气相色谱介绍英文(绝对原创)
气相色谱仪
气相色谱仪一、气相色谱简介气相色谱（gas chromatography, GC）是一种以气体为流动相的柱色谱分离分析技术，流动相气体又称为载气（carrier gas），一般为化学惰性气体，如氮气、氦气等。
根据固定相的状态不同，可将其分为气固色谱和气液色谱。
由于在气液色谱中可供选择的固定液种类很多，容易得到好的选择性，所以有广泛的实用价值。
GC能分离气体及在操作温度下能成为气体，但又不分解的物质。
它可在极短时间内同时分离及测定多成分，并可与质谱法（MS）或红外光谱法（IR）结合使用，应用广泛。
气相色谱仪由六个基本系统组成：1. 载气系统：一般由气源钢瓶、减压装置、净化器、稳压恒流装置、压力表和流量计以及供载气连续运行的密闭管路组成。
2. 进样系统：进样就是把样品快速而定量地加到色谱柱上端，以便进行分离。
进样系统包括进样器和气化室两部分。
3. 分离系统：由色谱柱和色谱炉组成。
色谱柱可分为填充柱和毛细管柱两类。
常用的填充柱内径为2～4 mm，长1～3m，具有广泛的选择性，应用很广。
毛细管柱内径0.1～0.5mm，柱长30～300m。
毛细管柱的质量传送阻力小且管柱长，其渗透性好，分离效率高，分析速度快。
但柱容量低，进样量小，要求检测器灵敏度高，操作条件严格。
色谱炉的作用是为样品各组分在柱内的分离提供适宜的温度。
4. 温控系统：温度控制系统用来设定、控制和测量色谱炉、气化室和检测器的温度。
5. 检测系统：检测系统主要为检测器（detector），是一种能把进入其中各组分的量转换成易于测量的电信号的装置。
根据检测原理的不同可分为浓度型和质量型两类。
浓度型检测器测量的是载气中组分浓度瞬间的变化，即检测器的响应值正比于载气中组分的浓度。
如热导检测器（TCD）和电子捕获检测器（ECD。
质量型检测器测量的是载气中所携带的样品进入检测器的速度变化，即检测器的响应信号正比于单位时间内组分进入检测器的质量。
如氢焰离子化检测器（FID）和火焰光度检测器（FPD）。
第十七章气相色谱法GasChromatography
气相色谱法 是采用气体作流动相的一种
色谱法。
在此法中，载气（即流动相，它通常是一种
不与待测物作用、用来载送试样的惰性气体，
如氢气、氮气等）载着待分离的试样通过色
2. 硅藻土型载体
载体类型 : 大致可分为硅藻土和非硅藻土两类。
硅藻土载体是目前气相色谱中常用的一种载体，
它是由单细胞海藻骨架组成，主要成分是二氧 化硅和少量无机盐，根据制造方法不同，又分 为: 红色载体和白色载体
红色载体和白色载体
红色载体: 是将硅藻土与粘合剂在900℃煅烧后，
破碎过筛而得，因铁生成氧化铁呈红色，故称红色载体， 其特点是表面孔穴密集、孔径较小、比表面积较大。因 此它适宜于分析非极性或弱极性物质。
磷酸三 甲苯酯
有机皂 土
tricresyl phosphat e TCP
Bentone －34
130
二氯甲 烷、丙 酮
甲苯
＋2
弱极性物质 （醇、醛、酮
芳烃 极性化合物， 醛、酮、酯， 分离芳烃和非 芳烃 芳烃和非芳烃 分离，低级烃， 含氧化合物
200
＋4
聚乙二 polyethyl 80~200 丙酮、 氢键型 enegol 醇（ 乙醇、 氯仿 1500~ （PEG或 20000）Carbowax） ββ＇ －氧二 丙腈 oxydipropionile (ODPN) 100 甲醇、 丙酮 ＋5
第十七章 气相色谱法
Gas Chromatography
第十七章 气相色谱法
气相色谱法（GC）是英国生物化学家马丁等人在 研究液液分配色谱的基础上，于1952年创立的一 种极有效的分离方法，它可分析和分离复杂的多组 分混合物。
气相色谱名词
气相色谱词条正文(294条,56507字)1色谱法chromatography 又称色层法、层析法，是一种对混合物进行分离、分析的方式。
1903年俄国植物学家茨威特在分离植物色素时，取得了各类不同颜色的谱带，故得名色谱法。
以后此法虽慢慢应用于无色物质的分离，但“色谱”一词仍被人们沿用至今。
色谱法的原理是基于混合物中各组分在两相（一相是固定的称为固定相，另一相是流动的称为流动相）中溶解、解析、吸附、脱附，或其它作使劲的不同，当两相作相对运动时，使各组分在两相中反复多次受到上述各作使劲作用而取得相互分离。
2气相色谱法gas chromatography，GC 以气体作为流动相的色谱法。
依照所用固定相状态的不同，又可分为气-固色谱法和气-液色谱法。
前者用多孔型固体为固定相，后者那么用蒸气压低、热稳固性好、在操作温度下呈液态的有机或无机物质涂在惰性载体上（填充柱）或涂在毛细管内壁（开口管柱）作为固定相。
气相色谱法的优势是：分析速度快，分离效能高，灵敏度高，应用范围广，选择性强，分离和测定同时进行。
其局限性在于不能用于热稳固性差、蒸气压低或离子型化合物等的分析。
3反气相色谱法inverse gas chromatography (IGC) 反气相色谱法是以被测物质（如聚合物样品）作为固定相，将某种已知的挥发性低分子化合物（探针分子）作为样品注入汽化室，汽化后由载气带入色谱柱中，探针分子在气相和聚合物相两相中进行分派，由于聚合物的组成和结构的不同，与探针分子的作用也就不同，选择适合的检测器，检测探针分子在聚合物相中的保留值，藉此研究聚合物与探针分子和聚合物之间的彼此作用参数等。
在高聚物的研究中取得普遍的应用。
气相色谱法的原理和计算公式等均适用于反气相色谱法。
4超临界流体色谱法supercritical fluid chromatography 以超临界流体作为流动相（固定相与液相色谱类似）的色谱方式。
超临界流体即为处于临界温度及临界压力以上的流体，它具有对分离十分有利的物化性质，其扩散系数和黏度接近于气体，因此溶质的传质阻力较小，能够取得快速高效的分离，其密度和溶解度又与液体相似，因此可在较低的温度下分析沸点较高、热稳固性较差的物质。
英文原文及翻译
Characterization of bio-oil from induction-heating pyrolysis of food-processing sewage sludges using chromatographic analysis (可搜到原文)利用色谱法分析感应加热热解食品加工污泥中生物油特征Wen-Tien Tsai a,*, Mei-Kuei Lee b, Jeng-Hung Chang b, Ting-Yi Su b, Yuan-Ming Chang aa Graduate Institute of Bioresources, National Pingtung University of Science and Technology, Pingtung 912, Taiwanb Department of Environmental Engineering and Science, Chia Nan University of Pharmacy and Science, Tainan 717,Taiwan摘要：在这项研究中，利用气相色谱分析-质谱法(GC-MS)分析了热解生物油和来自感应加热技术热解工业污水污泥产生的气体的分数。
使用从25到500℃加热速率为300℃/min，低温冷凝氮气中的挥发分得到了液体产品。
分析结果表明：热解生物油是非常复杂的有机化合物的混合物和含有大量的氮氧化物/或含氧化合物，如脂肪烃类物质、酚类化合物、吡啶类、吡咯、胺类、酮类，等等。
目前污水污泥中的微生物含有来自蛋白质和核酸纹理的有机碳氢化合物含有氮/或氧。
不凝性挥发组分由氮氮氧化物和含氧的化合物组成，但所载小分数为酚类化合物、1H-吲哚和脂肪羧酸。
另一方面，通过气相色谱法-热导检测器（GC-TCD）进行分析得出不凝气体产品中的成分主要是二氧化碳、一氧化碳和甲烷。
关键字：污水污泥；热解油；气相色谱-质谱法介绍为了应对全球气候变暖和化石燃料价格飙升，近年来生物质资源的能源利用已引起广泛关注，因为这种替代能源将难以放出有害空气污染物（如硫氧化物和有毒重金属）和不作为化石燃料相比增加净温室气体（即CO2）排放到大气中。
气相色谱
特点：对氮、磷有高灵敏度；又名氮、磷检测器
三、 气相色谱固定相的选择 气相色谱固定相：固体固定相和液体固定相
一）、气固色谱固定相
1. 种类
(1)活性炭
(2)活性氧化铝 (3)硅胶 (4)分子筛 (5)高分子多孔微球（GDX系列）
气固色谱固定相的特点： （1）分析性能与柱的制备和活化有关； （2）同一种固定相，不同厂家或不同活化条件，分
四、 气相色谱分离条件的选择 1、 固定相的选择 2、载气种类和流速的选择
3、柱温的确定
4、柱长和柱内径的选择
5、载体的选择
6、进样方式和进样量的选择
1、 固定相的选择
①分离非极性组分非极性固定相。按沸点顺序出峰，
低沸点组分先出峰。 ② 分离极性组分用极性固定液。按极性大小顺序，极 性小的先出峰。 ③分离非极性和极性的（或易被极化的）混分离条件的重要选择参数；在气相色谱
中，气化室、色谱柱、检测器三部分在色谱仪操作时 均需控制温度； 气化室：保证液体试样瞬间气化； 检测器：保证被分离后的组分通过时不在此冷凝； 色谱柱：准确控制分离需要的温度。当试样复杂 时，分离室温度需要按一定程序控制温度变化，各组
分在最佳温度下分离；
无样品时：电桥平衡，无信号输出→直线（基线）。 有样品：气体导热系数不同，电桥失衡，有电信号输 出→曲线（色谱峰）。
3）、影响热导检测器灵敏度的因素 ①桥路电流I ： I，钨丝的温度 ，钨丝与池体之间 的温差，有利于热传导，检测器灵敏度提高。 ②池体温度：池体温度与钨丝温度相差越大，越有利
