用大口径毛细管气相色谱法快速测定塑料食品包装袋中有机残留物

采用５３０μｍ大口径毛细管色谱柱,顶空气相色谱－火焰电离检测器测定,建立了一种塑料食品包装袋中有机溶剂———甲苯、乙酸乙酯、丁酮和异丙醇残留的气相色谱快速分析方法,回收率为９４．８％～１０１．６％,相对标准偏差为０．８％～２．７％。方法简便、灵敏、准确、重现性好。     

Pulsed discharge photoionization detector: Application to analysis of chloro alkanes/alkenes

A windowless pulsed discharge photoionization detector (PDPID) is described which uses the emission spectra from the discharge in helium and Ar/Kr doped helium. The emission from helium is a continuum ranging from 13.5–17.7 eV which ionizes all compounds except neon. The emission from 5.4% Ar/He ranges from 9.3–11.8 eV and ionizes most organic compounds and many inorganic compounds. The emission from 1.36% Kr/He consists principally of the resonance lines at 10.6 and 10.1 eV. These PDPIDs are used to analyze a 12 component mixture containing principally chloro alkane/alkene. The relative responses of the PDPID combined with the relative retention time can be used to qualitatively identify the chloro compounds.     

Simultaneous Measurement of Hydrocarbons and Sulfur Compounds using Flame Ionization and Sulfur Chemiluminescence Detection for Sulfur Simulated Distillation

A gas chromatographic system for the simultaneous acquisition of hydrocarbon and sulfur chromatograms was developed. Detection of sulfur compounds is achieved using a sulfur chemiluminescence detector (SCD) mounted in series with a flame ionization detector (FID). A constant fraction of the effluent of the FID is transferred to the SCD by means of a fixed restrictor. Unlike previous versions of this approach, the FID is not used to generate the chemiluminescent sulfur species. Rather, the FID is operated under optimum conditions for hydrocarbon analysis and a furnace is used to generate the chemiluminescent sulfur species. The system permits dual acquisition of the hydrocarbon and sulfur signals in a single analysis with a single column, since the detectors are operated in a serial fashion. The application of sulfur simulated distillation using this approach was examined, since this requires simultaneous universal and sulfur selective detection. Precision of absolute response of both the FID and SCD was typically less than 2% RSD for a standard reference material.     

顶空毛细管气相色谱法测定吡虫啉中的丁酮

采用顶空毛细管气相色谱法测定吡虫啉中的丁酮残留量。样品经二氯甲烷溶解,用HP–5毛细管色谱柱分离,氢火焰离子化检测器检测,顶空平衡温度为70℃,平衡时间为10 min,以外标法计算含量。丁酮的质量浓度在2.0~510.0μg/m L范围内线性关系良好,相关系数r=0.999 7,方法的检出限为0.5μg/m L,样品3个水平的加标回收率为99.4%~102.1%,测定结果的相对标准偏差小于3.0%(n=5)。该方法简便快速,准确可靠,可用于吡虫啉产品的质量控制。     

Carbon response characteristics of a micro-flame ionization detector

The carbon response characteristics of a recently noted micro-flame ionization detector (μFID) mode are examined in detail. The μFID supports an extremely small (30 nL) “upside-down” flame that is generated from a low counter-current flow of oxygen immersed in hydrogen. Ionization measurements made in the μFID are directly compared to those obtained from a conventional FID. In terms of reproducibility of response and relative sensitivity towards different types of hydrocarbons, the μFID and a conventional FID produce no major differences with respect to either of these characteristics for a variety of compounds examined. Of note, for replicate measurements made in each detector, the average %R.S.D. of response typically differs by less than 2% between the two devices, while the average normalized sensitivity differs by less than 4%. In contrast to this, regarding absolute sensitivity, the analyte signal from the conventional air-rich FID is found to be three times larger than that of the hydrogen-rich μFID mode explored here. This discrepancy is ascribed directly to the difference in flame stoichiometry between the two detectors.     

