry (GC/MS) technique was constructed for the analysis of ambient volatile organic compounds (VOCs). A sorbent trap was built within the system to perform on-line enrichment and thermal desorption of VOCs onto GC/MS. In order to improve analytical precision, calibration accuracy, and to safe-guard the long-term stability of this system, a mechanism to allow on-line internal standard (I.S.) addition to the air sample stream was configured within the sampling and enrichment apparatus. A sub-ppm (v/v) level standard gas mixture containing 1,4-fluorobenzene, chloropentafluorobenzene, 1-bromo-4-fluorobenzene was prepared from their pure forms. A minute amount of this I.S. gas was volumetrically mixed into the sample stream at the time of on-line enrichment of the air sample to compensate for measurement uncertainties. To assess the performance of this VOC GC/MS system, a gas mixture containing numerous VOCs at sub-ppb (v/v) level served as the ambient air sample. Various internal standard methods based on total ion count (TIC) and selective ion monitoring (SIM) modes were attempted to assess the improvement in analytical precision and accuracy. Precision was improved from 7-8% RSD without I.S. to 2-3% with I.S. for the 14 target VOCs. Uncertainties in the calibration curves were also improved with the adoption of I.S. by reducing the relative standard deviation of the slope (Sm%) by an average a factor of 4, and intercept (Sb%) by a factor of 2 for the 14 target VOCs.     

The measurement of compositions and the isotopic distribution of released fission gas in the fuel rods of pressurized water reactors (PWR) of Korea

In this work the analysis procedures of fission gas compositions and their isotopic distributions using a gas chromatography (GC) system and/or a quadrupole mass spectrometer (QMS) system were established, and their analysis results were reviewed in order to evaluate their analytical performance. Also, the accumulated data, up to now, regarding fission gas measurement were reviewed to discern any irradiation histories of the punctured fuel rods. A simple gas injection apparatus was designed and fabricated for the quantitative injection of a small volume of fission gas into the GC and the QMS system. With an appropriate temperature controlling of a molecular sieve 5A column, nitrogen, krypton and xenon of a mixture gas was clearly separated within 7 min. According to the analysis results, the relative standard deviation in the determination of fission gas compositions, krypton and xenon, by the GC analysis or by the QMS analysis was about 1%. Based on the review results of the isotopic ratios of krypton and xenon of the released fission gas, it is likely that no abnormally irradiated rods, i.e. defected rods, were included among the punctured rods.     

用于昆虫外激素研究的微量顶空收集及热解吸气相色谱进样方法初探

描述了一个结合项空气流收集与无溶剂热解吸气相色谱进样的方法。用填充PorapskQ的微量注射器作为吸附管进行气流收集。将收集物不经溶剂洗脱直接进行热解吸进样。用人工合成的昆虫外激素化合物反-7-十二碳单烯乙酸酯（E-7-DA）及顺-5,反-7-十二碳二烯乙酸酯（Z-5,E-7-DDA）测定了方法的回收率,初步探索了运用于昆虫外激素分析的可行性,并讨论了提高回收率的途径。     

Comprehensive two-dimensional gas chromatography: a powerful and versatile analytical tool

Comprehensive two-dimensional gas chromatography (GC×GC) is a novel technique which is rapidly gaining importance for the analysis of complex samples. In the present review, attention is devoted to the principle and advantages, and main characteristics such as modulation, column combinations, detector requirements and data processing, of the technique. Specifically, GC×GC of a variety of real-life samples is discussed to demonstrate the applicability of the technique, with emphasis on the usefulness of the ordered-structure principle and on the analyte-identification power provided by a combination with time-of-flight mass spectrometric detection.     

气相色谱法在线分析生物乙醇催化脱水制备乙烯的反应产物

设计并组装了在线气相色谱法测定生物乙醇脱水制备乙烯过程中的反应产物的流程和装置,被测物质包括乙烯、水、乙醛、乙醇、乙醚及丙酮。取样前应保证气态样品在保持温度为110℃以上的气体流路中畅通至少60min,进样量为1.0mL,色谱柱为填充GDX-104固定相的不锈钢柱（2m,φ4mm）,柱温为104℃。样品按规定条件通过色...