于热传导，检测器的灵敏度也就越高，但池体温度不能低
载气流速的选择
B H A C u u dH B 2 C 0 du u B uopt C
气相色谱法
气相色谱法科技名词定义中文名称：气相色谱法英文名称：gas chromatography定义：用气体作为流动相的色谱法。
用气体作为移动相的色谱法。
根据所用固定相的不同可分为两类：固定相是固体的，称为气固色谱法；固定相是液体的则称为气液色谱法。
目录简介拼音英文参考定义对仪器的一般要求原理发展简史仪器装置和操作气流系统分离系统检测系统数据处理系统温度控制系统及其他辅助部件流动相固定相操作温度样品预处理分类内标准法绝对标准曲线法峰面积百分率法定性和定量分析综述定性分析定量分析应用优缺点优点缺点展望gas phase chromatography定义：气相色谱法（gas chromatography 简称GC）是色谱法的一种。
色谱法中有两个相，一个相是流动气相色谱图相，另一个相是固定相。
如果用液体作流动相，就叫液相色谱，用气体作流动相，就叫气相色谱。
气相色谱法由于所用的固定相不同，可以分为两种，用固体吸附剂作固定相的叫气固色谱，用涂有固定液的担体作固定相的叫气液色谱。
按色谱分离原理来分，气相色谱法亦可分为吸附色谱和分配色谱两类，在气固色谱中，固定相为吸附剂，气固色谱属于吸附色谱，气液色谱属于分配色谱。
按色谱操作形式来分，气相色谱属于柱色谱，根据所使用的色谱柱粗细不同，可分为一般填充柱和毛细管柱两类。
一般填充柱是将固定相装在一根玻璃或金属的管中，管内径为2～6毫米。
毛细管柱则又可分为空心毛细管柱和填充毛细管柱两种。
空心毛细管柱是将固定液直接涂在内径只有0.1～0.5毫米的玻璃或金属毛细管的内壁上，填充毛细管柱是近几年才发展起来的，它是将某些多孔性固体颗粒装入厚壁玻管中，然后加热拉制成毛细管，一般内径为0.25～0.5毫米。
在实际工作中，气相色谱法是以气液色谱为主。
对仪器的一般要求：所用的仪器为气相色谱仪。
除另有规定外，载气为氮气；色谱柱为填充柱或毛细管柱，填充柱的材质为不锈钢或玻璃，载体用直径为0.25～0.18mm 、0.18～0.15mm或0.15～0.125mm经酸洗并硅烷化处理的硅藻土或高分子多孔小球；常用玻璃或弹性石英毛细管柱的内径为0.20或0.32mm。
气相色谱仪单词
积分型检测器integrating detector激光光热检测器laser and light heat detector激光解吸质谱法laser desorption MS，LDMS激光裂解器laser pyrolyzer激光色谱laser chromatography激光诱导光热光偏转测量detection of laser-induced light heat…激光诱导光束干涉检测detection of laser-induced light beam I…激光诱导毛细管振动测量laser-reduced capillary vibration det…激光诱导荧光检测器laser-induced fluorescence detector记忆峰memory peak记忆效应memory effect夹层槽sandwich chamber假峰ghost peak间断洗脱色谱法interrupted-elution chromatography间接光度（检测）离子色谱法indirect photometric io n chromato… 间接光度（检测）色谱法indirect photometric chromatography间接检测indirect detection间接荧光检测indirect fluorescence detection间接紫外检测indirect ultraviolet detection检测器detector检测器检测限detector detectability检测器灵敏度detector sensitivity检测器线性范围detector linear range碱火焰电离检测器alkali flame ionization detector，AFID碱洗法alkali wash剪纸称重法cut-paper weighing method减尾剂tailing reducer减压液相色谱vacuum liquid chromatography键合固定相bonded stationary phase键合型离子交换剂bonded ion exchanger焦耳热joule heating胶束薄层色谱法micellar thin layer chromatography胶束液相色谱法micellar liquid chromatography交联度crosslinking degree阶梯梯度stagewise gradient介电常数检测器dielectric constant detector金属配合物离子色谱法metal complex ion chromatography，MCIC 金属氧化物固定相metal oxides stationary phase金属作用色谱metal interaction chromatography进样阀injection valve进样量sample size进样器injector静态顶空分析法static headspace analysis静态涂渍法static coating method径流柱radial flow column径向流动色谱radial flow chromatography径向压缩柱radial compression column径向展开法radial development径向展开色谱radial development chromatography净保留体积net retention volume居里点裂解器Curie point pyrolyzer矩形池rectangle form pool聚苯乙烯PS/DVB聚硅氧烷高温裂解去活high-temperature pyrolysis deactivation… 聚合物基质离子交换剂polymer substrate ion exchanger绝对检测器absolute detector开口分流open split开口管柱open tubular column可见光检测器visible light detector可交换离子exchangable ion空间性谱带加宽band broadening in space空穴色谱法vacancy chromatography孔结构pore structure孔径pore diameter孔径分布pore size distribution控制单元control unit快速色谱法high-speed chromatography离心逆流色谱centrifugal counter-current chromatography离心制备薄层色谱法centric-preparation TLC离子对色谱法ion pair chromatography，IPC离子对试剂ion pair reagent离子对探针检测ion-pairing probes detection离子对形成模型ion pair formation model离子交换电动色谱ion-exchange electrokinetic chromatography 离子交换剂ion exchanger离子交换毛细管电色谱ion exchange capillary electrokinetic离子交换膜ion exchange membrane离子交换色谱法ion exchange chromatography，IEC离子交换树脂ion exchange resin离子交换位置ion exchange site离子交换柱ion exchange column离子排斥色谱法ion exclusion chromatography，ICE离子色谱法ion chromatography，IC离子色谱仪ion chromatograph离子相互作用模型ion interaction model离子相互作用色谱法ion interaction chromatography，IIC离子抑制色谱法ion suppression chromatography，ISC理论塔板高度height equivalent to a theoretical plate（HETP）理论塔板数number of theoretical plates两性电解质ampholytes两性离子zwitter-ion两性离子交换剂zwitterion exchanger裂解气相色谱法pyrolysis gas chromatography PyGC临界胶束浓度critical micelle concentration淋洗剂eluent淋洗离子eluent ion淋洗色谱法elution chromatography馏分收集器fraction collector流动池flow cell电离截面检测器ionization cross section detector电歧视效应the effect of electrical discrimination电迁移进样electrophoretic injection电渗流electroendosmotic flow电渗流标记物electroendosmotic flow marker电渗流淌度electroendosmotic mobility电位检测器electricity