Micro-machined planar field asymmetric ion mobility spectrometer as a gas chromatographic detector

A planar high field asymmetric waveform ion mobility spectrometer (PFAIMS) with a micro-machined drift tube was characterized as a detector for capillary gas chromatography. The performance of the PFAIMS was compared directly to that of a flame ionization detector (FID) for the separation of a ketone mixture from butanone to decanone. Effluent from the column was continuously sampled by the detector and mobility scans could be obtained throughout the chromatographic analysis providing chemical inforrmation in mobility scans orthogonal to retention time. Limits of detection were approximately I ng for measurement of positive ions and were comparable or slightly better than those for the FID. Direct comparison of calibration curves for the FAIMS and the FID was possible over four orders of magnitude with a semi-log plot. The concentration dependence of the PFAIMS mobility scans showed the dependence between ion intensity and ion clustering, evident in other mobility spectrometers and atmospheric pressure ionization technologies. Ions were identified using mass spectrometry as the protonated monomer and the proton bound dimer of the ketones. Residence time for column effluent in the PFAIMS was calculated as approximately 1 ms and a 36% increase in extra-column broadening versus the FID occurred with the PFAIMS.     

Comparative Response Characterization of a Universal Acoustic Flame Detector for Chromatography

The relative response towards a wide variety of hydrocarbons was measured simultaneously in both the acoustic flame detector (AFD) and the flame ionization detector (FID). The compounds examined included alkanes, aromatics, unsaturates, aldehydes, ketones, alcohols, carboxylic acids, and a number of hetero-atomic organic analytes. A very close linear correlation was found between AFD and FID response for these analytes with regression providing an r ² coefficient of 0.9103. The observed universal AFD response towards hydrocarbons was attributed to a reduction in flame burning velocity through the capture of key propagating species such as hydrogen radicals. While a few minor exceptions to this correlation were observed, the most notable differences occurred for organometallic compounds, which responded 2–3 orders of magnitude more strongly in the AFD than anticipated by their FID response alone. It was found that the metals present in such analytes are directly responsible for generating the greatly increased AFD response observed, which is attributed to their known radical scavenger properties. Results indicate that overall the AFD provides a uniform response towards most hydrocarbons that is qualitatively very similar to that of an FID. For those analytes containing metals or other moieties that may be capable of significantly altering flame burning velocity, an enhanced AFD response is to be anticipated.     

烟用香精的气相色谱法质量控制研究

采用配有氢焰检测器或催燃检测器的气相色谱仪,对烟用香精进行了快速分析。方法操作简便,结果可靠,可作为烟用香精原料、产品质量监控的有效手段。     

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.     

Universal and discriminative detection using a miniaturized pulsed discharge detector in comprehensive two-dimensional GC

A miniaturized pulsed discharge detector (Mini-PDD) has been successfully demonstrated for comprehensive 2-D GC (GC x GC) analysis of pyrolysis gasoline and the pyrolysis GC x GC analysis of a polyethylene copolymer. The detector cell volume of the Mini-PDD is reduced to 25% of the Valco plug-in PDD D-3. An n-C11 peak width at base is 96 ms for the Mini-PDD, about 23% larger than a peak width of 78 ms detected by a flame ionization detector (FID). The Mini-PDD has sufficient response time for most GC x GC applications. When Mini-PDD is operated in helium photoionization mode (Mini He-PDD), it is a universal detector for both inorganic and organic compounds. This is especially useful when detection of water is needed in GC x GC applications. When krypton is doped in the helium discharge gas (Mini Kr-PDD), it can suppress signals of compounds having higher ionization potentials and enhance relative signal intensities of aromatic compounds. The determination of aliphatic to aromatic hydrocarbon ratios is essential to the operation of petroleum crackers. Comparison of the signal from two modes of the Mini-PDD is a simple and fast way to verify the location of aromatics in comprehensive 2-D gas chromatograms.     

顶空-气相色谱法测定葡萄糖氯化钠注射液中12种溶剂残留量

建立顶空-气相色谱法测定葡萄糖氯化钠注射液中12种残留溶剂含量的方法。采用HP-INNOWAX毛细管色谱柱(60 m×320μm,0.5μm)为分离柱,检测器为氢火焰离子化检测器(FID),柱温为程序升温。12种残留溶剂乙醇、异丙醇、丙酮、丁酮、乙酸乙酯、乙酸丁酯、乙酸正丙酯、甲苯、乙苯、对二甲苯、邻二甲苯、间二甲苯均能完全分离,在考察的浓度范围内线性关系良好(r>0.995),检出限分别为0.055,0.019,0.023,0.070,0.155,0.013,0.003,0.009,0.004,0.004,0.004,0.005μg/mL。平均回收率为90.6%~109.0%,测定结果的相对标准偏差为2.2%~5.6%(n=9)。该方法专属性强,精密度、准确度和检测灵敏度高,重复性好,可用于葡萄糖氯化钠注射液中12种溶剂残留量的测定。     

