气相色谱仪FID检定过程中的常见故障及排除

气相色谱仪氢火焰离子化检测器（FID）检定过程中常见故障为仪器无法正常点火、仪器进样重复性差、仪器基线噪声漂移大，对这些故障原因进行了分析并提出了解决办法。     

无自身标准样品GC-FID法测定标准物质中有机杂质含量

建立了一种标准物质中有机杂质的无自身标准样品准确定值的GC–FID方法。以与待测有机杂质结构相似的物质作为参考物质校准GC–FID响应信号,采用有效碳数法计算待测杂质的质量响应值Si,检测出样品中该有机杂质的准确含量。以癸二酸二正丁酯纯度标准物质为例,用该法对其中有机杂质总量进行定值,定值结果为0.29%,U=0.07%(k=2)。定值不确定度主要来源于Si和检测重复性。     

气相色谱仪检定结果的不确定度评定

气相色谱仪检定结果的不确定度主要来源于流速稳定性、柱箱温度稳定性、基线噪声、定量重复性和标准物质进样量的不确定度。以TCD检测器为例进行分析,对气相色谱仪检定结果的不确定度进行评定,相对扩展不确定度为5%。     

浅析气相色谱仪计量标准的重复性试验

根据气相色谱仪计量标准的特点,基于重复性的定义和解释,以在线气相色谱仪为例分析重复性试验方法,探讨新建和已建气相色谱仪计量标准的重复性试验应满足的要求。新建气相色谱仪计量标准重复性试验结果首先应满足JJG 700–1999《气相色谱仪》或JJG 1055–2009《在线气相色谱仪》检定规程的要求;其次应满足量值溯源要求的检测器灵敏度或检测限不确定度的要求;已建气相色谱仪计量标准重复性试验结果应不大于新建计量标准时的重复性。     

气相色谱法测定车用汽油中甲醇和苯

采用1,2,3-三-(2-氰基乙氧基)丙烷(简称TCEP)微填充柱(56 cm×1.6 mm)和HP-1石英毛细管柱(30 reX0.53 mm,0.5 μm)及带有十通阀系统的气相色谱仪,自动进样器进样,外标法定量.样品在TCEP微填充柱中得到初步分离后,并用火焰离子化检测(FID B)检测,放空先于甲醇和苯流出的组分,然后切换十通阀,将还未从TCEP微填充柱中流出的组分反吹到HP-1毛细管柱中分离并用FID A检测.汽油样品无需预处理直接一次进样同时测定车用汽油中甲醇和苯含量.甲醇及苯的峰面积与相应的浓度之间在50.0 g·L-1及100.0 g·L-1以内呈线性关系,甲醇的检出限为0.5 g·L-1,回收率为93.3%;苯的检出限为0.02 g·L-1,回收率为97.0%.     

生物质合成气一步法合成二甲醚的在线分析系统

建立了一套由生物质合成气一步法制取二甲醚的在线分析系统.针对生物质合成气一步法合成二甲醚特征,采用两台分别装有TCD和FID检测器的色谱仪分析反应产物.利用原料气中N2作为内标物,来确定TCD上检测到的永久性气体组分浓度;通过CH4作内标物,来确定FID上检测到的有机物组分浓度.TCD和FID之间通过CH4来关联,从而确定反应产物中主要组分的浓度.该系统在压力3 MPa,温度250℃,空速(流速与催化剂体积的比值)分别为1 000、2 000、3 000 h-1的条件下用C306和HZSM-5催化剂进行评价测试,发现系统分析效果好,重复性高,并且反应前后主产物碳平衡到达90%以上.     

卷烟主流烟气气相物和总粒相物中有机酸的分析研究

以二氯甲烷-甲醇为萃取溶剂,N,O-双(三甲基硅基)三氟乙酰胺(BSTFA)为硅烷化试剂,采用配备氢火焰离子化检测器(FID)的气相色谱仪分别对卷烟主流烟气中气相物和总粒相物中甲酸、乙酸、硬脂酸等21种有机酸进行了定量分析。对样品主流烟气中气相物前处理硅烷化条件及有机酸萃取条件进行了优化,并采用气相色谱法对卷烟主流烟气中气相物和总粒相物中有机酸的含量进行了定量分析。该方法用于实际样品中挥发性有机酸分析时,回收率为88.12%～98.63%,相对标准偏差(RSD)为1.51%～8.38%。     

短柱毛细管气相色谱法快速测定蛋黄中的总胆固醇

文献所载食品中胆固醇的测定方法繁杂费时,本文用毛细管短柱试验了胆固醇的分离检测方法,探讨了样品处理的合适条件。 实验部分 (一)仪器和试剂 SP3400气相色谱仪,FID检测器,1075型进样器,SP4290M积分仪。胆固醇标样系荷兰进口分装,其它试剂为分析纯。取60％的KOH水溶液加适量     

气相色谱仪FID检出限的测量不确定度

通过分析测量气相色谱仪FID检出限过程中各分量引入的测量不确定度,对FID栓出限的测量不确定度进行了评定。FID栓出限的相对不确定度为1.7％,扩展不确定度为3.4％（k=2）,采用比对法验证了评定结果的合理性。     

放电离子化气相色谱仪在高纯度氢分析中的应用

论述放电离子化（DID）检测器气相色谱仪的工作原理．通过高纯氢中杂质分析,从检测限、重复性、再现性以及线性范围4个方面阐述了放电离子化气相色谱仪在高纯度氢检测分析中的应用．     