potential detector电泳淌度electrophoretic mobility电子俘获检测器electron capture detector电子迁移率检测器electron mobility detector调整保留时间adjusted retention time调整保留体积adjusted retention volume叠加内标法added internal standard method顶空气相色谱法headspace gas chromatography，GC-HS顶替法displacement development顶替色谱法displacement chromatography动态包覆dynamic coating动态分离dynamic separatio动态复合离子交换模型dynamic complex ion exchange model动态改性dynamic modification动态离子交换模型dynamic ion exchange model动态涂渍dynamic coating动态涂渍法dynamic coated method动态脱活dynamic de-activity短柱色谱法short column chromatography堆积硅珠stacked silica bead堆积性能bulk property多次反射池multi-reflect pool多分散度polydispersity多功能基离子交换剂multi-functional group ion exchanger多角度激光光散射光度计multi-angle laser light scattering ph…多孔层开口管柱porous layer open tubular column，PLOT多孔高聚物PLOT柱porous polymer beads PLOT column多孔硅胶porous silica gel多孔聚合物气液固色谱柱porous polymer beads GLS column GLS 多孔石墨碳porous graphitic carbon，PGC多孔载体porous support多脉冲实验multiple pulse experiments多维色谱法multi-dimensional chromatography多维色谱仪multidimensional chromatograph多用色谱仪unified chromatograph惰性气体鼓泡吹扫脱气sweeping degas by inert gas二次化学平衡secondary chemical equilibria ，SCE二极管阵列检测器diode-array detector，DAD二维色谱法two-dimensional chromatography二元溶剂体系dual solvent system反冲洗back wash反吹技术back flushing technique反峰negative peak反离子counter ion反气相色谱法inverse gas chromatography （IGC）反相高效液相色谱法reversed phase high performance liquid ch… 反相离子对色谱reversed phase ion pair chromatography反相离子对色谱法reversed phase ion-pair chromatography反相毛细管电色谱reverse capillary electrokinetic chromatogr…反相柱reversed phase column反应气相色谱法reaction gas chromatography反应色谱reaction chromatography反圆心式展开anti-circular development反转电渗流reverse electroendosmotic flow范第姆特方程式van Deemter equation仿生传感器Biomimic electrode放射性电离检测器radio ionization detector放射性检测器radioactivity detector放射自显影autoradiography非极性固定相non-polar stationary phase非极性键合相non-polar bonded phase非金属离子传感器non-metal ion sensor非水系凝胶色谱柱non-aqua-system gel column非水相色谱nonaqueous phase chromatography非吸附性载体non-adsorptive support非线性分流non-linearity split stream非线性色谱non-linear chromatography非线性吸附等温线non-linear adsorption isotherm非抑制型电导检测non-suppressed conductance detection非抑制型离子色谱法non-suppressed ion chromatography，NSIC 费尔盖特效益Fellgett advantage酚醛离子交换树脂phenolic ion exchange resin分离－反应－分离展开SRS development分离数separation number分离因子separation factor分离柱separation column分流split stream分流比split ratio分流进样法split sampling分流器splitter分配等温线distribution isotherm分配色谱partition chromatography分配系数partition coefficient分析型色谱仪analytical type chromatograph分子扩散molecular diffusion分子量分布molecular weight distribution分子量检测器molecular weight detector分子筛molecular sieve分子筛色谱molecular sieve chromatography分子吸附molecular adsorption分子吸收光谱molecular absorption spectroscopy 封尾endcapping峰高peak height。
气相色谱法gaschromatographyppt课件
步骤
先对已知物进行色谱分析，记录其 色谱峰的保留时间和峰形；再对未 知物进行色谱分析，比较两者的保 留时间和峰形是否一致。
注意事项
需确保实验条件一致，如温度、流 速等，以获得准确的比较结果。
定量分析
原理
注意事项
通过测量色谱峰的峰高或峰面积，计 算待测物的浓度。
需确保进样量准确，以获得准确的测 量结果。
操作规范
严格按照仪器操作规程进 行实验操作，避免因操作 不当引起的安全事故。
06
气相色谱法的应用实例
环境气体分析
总结词
气相色谱法在环境气体分析中具有重要作用，能够检测和分离大气中的有害气体和温室气体。
详细描述
气相色谱法通过将气体样品导入色谱柱，利用不同气体在柱内的吸附或溶解性能差异实现分离，再通过检测器检 测各组分的浓度。这种方法广泛应用于大气中温室气体（如二氧化碳、甲烷等）的监测以及工业废气中有害气体 的检测。
类型
常用的检测器有热导检测器、氢火焰离子化检测器、电子捕获检测器、氮磷检测器等。
工作原理
热导检测器是根据组分与载气热导率不同的原理制成的；氢火焰离子化检测器是根据有机物在氢火焰中 燃烧产生离子流的原理制成的；电子捕获检测器则是依据电负性强的物质在电子捕获检测器中产生电信 号的原理进行工作的。
进样系统
气相色谱法Gas Chromatography PPT课件
• 气相色谱法简介 • 气相色谱法的基本组成 • 气相色谱法的操作流程 • 气相色谱法的实验技术 • 气相色谱法的实验技巧与注意事项 • 气相色谱法的应用实例
01
气相色谱法简介
定义与原理
定义
气相色谱法是一种分离和分析复 杂混合物中各组分的方法。
专业英语翻译-气相色谱
4
Successful chromatography may require conversion of the drug to a less polar and more volatile derivative by treatment of reactive groups with appropriate reagents . 【下划线部分为填空考点】
稳定为止。
columns n. 柱 ；栏目 ；专栏（column的复数） conditioned adj. 有条件的，受制约的；习惯于…的
v. 使适应（condition的过去分词）；以…为条件 baseline n. 基线；底线 characteristics n. 特性，特征；特色；特质
2
This may be done by operation at a temperature above that called for by the method or by repeated injections of the compound or mixture to be chromatographed.
气相色谱 Gas Chromatography
课本94页第四段 主讲人：XX
1
Packed columns must be conditioned before use until the baseline and other charactetistics are stable.
色谱柱在使用前必须进行调整，直到基线和其他性能
成功的色谱分析可能需要通过用适当的试剂处理活性
基团，将药物转化为低极性、高挥发性的衍生物。
色谱术语英文
积分型检测器 integrating detector激光光热检测器 laser and light heat detector激光解吸质谱法 laser desorption MS， LDMS激光裂解器 laser pyrolyzer激光色谱 laser chromatography激光诱导光热光偏转测量 detection of laser-induced light heat…激光诱导光束干涉检测 detection of laser-induced light beam I…激光诱导毛细管振动测量 laser-reduced capillary vibration det…激光诱导荧光检测器 laser-induced fluorescence detector记忆峰 memory peak记忆效应 memory effect夹层槽 sandwich chamber假峰 ghost peak间断洗脱色谱法 interrupted-elution chromatography间接光度（检测）离子色谱法 indirect photometric ion chromato…间接光度（检测）色谱法 indirect photometric chromatography 间接检测 indirect detection间接荧光检测 indirect fluorescence detection间接紫外检测 indirect ultraviolet detection检测器 detector检测器检测限 detector detectability检测器灵敏度 detector sensitivity检测器线性范围 detector linear range碱火焰电离检测器 alkali flame ionization detector， AFID碱洗法 alkali wash剪纸称重法 cut-paper weighing method减尾剂 tailing reducer减压液相色谱 vacuum liquid chromatography键合固定相 bonded stationary phase键合型离子交换剂 bonded ion exchanger焦耳热 joule heating胶束薄层色谱法 micellar thin layer chromatography胶束液相色谱法 micellar liquid chromatography交联度 crosslinking degree阶梯梯度 stagewise gradient介电常数检测器 dielectric constant detector金属配合物离子色谱法 metal complex ion chromatography， MCIC 金属氧化物固定相 metal oxides stationary phase金属作用色谱 metal interaction chromatography进样阀 injection valve进样量 sample size进样器 injector静态顶空分析法 static headspace analysis静态涂渍法 static coating method径流柱 radial flow column径向流动色谱 radial flow chromatography径向压缩柱 radial compression column径向展开法 radial development径向展开色谱 radial development chromatography净保留体积 net retention volume居里点裂解器 Curie point pyrolyzer矩形池 rectangle form pool聚苯乙烯 PS/DVB聚硅氧烷高温裂解去活 high-temperature pyrolysis deactivation…聚合物基质离子交换剂 polymer substrate ion exchanger绝对检测器 absolute detector开口分流 open split开口管柱 open tubular column可见光检测器 visible light detector可交换离子 exchangable ion空间性谱带加宽 band broadening in space空穴色谱法 vacancy chromatography孔结构 pore structure孔径 pore diameter孔径分布 pore size distribution控制单元 control unit快速色谱法 high-speed chromatography离心逆流色谱 centrifugal counter-current chromatography离心制备薄层色谱法 centric-preparation TLC离子对色谱法 ion pair chromatography， IPC离子对试剂 ion pair reagent离子对探针检测 ion-pairing probes detection离子对形成模型 ion pair formation model离子交换电动色谱 ion-exchange electrokinetic chromatography 离子交换剂 ion exchanger离子交换毛细管电色谱 ion exchange capillary electrokinetic离子交换膜 ion exchange membrane离子交换色谱法 ion exchange chromatography， IEC离子交换树脂 ion exchange resin离子交换位置 ion exchange site离子交换柱 ion exchange column离子排斥色谱法 ion exclusion chromatography， ICE离子色谱法 ion chromatography， IC离子色谱仪 ion chromatograph离子相互作用模型 ion interaction model离子相互作用色谱法 ion interaction chromatography， IIC离子抑制色谱法 ion suppression chromatography， ISC理论塔板高度 height equivalent to a theoretical plate（HETP）理论塔板数 number of theoretical plates两性电解质 ampholytes两性离子 zwitter-ion两性离子交换剂 zwitterion exchanger裂解气相色谱法 pyrolysis gas chromatography PyGC临界胶束浓度 critical micelle concentration淋洗剂 eluent淋洗离子 eluent ion淋洗色谱法 elution chromatography馏分收集器 fraction collector流动池 flow cell电离截面检测器 ionization cross section detector电歧视效应 the effect of electrical discrimination电迁移进样 electrophoretic injection电渗流 electroendosmotic flow电渗流标记物 electroendosmotic flow marker电渗流淌度 electroendosmotic mobility电位检测器 electricity potential detector电泳淌度 electrophoretic mobility电子俘获检测器 electron capture detector电子迁移率检测器 electron mobility detector调整保留时间 adjusted retention time调整保留体积 adjusted retention volume叠加内标法 added internal standard method顶空气相色谱法 headspace gas chromatography， GC-HS顶替法 displacement development顶替色谱法 displacement chromatography动态包覆 dynamic coating动态分离 dynamic separatio动态复合离子交换模型 dynamic complex ion exchange model动态改性 dynamic modification动态离子交换模型 dynamic ion exchange model动态涂渍 dynamic coating动态涂渍法 dynamic coated method动态脱活 dynamic de-activity短柱色谱法 short column chromatography堆积硅珠 stacked silica bead堆积性能 bulk property多次反射池 multi-reflect pool多分散度 polydispersity多功能基离子交换剂 multi-functional group ion exchanger多角度激光光散射光度计 multi-angle laser light scattering ph…多孔层开口管柱 porous layer open tubular column，PLOT多孔高聚物PLOT柱 porous polymer beads PLOT column多孔硅胶 porous silica gel多孔聚合物气液固色谱柱 porous polymer beads GLS column GLS多孔石墨碳 porous graphitic carbon， PGC多孔载体 porous support多脉冲实验 multiple pulse experiments多维色谱法 multi-dimensional chromatography多维色谱仪 multidimensional chromatograph多用色谱仪 unified chromatograph惰性气体鼓泡吹扫脱气 sweeping degas by inert gas二次化学平衡 secondary chemical equilibria ，SCE二极管阵列检测器 diode-array detector， DAD二维色谱法 two-dimensional chromatography二元溶剂体系 dual solvent system反冲洗 back wash反吹技术 back flushing technique反峰 negative peak反离子 counter ion反气相色谱法 inverse gas chromatography （IGC）反相高效液相色谱法 reversed phase high performance liquid ch…反相离子对色谱 reversed phase ion pair chromatography反相离子对色谱法 reversed phase ion-pair chromatography反相毛细管电色谱 reverse capillary electrokinetic chromatogr…反相柱 reversed phase column反应气相色谱法 reaction gas chromatography反应色谱 reaction chromatography反圆心式展开 anti-circular development反转电渗流 reverse electroendosmotic flow范第姆特方程式 van Deemter equation仿生传感器 Biomimic electrode放射性电离检测器 radio ionization detector放射性检测器 radioactivity detector放射自显影 autoradiography非极性固定相 non-polar stationary phase非极性键合相 non-polar bonded phase非金属离子传感器 non-metal ion sensor非水系凝胶色谱柱 non-aqua-system gel column非水相色谱 nonaqueous phase chromatography非吸附性载体 non-adsorptive support非线性分流 non-linearity split stream非线性色谱 non-linear chromatography非线性吸附等温线 non-linear adsorption isotherm非抑制型电导检测 non-suppressed conductance detection非抑制型离子色谱法 non-suppressed ion chromatography， NSIC 费尔盖特效益 Fellgett advantage酚醛离子交换树脂 phenolic ion exchange resin分离－反应－分离展开 SRS development分离数 separation number分离因子 separation factor分离柱 separation column分流 split stream分流比 split ratio分流进样法 split sampling分流器 splitter分配等温线 distribution isotherm分配色谱 partition chromatography分配系数 partition coefficient分析型色谱仪 analytical type chromatograph分子扩散 molecular diffusion分子量分布 molecular weight distribution分子量检测器 molecular weight detector分子筛 molecular sieve分子筛色谱 molecular sieve chromatography分子吸附 molecular adsorption分子吸收光谱 molecular absorption spectroscopy封尾 endcapping峰高 peak height。
气相色谱
mM Rs mM mS
（2-11）
1 1 m 1 k 1 S mM
组分和流动相通过长度为L的色谱柱所需时间分别
L tR us
(2 13)
tM
L u
(2 14)
推导：t R t M (1 k )
' tR tM tR k tM tM
iii 峰低宽度（peak width at base）Y 自色谱峰两侧的转折点所作切线在基线上的截距IJ 与标准偏差的关系为： Y=4σ
利用色谱流出曲线可以解决以下问题： i 根据色谱峰位置（保留值）可以进行定性检测； ii 根据色谱峰面积或峰高可以进行定量测定； iii 根据色谱峰位置及宽度可以对色谱柱分离情况 进行评价。
8、调整保留体积（adjusted retention volume）
VR’=tR’F0 或 VR’=VR-Vm
VR’与载气流速无关
9、相对保留值（relative retention volume）r
指某组分2的调整保留值与另一组分1的调整 保留值之比。
r21
t
t
' R ( 2) ' R (1)
n有效
' ' tR tR 2 5.54( ) 16( ) 2 Y1 / 2 Y
(2 18) (2 19)
H 有效
L n有效
有效塔板数和有效塔板高度较为真实的反应了柱效能的 好坏。 成功处：解释流出曲线的形状（呈正态分布）、浓度极大点 的位置以及计算评价柱效能等方面。 不足处：基本假设是不当 。
氦气和氩气。
气路结构:主要有两种气路形式
单柱单气路，适用于恒温分析 双柱双气路，适用于程序升温，并能补偿固 定液的流失使其基线稳定。
气相色谱法(gas chromatography,GC)
短，两者的乘积不变。在理论上VR要比
tR准确，但测量VR没有测量tR方便。
（2）死体积VM（dead volume） 是
指不与固定相作用的惰性物质通过色谱 柱后出峰时所需的载气体积。也就是从
样进器经色谱柱到检测器出口的流路中，
由气相所占有的体积。即
线相交部分的宽度。
W
在理想状态下，色谱峰呈正态分布。根 据正态分布曲线的特征，在两拐点之间的距
离（此处峰高为0.607 h）为两倍标准偏差
（）
W0.607h 2
Wh / 2 2 2 ln 2
W 4
色谱峰宽度是衡量色谱柱分离效能
的参数。标准偏差 的大小表示经色谱 柱分离后组分流出色谱柱的分散程度。
（四）色谱峰区域宽度
半峰宽Wh/2 （peak width at half height）
即色谱峰高一半处的宽度，又称半高峰宽。
Wh/2
h h/2
基线宽度Wb（peak width at the baseline） 又称峰底宽度（peak width at the base），
是通过色谱峰两侧的拐点所作的切线与基
气相色谱仪由五部分组成 1．载气系统 包括气源、气体净化和 气体流速控制等装置。
2．进样系统 包括进样器、气化室和
温控装置。
3．分离系统 包括色谱柱、柱箱和温
控装置。
4．检测系统 包括检测器和温控装置。 5．记录系统 包括放大器、数据处理
装置及记录仪。
6 2
8
9 10
13
3 5 7
1
11
4
12
14
力有关。
Agilent 气相色谱基本原理(英文版)
Identify - Qualitative - What is it? Measure - Quantitative - How much?