乙酰甲胺磷丙酮溶液标准物质的制备及定值

采用乙酰甲胺磷纯度标准物质为原料,以丙酮为溶剂,制备了浓度为1．00mg／mL的乙酰甲胺磷丙酮溶液标准物质,用液相色谱法和气相色谱法进行了确认,A类标准不确定度为0．009％,B类标准不确定度包括标准物质制备、原料纯度、不均匀性和不稳定性引入的不确定度,其量值分别为0．43％,0．10％,0．87％和0．24％,合成不确定度为0．03mg／mL（k=-2）,乙酰甲胺磷丙酮溶液标准物质的浓度为（1．00±0．03）mg／mL。     

Continuous solid-phase extraction and gas chromatographic determination of organophosphorus pesticides in natural and drinking waters

A simple, rapid continuous-flow solid-phase extraction method with gas chromatographic detection for the determination of organophosphorus pesticides is proposed. The continuous system consists of an adsorbent column where pesticides are preconcentrated and subsequently eluted with ethyl acetate. Various sorbent materials were assayed of which RP-C18 was found to provide the best results, with a sorption efficiency close to 100%. A comparative study of the determination of pesticides in aqueous samples was conducted using gas chromatography with nitrogen-phosphorus (NPD) and flame ionization (FID) detection. The detection limits of the method for 10 ml of sample were between 50-130 ng/l and 4.5-1 1.7 microg/l with NPD and FID detection, respectively. The method was used to determine organophosphorus pesticides in river, pond, well and tap waters, all with good precision (2.9-4.3%) and recoveries ranging from 93.8 to 104.5%.     

衍生化气相色谱法测定早强剂中三乙醇胺含量

建立了衍生化气相色谱法定量分析水泥早强剂中三乙醇胺含量的方法。以丙三醇作为内标,采用HP-5毛细管柱分离样品,氢火焰离子化检测器(FID)测定三乙醇胺含量。三乙醇胺在0.2～5.0mg/mL范围内与三乙醇胺/内标的乙酰化物色谱峰面积的比值呈线性关系,相关系数r=0.9996。方法检出限为42.6μg/mL,平均回收率为96.6%,相对标准偏差(RSD)为0.759%。该方法具有操作简便、快速、准确等优点,可用于测定水泥早强剂中三乙醇胺的含量。     

毛细管气相色谱法测定丙烯中烃类杂质的含量

以PLOT／Al2O3石英毛细管柱为分析柱，采用氢火焰离子化检测器，建立了测定丙烯中烃类杂质含量的毛细管气相色谱法。丙烯中烃类杂质含量测定结果的相对标准偏差小于5％，分析时间约30min，测定值与国家标准方法基本一致。该方法操作简便，分析速度快，准确度高，重复性好。     

水中痕量苯酚的微波萃取气相色谱分析

A method of microwave-assisted extraction and gas chromatography for determination of trace phenol in water was established.The conditions of microwave extraction and derivation were optimized.Acetone-cyclohexane(1∶1) mixture was used as extracting agent for water sample containing phenol and acetic anhydride was employed for the direct acetylation of phenol.Petroleum ether was used as the extracting agent to extract the derivative of phenol.Detection was carried out in GC-FID equipped with DB-17(30 m×0.53 ...     

气相色谱法同时测定初烤烟叶中的4种水溶性糖

建立了一种用三甲基氯硅烷及六甲基二硅胺烷衍生化,气相色谱-氢火焰离子化检测器同时测定初烤烟叶中4种水溶性糖的检测方法。烟叶样品用50%(V/V)的乙腈溶液振荡提取,无需净化,直接用三甲基氯硅烷及六甲基二硅胺烷衍生化,产物通过微型液-液萃取净化后用气相色谱检测。通过优化前处理条件和讨论基质效应,果糖、葡萄糖、蔗糖和麦芽糖的含量均与其峰面积呈良好的线性关系(相关系数为0.9991～0.9999),添加回收率为98.14%～102.45%,重复性较好(RSD<2.2%),该方法适用于初烤烟叶中果糖、葡萄糖、蔗糖和麦芽糖的同时测定。     

Development and single-laboratory validation of a new gas chromatographic multi-pesticide method of analysis of commercial emulsifiable concentrate formulations containing alachlor, chlorpyrifos methyl, fenthion and trifluralin as active ingredients

A multi-pesticide (MP) method was developed and single-laboratory validated for the quality control of commercial pesticide products containing alachlor, chlorpyrifos methyl, fenthion and trifluralin as active ingredients (a.i.). A capillary gas chromatographic system with flame ionization detection (FID) and a programmable temperature vaporising split injector was used. The performance characteristics (specificity, linearity, precision and repeatability) of the method satisfied international acceptability criteria.     

Capillary gas chromatography of pesticide residues in foods: Application of a split/splitless inlet system

Residue mixtures of pesticides in foods which were difficult to separate by packed-column gas chromatography were determined by capillary gas chromatography and electron capture detection. Manual injections of sample and reference standard were made with a 10 μL syringe on a septum-enclosed, split/ splitless inlet system. Optimal peak height repeatability (± 3%( was achieved with three-μL injections which were made within time periods of four hours or less. The average linearity coefficient (slope( obtained for detector response as a function of solution concentration was 1.1.     

Modified semi-rotating cryogenic modulator for comprehensive two-dimensional gas chromatography

A previously constructed semi-rotating cryogenic modulator was modified for comprehensive two-dimensional gas chromatography (GC×GC). The retention time repeatability was improved by replacing the modulator control program unit with a new system. Peak widths obtained with the modified modulator were comparable with those obtained with the previous modulator and other modulator types. The modulator was easy to construct and it can be installed in any commercial GC system. The constructed GC×GC–FID system and data obtained by gas chromatography–mass spectrometry (GC–MS) were used for identification of unknowns in forest aerosol samples. Figure A semi-rotating cryogenic modulator in which modulation is based on two-step cryogenic trapping with continuously flowing carbon dioxide has been developed for comprehensive two-dimensional gas chromatography