6850/90 - SPLIT/SPLITLESS CAPILLARY INLET Capillary Column Stationary Phases
S P tn e a h tr s i y o s a a
Fundamentals of Gas Chromatography
Updated Sept 27, 2001
On the Agilent Web @ /fgc_cbt/agilent/welcome.htm
Fundamentals of Gas Chromatography Components of a GC System
TANK PRIMARY PRESSURE - 2000 PSI SECONDARY - 100 PSI
COLUMN OVEN TEMPERATURE
50O C
COLUMN FLOW PROPORTIONAL TO INJECTION PORT PRESserted into Injection Port
AO PN PS L II C A T H P P H A P S O E L S A R I T YTG EE M P R A N a y oie mae i , rb t s no , c ec p , s r h ni d sd s H P 1 n o n p o l a r -3 6 0 t5 o 2 P o cn Cs o s B ,u u sl l m , n rp pu o h f e s d ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------a,gs lo s , kd M auE l s, i rF d A H Sn P -5 ,5 n H P Mp o o l a r -3 63 00 t5 o 2 / 0 ht o s a du ln p o cn g m e a o e d , ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------a l oc rros o hte c l, l e o si s , i s ap c d H P 1 3 l ti o - 2 0 o 1 wl oa 2 m d p r 0 t0 o 8 , sle Vo Om A r , y c o p ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------aa e rr i , te o ni s c e i, l, s d o s p m s c H P 3 5 i ri na te e m d t e 43 00 t0 o 3 2 / 0 pu ht ai r m a c e c a l s ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ahsi , rrr e d o be c i ,te l, c s o i ps s di e c H P 1 7 0 1 ira nt te e m d i e -2 2 0 t0 o 8 Tr M S s u g a s ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------d c ted rg e s ul s t s gsi , o s, i s , oce l y p di r H P 5 0 + i ri na te e m d t e 32 06 t0 o 2 8 / 0 -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------Fdar r A o sl o M eu l Ec e s H sl t ,t t ,t a t l a i e s ne a P 2 2 5 i ri na te e m d t e 42 02 t0 o 2 4 / 0 ------- ------------------ ------------------ ------------------ ------------------ ------------------ ------------------ ------------------ ------------------ ----------------- ----------ao e c hh i a as do y s ll d , l s e c d , , H P F F A P p o l a r 6F 0 F t0 oA 2, 4 P a k,i c ei s rse y ts l ,o l a ne t e n t r -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------a fa m l oc a c ri a , o ert h le o s d i , s c , s Hx p P -Wl I N N O a o a r 42 , 04 t 02 o B 2P 6/ 0 0 eo s i sl e n t s i a l -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------s, o o o l ll l l tyc v co e s s n ,h s a g H P Wp a x o l a r 22 03 t0 o 2 5 / 0
气相色谱法lecture3
Fraction 5 Fraction 5
常用毛细管色谱柱固定液
固定液
极性 适用范围
100％二甲基聚硅 氧烷
(50％三氟丙基)甲 基聚硅氧烷
聚乙二醇
非极性
脂肪烃化合物， 石化产品
中等极性 极性化合物，如 高级脂肪酸
中强极性 极性化合物，如 醇、羧酸酯等
2 气固色谱固定相
分离对象
永久性气体 惰性气体 低沸点有机化合物
Si O Si
+ HCl
二甲基 二氯硅
烷
2) 固定液－高沸点的有机化合物
对固定液的要求
a. 热稳定性好，在操作温度下不发生聚合、分 解等反应；具有较低的蒸气压，以免流失。
b. 化学稳定性好，不与样品或载气发生不可逆 的化学反应。
c. 粘度和凝固点低，以便在载体表面能均匀分 布。
d. 对样品中的各组分有适当的溶解度。(填充 柱 1.15，毛细管柱 1.08 )
柱温升高， K 减小，分离度
下降。
但同时又会加剧纵 向扩散，从而导致
柱效下降。
降低柱温，分析 时间增加
选择原则
1. 柱温应控制在固定液的最高使用温度和 最低使用温度范围之内。
2. 使最难分离的组分有尽可能好的分离前 提下，采取适当低的柱温，但以保留时 间适宜，峰形不拖尾为度。
3. 柱温一般选择在组分平均沸点左右。
1. 色谱柱
固定相； 固定液液膜厚度；
柱长等
2. 载气及其线速的选择
流动相线速度对塔板高度的影响 流速高时： 传质阻力项是影响柱效的主要 因素，流速，柱效。 流速低时： 分子扩散项成为影响柱效的主 要因素，流速,柱效 。
H = A + B/u + C·u
气相色谱质谱名词说明[新版]
![气相色谱质谱名词说明[新版]](https://img.taocdn.com/s3/m/5d8eeb3ccdbff121dd36a32d7375a417866fc111.png)
1.气相色谱Gas chromatography用气体作为流动相的色谱法。
它利用物质在流动相中与固定相中分配系数的差异，当两者作相对运动时，试样组分在两相之间进行反复多次分配，各组分的分配系数即使只有微小差别，随着流动相（气体）的移动也可以有距离，最后被测样品组分得到分离测定。
3.汽化室Vaporizer使试样瞬时汽化并预热载气的部件4.进样器Sample injector能定量和瞬时地将试样注入色谱系统的部件，通常指注射器、进样阀或自动进样器。
5.EPC6.相Phase、固定相stationary phase和流动相mobile phase一个体系中的某一均匀部分称为相；在色谱分离过程中，固定不动的一相称为固定相；通过或沿着固定相移动的流体称为流动相。
7.色谱柱Chromatography Column內有固定相用以分离样品組分的柱管。
8.填充柱Packed Column填充固定相的色谱柱。
9.毛細管柱Caplliary Column内径一般为0.1-0.5mm的色谱柱。
10.分流比Split Ratio样品载气化时中完全气化并与载气充分混合后，一部分进入柱內，其余的放空，这两部分载气量的比值11.色谱峰chromatographic peak色谱柱流出物通过检测器系统时产生的响应信号的微分曲线。
12.基线base line在正常操作条件下，仅有载气通过检测器系统时所产生的响应信号的曲线。
13.基线噪声baseline noise由于各种因素引起的基线波动。
14.基线漂移baseline drift基线随时间定向的缓慢变化。
15.峰面积peak area流出曲线（色谱峰）与基线构成之面积称峰面积，用Ａ表示。
16.保留时间Retention time溶质自进入色谱柱至峰最高处所需的时间。
17.保留体积Retention Volume溶质进入谱柱至峰最高处所需的流动相体积。
18.死时间Dead time在柱上不保留的组分或杂质所形成峰的保留时间。
气相色谱英文
From Wikipedia, the free encyclopedia
*DV FKURPDWRJUDSK\ *& , is a common type of chromatography used in analytical chemistry for separating and analyzing compounds that can be vaporized without decomposition. Typical uses of GC include testing the purity of a particular substance, or separating the different components of a mixture (the relative amounts of such components can also be determined). In some situations, GC may help in identifying a compound. In preparative chromatography, GC can be used to prepare pure compounds from a mixture.[1][2] In gas chromatography, the PRELOH SKDVH (or "moving phase") is a carrier gas, usually an inert gas such as helium or an unreactive gas such as nitrogen. The VWDWLRQDU\ SKDVH is a microscopic layer of liquid or polymer on an inert solid support, inside a piece of glass or metal tubing called a column (an homage to the fractionating column used in distillation). The instrument used to perform gas chromatography is called a JDV FKURPDWRJUDSK (or "aerograph", "gas separator").
气相色谱基础英文图文介绍
IntroductionGas chromatography - specifically gas-liquid chromatography - involves a sample being vapourised and injected onto the head of the chromatographic column. The sample is transported through the column by the flow of inert, gaseous mobile phase. The column itself contains a liquid stationary phase which is adsorbed onto the surface of an inert solid.Have a look at this schematic diagram of a gas chromatograph:Instrumental componentsCarrier gasThe carrier gas must be chemically inert. Commonly used gases include nitrogen, helium, argon, and carbon dioxide. The choice of carrier gas is often dependant upon the type of detector which is used. The carrier gas system also contains a molecular sieve to remove water and other impurities.Sample injection portFor optimum column efficiency, the sample should not be too large, and should be introduced onto the column as a "plug" of vapour - slow injection of large samples causes band broadening and loss of resolution. The most common injection method is where a microsyringe is used to inject samplethrough a rubber septum into a flash vapouriser port at the head of the column. The temperature of the sample port is usually about 50︒C higher than the boiling point of the least volatile component of the sample. For packed columns, sample size ranges from tenths of a microliter up to 20 microliters. Capillary columns, on the other hand, need much less sample, typically around 10-3μL. For capillary GC, split/splitless injection is used. Have a look at this diagram of a split/splitless injector;The injector can be used in one of two modes; split or splitless. The injector contains a heated chamber containing a glass liner into which the sample is injected through the septum. The carrier gas enters the chamber and can leave by three routes (when the injector is in split mode). The sample vapourises to form a mixture of carrier gas, vapourised solvent and vapourised solutes. A proportion of this mixture passes onto the column, but most exits through the split outlet. The septum purge outlet prevents septum bleed components from entering the column.ColumnsThere are two general types of column, packed and capillary (also known as open tubular). Packed columns contain a finely divided, inert, solid support material (commonly based on diatomaceous earth) coated with liquid stationary phase. Most packed columns are 1.5 - 10m in length and have an internal diameter of 2 - 4mm.Capillary columns have an internal diameter of a few tenths of a millimeter. They can be one of two types; wall-coated open tubular (WCOT) or support-coated open tubular (SCOT). Wall-coated columns consist of a capillary tube whose walls are coated with liquid stationary phase. In support-coated columns, the inner wall of the capillary is lined with a thin layer of support material such as diatomaceous earth, onto which the stationary phase has been adsorbed. SCOT columns are generally less efficient than WCOT columns. Both types of capillary column are more efficient than packed columns.In 1979, a new type of WCOT column was devised - the Fused Silica Open Tubular (FSOT) column;These have much thinner walls than the glass capillary columns, and are given strength by the polyimide coating. These columns are flexible and can be wound into coils. They have the advantages of physical strength, flexibility and low reactivity.Column temperatureFor precise work, column temperature must be controlled to within tenths of a degree. The optimum column temperature is dependant upon the boiling point of the sample. As a rule of thumb, a temperature slightly above the average boiling point of the sample results in an elution time of 2 - 30 minutes. Minimal temperatures give good resolution, but increase elution times. If a sample has a wide boiling range, then temperature programming can be useful. The column temperature is increased (either continuously or in steps) as separation proceeds.DetectorsThere are many detectors which can be used in gas chromatography. Different detectors will give different types of selectivity. Anon-selective detector responds to all compounds except the carrier gas, a selective detector responds to a range of compounds with a common physical or chemical property and a specific detector responds to a single chemical compound. Detectors can also be grouped into concentration dependant detectors and mass flow dependant detectors. The signal from a concentration dependant detector is related to the concentration of solute in the detector, and does not usually destroy the sample Dilution of with make-up gas will lower the detectors response. Mass flow dependant detectors usually destroy the sample, and the signal is related to the rate at which solute molecules enter the detector. The response of a mass flow dependant detector is unaffected by make-up gas. Have a look at this tabular summary of common GC detectors:The effluent from the column is mixed with hydrogen and air, and ignited. Organic compounds burning in the flame produce ions and electrons which can conduct electricity through the flame. A large electrical potential is applied at the burner tip, and a collector electrode is located above the flame. The current resulting from the pyrolysis of any organic compounds is measured. FIDs are mass sensitive rather than concentration sensitive; this gives the advantage that changes in mobile phase flow rate do not affect the detector's response. The FID is a useful general detector for the analysis of organic compounds; it has high sensitivity, a large linear response range, and low noise. It is also robust and easy to use, but unfortunately, it destroys the sample.Gas Chromatography: Procedure(1) Add the sample to be injected to the syringe.A 25µL glass Hamilton syringe is used to i nject the GC samples. Only 2-4µL of sample is injected onto the column, which means that you fill onlya small part of the barrel with sample. Examine the syringe carefullybefore you fill it. The divisions are marked "5 - 10 - 15 - 20 - 25".This is a 25 µL glass Hamilton syringe. You only inject 2.5µL, so it will NOT be filled to the top.Click on the photo to see an enlargement.Place the tip of the needle in the liquid. Slowly draw up a small amountof liquid by raising the plunger, then press on the plunger to expel theliquid back into the liquid. This serves to “rinse” the syringe withyour sample, ensuring that what you will measure in the GC run is thecomposition of your mixture. Repeat the rinse process one or two times.Then, draw up the plunger slowly again while the needle is in the liquidand carefully f ill the syringe with liquid about halfway to the “5”.It is often hard to see the liquid in the syringe.If the syringe is clogged, the plunger will be inthe correct position but the barrel of the syringewill be filled with only air, as in the bottomsyringe in the photo to the left.The best thing to do is to carefullyexaming the syringe after you thinkthat you have filled it. Hold it upto the light to get a better view.Small air bubbles in the syringewill not affect the GC run (middlesyringe in the photo to the left).As long as there is enough liquid inthe syringe, the GC run will workfine. If you keep getting bubbles,just pull the plunger up a bit pastthe "halfway to the 5" mark tocompensate.If you have a VERY large air bubble,you will not have enough liquid toshow a reading on the GC (e.g., thebottom syringe in the photo).(2) Inject the sample into the injector port.You are need to do two things sequentially and quickly, so make sure you know where the injection port is and where the start button on the recorderis.Push the needle of the syringe through the injection port and immediately press the plunger to inject the sample, then immediately press the start button on the recorder.You will feel a bit of resistance from the rubber septum in the injection port; this is to be expected and you should be prepared to apply some pressure to the syringe as you force the needle into the instrument allthe way to the base of the needle.(Click on each of the photos below for a larger view.)Push the needle of thefilled syringe through theinjector (as far as it willgo) and quickly push theplunger.Remove the syringeimmediately . . .. . . and quickly press thestart button on theintegrating recorder orthe start recording buttonon the computer (askyour TA which device isconnected to the GC thatyou are using)Here's a close-up ofthe integratingrecorder.Here's a series of picturesshowing how to run thecomputer program.(3) Sit back and wait.Observe the recorder. Within several minutes, it should record several peaks.(4) End the GC run.When you have seen all of the peaks which you suspect are in the mixture,or when the recorder has shown a flat baseline for a few minutes or so,press stop on the recorder.When you press stop, the recorder will print out the peaks, the retentiontimes, and the areas under the peaks. When it is done printing, you canpress “enter” a couple times to advance the paper.Carefully tear the paper off the recorder. The paper is not perforated, so do not try to pull up and expect it to pop out of the recorder. Instead, pull it down to start a tear from one edge, and then continue the tear until the paper is cut and free.This may seem trivial -- showing you how totear the paper. But too many times a studenthas tried to yank the paper out instead ofstarting a tear and tearing it neatly. Yankingthe paper can result in the paper being tornbelow the plastic cutting surface on therecorder, and the paper gets jammed downinside the recorder.If this happens, the entirerecorder has to be dis-assembled,a process which takes about 15minutes, thus putting the entireGC out of service until it can befixed.Gas ChromatographyStudy Questions/Answers from the Handbook for Organic Chemistry LabIn gas chromatography (GC), the stationary phase is a high-boiling liquid and the mobile phase is an inert gas. In the organic chemistry teaching labs at CU Boulder, GC is used as an analytical tool to find out how many components are in a mixture. It can also be used to separate small amountsof material.Movie on how to run a GC. To view this movie, you need the RealOne movie player. If you do not have this installed in your browser, go to and click on the box in the upper right hand corner that says "free download". Streaming video works best if you are on the University campus; if you are using a dialup modem, the quality is acceptable but not great.The GC InstrumentThe process of gas chromatography is carried out in a specially designed instrument. A very small amount of liquid mixture is injected into the instrument and is volatilized in a hot injection chamber. Then, it is swept by a stream of inert carrier gas through a heated column which contains the stationary, high-boiling liquid. As the mixture travels through this column, its components go back and forth at different rates between the gas phase and dissolution in the high-boiling liquid, and thus separate into pure components. Just before each compound exits the instrument, it passes through a detector. When the detector “sees” a compound, it sends an electronic message to the recorder, which responds by printing a peak on a piece of paper.The two brands of GCs used in the organic chemistry teaching labs are shown below: Gow-Mac series 350 on the left, Varian Aerograph Model 920 on the right. Click on each photo for a detailed enlargement.The GC consists of an injection block, a column, and a detector. An inert gas flows through the system. The injection chamber is a heated cavitywhich serves to volatilize the compounds. The sample is injected bysyringe into this chamber through a port which is covered by a rubberseptum. Once inside, the sample becomes vaporized and is carried out ofthe chamber and onto the column by the carrier gas.The large photo below is of the inside of a GC, showing the column in theoven and the insulated chamber tht houses the detector. Click on thethumbnails to see larger photos of the column and detector, as well asthe inside of the injector port (showing the septum).inside ofthe injector port the septumthe columnthe detector inside the housing On the Varian 920 andGow Mac 350chromatographs, detectionof the compounds is achieved with a thermalconductivity (TC or hotwire) detector.The column (see the photo above) is an integral part of the GC system.On the outside, all you see is a long stainless steel tube, 1/8 to 1/4inch in diameter and 4-5 feet long, which is coiled to fit inside theinstrument. Inside the column is the important component: the stationaryphase composed of the high-boiling liquid. The liquid is usuallyimpregnated on a high surface area solid support like diatomaceous earth,crushed firebrick, or alumina. The liquid can be applied in variousconcentrations: the more liquid, the more sites it has to interact withthe compounds.All of our GCs have columns which are five feet long and 1/8" or 1/4" indiameter and contain a methyl silicone polymer liquid phase (OV-101, 1.5%)on a diatomaceous earth support (chromosorb G). Methyl silicone is aliquid phase of intermediate polarity, and non-polar compounds such willseparate according to their respective boiling points.The carrier gas is an inert gas, helium. The flow rate of the gas influenceshow fast a compound will travel through the column; the faster the flowrate,the lower the retention time. Generally, the flow rate is held constantthroughout a run. (The GCs at CU Boulder are set at a flow rate of 55mL/min.)This is where the carrier gas enters the Variathe gas flow rate can be adjusted. Click onfor details.In a professional laboratory, the GC conditions would be critical foranother experimenter trying to duplicate your observations. All of ourGCs have the same columns (1.5% OV-101 on Chromasorb G) and the same flowrate (55 mL/minute) and detector bridge current (150 mAmps). Eachinstrument will have a different setting for:∙column temperature∙injection port temperature∙detector temperatureIt is a good practice to write down some of the settings on the instrument.The values for these temperaturs are viewed by turning the knob on theinstrument below the gauge -- click on the thumbnails below to see detailedphotos of how to do this.reading temperatures on theGow-Macreading temperatures on the VarianRecordersTwo devices are used to record the GC traces/areas under peaks:∙integrating recorders∙computer programEach type of device records the messages sent to them by the detector as peaks, calculates the retention time, and calculates the area under each peak; all of this information is included in the printout. For similar compounds, the area under a GC peak is roughly proportional to the amount of compound injected. If a two-component mixture gives relative areas of 75:25, you may conclude that the mixture contains approximately 75% of one component and 25% of the other.An integrating recorder is pictured below. Click on the photo for a detailed picture and the location of the start button (press when you inject), the stop button (press when you have seen your peaks, it tells the recorder to do the calculations and to print), and the enter button (paper feed).The screen of one of the computers is pictured below. Click on this image to link to screen shots of how to start, stop, calculate, and print a GC trace using the computer program.Retention Time (RT)The retention time, RT, is the time it takes for a compound to travel from the injection port to the detector; it is reported in minutes on our GCs. The retention time is measured by the recorder as the time between the moment you press start and the time the detector sees a peak. If you do not press start at the same time you inject your sample, the RT values will not be consistent from run to run.Factors which affect GC separationsEfficient separation of compounds in GC is dependent on the compounds traveling through the column at different rates. The rate at which a compound travels through a particular GC system depends on the factors listed below:∙Volatility of compound: Low boiling (volatile) components will travel faster through the column than will high boiling components∙Polarity of compounds: Polar compounds will move more slowly, especially if the column is polar.∙Column temperature: Raising the column temperature speeds up all the compounds in a mixture.∙C olumn packing polarity: Usually, all compounds will move slower on polar columns, but polar compounds will show a larger effect.∙Flow rate of the gas through the column: Speeding up the carrier gas flow increases the speed with which all compounds move through the column.∙Length of the column: The longer the column, the longer it will take all compounds to elute. Longer columns are employed to obtain better separation.Generally the number one factor to consider in separation of compoundson the GCs in the teaching labs is the boiling points of the differentcomponents. Differences in polarity of the compounds is only importantif you are separating a mixture of compounds which have widely differentpolarities. Column temperature, the polarity of the column, flow rate,and length of a column are constant in GC runs in the Organic ChemistryTeaching Labs. For each planned GC experiment, these factors have beenoptimized to separate your compounds and the instrument set up by thestaff.Procedure for GCGas ChromatographyGas Chromatography (GC) is used to separate volatile components of a mixture. A small amount of the sample to be analyzed is drawn up into a syringe. The syringe needle is placed into a hot injector port of the gas chromatograph, and the sample is injected. The injector is set to a temperature higher than the components’ boiling points. So, components of the mixture evaporate into the gas phase inside the injector. A carrier gas, such as helium, flows through the injector and pushes the gaseous components of the sample onto the GC column. It is within the column that separation of the components takes place. Molecules partition between the carrier gas (the mobile phase) and the high boiling liquid (the stationary phase) within the GC column.Top View of Oven and ColumnsTwo columns will fit insidethe oven of our GCs. Aheating element is used toraise the oven temperature,when desired, and thus raisethe column temperature. GCcolumns typically have ametal identification tagclipped onto the column thatlists column length anddiameter, what material isinside, and the maximumoperating temperature.After components of the mixture move through the GC column, they reach a detector. Ideally, components of the mixture will reach the detector at varying times due to differences in the partitioning between mobile and stationary phases. The detector sends a signal to the chart recorder which results in a peak on the chart paper. The area of the peak is proportional to the number of molecules generating the signal.To use the GC, follow these simple steps:1.Wash a syringe with acetone by filling the syringe completely and ejecting the waste acetone onto a paper towel. Wash 2-3 times.2.Pull some of your sample into the syringe. You will most likely need to remove air bubbles in the syringe by rapidly moving the plunger up and down while the needle is in the sample. Usually 1-2 L of sample is injected into the GC. It is okay to have small air bubbles in the syringe. However, you do not want to inject mostly air or your peaks will be too small on the chart recorder.3.Make sure the chart recorder is on and set to the appropriate chart speed (Arrow A). Set the baseline using the zero on the chart recorder (Arrow B). With the pen in place, turn on the chart (Arrow D), make sure the pen is down (marking the paper) and the paper is moving.ArrowA Set chart speed in cm/minArrow B Set zero so that the baseline is ~ 1 cm from bottom (right edge) of chart paperArrow C Record (but do not adjust) full scale settingArrow D Switch to turn movement of chart paper on and off.4.Inject your sample onto either column A or column B as instructed. Hold the syringe level and push the needle completely into the injector. Once you can no longer see the needle, quickly push the plunger and then pull the syringe out of the injection port.Injection Notes:A) The injectors are very hot, so be careful not to touch the silver disk.B)The needle will pass through a rubber septum, so you should feel some resistance. For some of our GC’s, the column does notalign properly in the injector, so the needle hits the front of the metal column. If you feel that you are pushing against metal, pull the needle out of the injector and try again, perhaps at a slightly different angle. The needle should completely disappear into the injector for proper injection of the sample onto the GC column.C)Inject quickly for best results. Do not hesitate to inject once the needle is properly positioned in the injection port.D)Remove the syringe immediately after injection. (Carrying out notes C and D helps to insure that all of the sample enters theGC column at approximately the same time.)5.Mark your injection time on the chart recorder. This can be done by adjusting the zero just after the sample is injected. It is often convenient for one person to inject the sample while a lab partner marks the injection time at the chart recorder.6.Clean your syringe immediately after injection. Syringe needles often clog quickly and must be replaced if they are not cleaned after each use.7.Record the settings of your chart recorder during a run. You need to know the chart speed and the full-scale setting.8.Record the settings of your GC during a run. A knob on the bottom center of the GC can be turned to read column (or oven) temperature, detector temperature, and injector port temperature in °C. The bridge current is displayed in mA. Note that there are two scales on the display. Be careful to read the appropriate scale!ArrowA Top scale is reported in milliamps and is used to read the bridge current.Arrow B Bottom scale is reported in degrees Celsius and is used to read all temperatures.Arrow C Typically the ONL Y knob to be adjusted by students. Knob is turned for corresponding reading on the scale above the knob.Arrow D Increasing the Attenuator setting decreases the area of a peak on the chart recorder. This knob should only be adjusted with permission of instructor. Always return the knob to its original setting if you are given permission to change it.Analysis of the Gas ChromatographReport the retention time of each peak (in minutes), the identity of each component in the mixture, and the percent composition of the mixture. To determine the percent composition, you will first need to find the area under each curve.Area = (height) x (width at ½ height)Mark retention time, height, half-height, and width at ½ height on your GC trace. Show your calculations either in your final report or directly on the chromatograph.You may assume that each component of the mixture causes the same response in thedetector. Therefore, the areas under the curves can be used to calculate percent composition of the mixture of alkenes. (This is a reasonable assumption when the components of the mixture are very similar in structure, as are 2-methyl-1-butene and 2-methyl-2-butene.)% Component 1 = [(area under peak 1)/(total area)] x 100%The sample used to obtain the GC trace that is shown above did not have any solvent in it. Student samples will have at least one solvent present, so you will see another peak in your GC traces that typically appears very soon (usually within a minute) after injection. It is normal for the solvent peak to go off scale.。
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PEG-20M
OV-1701 OV-17 OV-101 SE-52 SE-30
Influence of column parameters
Internal diameter:
The selection of internal diameter of the column is based on the sample concentration.
tube wall stationary liquid To detector
Time 1
Time 2
Time 3
Column Polarity Scale
Non-Polar columns for non-polar compounds (alkanes) that contain (1) only carbon and hydrogen atoms, and (2) only single bonds between carbon atoms. Intermediate polar columns for an alternate selectivity of non-polar and/or polar compouds. Polar columns for polar compounds that contain (1) primarily carbon and hydrogen atoms, and (2) also some bromine, chlorine, fluorine, nitrogen, oxygen, phosphorus, and/or sulfur atoms. Highly polar columns for polarizable compounds that contain (1)only carbon and hydrogen atoms, and (2)some double and /or triple bones between carbon atoms. Extremely polar columns for additional selectivity of polarizable compounds.
Length: Longer columns provide greater resolution of
sample components. However, increasing column length increases analysis time. Standard length: 25~30m. Short column: 5~15m. Long column: more than 50m.
Concentration
2 pg
107
Analysis of the gas chromatograph
Qualitative analysis: substances are identified by the order in which they emerge from the column and by the retention time of the analyte in the column.
30 m
60 m
Detector
The most commonly used detectors are the flame ionization detector (FID) and the thermal conductivity detector (TCD). Other detectors are sensitive only to specific types of substances, or work well only in narrower ranges of concentrations.
Classification
Capillary Column
a polyimide coating. 10-100m in length. 0.1-0.5mm in internal diameter.
stationary phase
The selection of stationary phase is based on the “Similar Compatible Principle”. outer layer
canister purge line
Sample injection port
Columns
Packed Column
a finely divided, inert, solid support material with liquid stationary phase. 1.5-10m in length. 2-4mm in internal diameter.
Internal standard method
Thank You！
Gas Chromatography
Introduction
Gas chromatography involves:
A sample being vapourised Transport through the column
Injected onto the separation column Detector Recorder
Film Thickness:
Thin film(0.1~0.2μm): used for high boiler, such as petroleum chemicals, triglyceride. Standard film(0.25~0.5μm): mostly wide used. Thick film(1~5μm): used for chemicals with low boiling point.
Detector Flame ionization (FID) Thermal conductivity (TCD) Electron capture (ECD)
Type Mass flow Concentration
Selectivity Most organic compounds. Universal Halides, nitrates, nitriles, peroxides, anhydrides, organometallics Nitrogen, phosphorus , phosphorus, tin, boron, arsenic, germanium, selenium, chromium Aliphatics, aromatics, ketones, esters, aldehydes, amines, heterocyclics, organosulphurs, some organometallics
Area normalization method Quantitative analysis
External standard method
Internal standard method
ቤተ መጻሕፍቲ ባይዱ
Area normalization method
External standard method
Instrumental components
Carrier gas The carrier gas must be chemically inert. Commonly used gases include nitrogen, helium, argon, and carbon dioxide. The choice of carrier gas is often dependant upon the type of detector which is used. The carrier gas system also contains a molecular sieve to remove water and other impurities.
Detectability Dynamic range 100 pg 1 ng 107 107
Concentration
50 fg
105
Nitrogen-phosphorus
Mass flow
10 pg
106
Flame photometric (FPD)
Mass flow
100 pg
103
Photo-ionization (PID)