摩尔响应值与拓扑指数的关系

考察了链烷烃、链烷醇、酮和苯系列化合物的摩尔响应值与拓扑指数的关系,结果表明两者之间存在良好的线性关系。     

Determination of percent composition of a mixture analyzed by gas chromatography. Comparison of a helium pulsed-discharge photoionization detector with a flame ionization detector

We present the results of a study of percent composition for a mixture which has been separated by gas chromatography and analyzed using helium pulsed-discharge photoionization detection (He-PDPID) and flame ionization detection (FID). FID has long been the means by which the percent composition of a hydrocarbon mixture has been determined since it has been previously established as a "carbon counting device". However, in this study we present results which show that He-PDPID is more accurate in determining the percent composition of a hydrocarbon mixture and, because it is a universal detection method and can detect compounds that FID cannot, it is also more effective for determining the percent composition of mixtures containing organic compounds with a variety of other functional groups.     

Simplification of determination method for standard materials using post-column reaction GC/FID

For the simple and fast preparation of highly reliable standard materials, a post-column reaction GC/FID system was developed and evaluated on the mixture of oxygen-containing organic compounds. The oxygen-containing organic compounds mixing solution were determined with the post-column reaction GC/FID system using n-dodecane as an internal calibration standard. Required value of relative expanded uncertainty as an original source of SI-traceable standard materials was within 1% and it aimed at this value as accuracy of the quantitative analysis. The results showed good agreement between the prepared concentrations and analytical values using post-column reaction GC/FID system. These results indicated that the post-column reaction GC/FID system would be used for getting SI-traceable values.     

Analytical bias among different gas chromatographic approaches using standard BTX gases and exhaust samples

In this study, the analytical compatibility of the gas chromatographic (GC) approach was evaluated through a cross‐calibration exercise. To this end, three aromatic volatile organic compounds (VOCs: benzene, toluene, and p‐xylene (BTX)) were simultaneously analyzed with four individual instrumental setups (type I = GC with MS plus solid phase microextraction (SPME) method, II = GC with flame ionization detection (FID) plus SPME, III = fast GC‐FID plus SPME, and IV = GC‐FID plus air server/thermal desorption (AS/TD) method). A comparison of basic quality assurance (QA) data revealed considerable differences in DL values among the methods with moderate variabilities in the intercompound sensitivity. In light of the differences in detection properties, the analytical bias involved for each methodological approach was assessed by the relative relationship between analytes and basic operating conditions. The results suggest that the analysis of environmental samples at ultra‐low concentration levels (at or below ppb level) can be subject to diverse sources of bias. Although detection properties of target compounds seem to be affected by the combined effects of various factors, changes in the sample concentration levels were seen to be the most consistent under the experimental setups analyzed in this study.     

棒状薄层色谱/氢火焰法分析磺化酞菁钴的组成

研究建立了一种采用棒状薄层色谱／氢火焰离子检测（TLC／FID）对磺化酞菁钴组成进行定性、定量分析的方法。用薄层色谱并结合质谱分析 表明工业磺化酞菁钴中含有一磺化酞菁钴的两种同分异构体,二磺化酞菁钴的5种同分异构体及三磺化酞菁钴;用棒状薄层色谱／氢离子火焰检测方法可以对磺化酞菁钴中各组分进行定量分析。该方法操作简便,测定时间短,灵敏度高,可用于磺化酞菁钴工业合成的产品质量控制。     

Analysis of polynuclear aromatic hydrocarbons by glass capillary gas chromatography using simultaneous flame ionization and electron capture detection

The possibility of simultaneous application of an electron capture (ECD) and a flame ionization detector (FID) connected to a glass capillary column for analyzing polynuclear aromatic hydrocarbons (PNA) has been investigated. The ECD/FID ratio is determined for 46 PNA compounds. The ratios vary from 0.02 to 117 with relative standard deviations better than 20 percent determined from 10 replicate analyses. The results suggest that the method may be used for obtaining additional evidence in identifying PNA in environmental samples. Impurities and transformation products in the standard were identified by computerized glass capillary gas chromatography/mass spectrometry. Quinones and diones are responsible for the high EC-response determined in some trace components in the standard. An application of the method is shown for PNA from particulates in urban atmospheres.     

Investigating the performance characteristics of the barrier discharge ionization detector and comparison to the flame ionization detector for the gas chromatographic analysis of volatile and semivolatile organic compounds

Abstract

The response behavior and performance characteristics of the recently introduced barrier discharge ionization detector (BID) for gas chromatography (GC-BID) were investigated by analyzing different classes of organic compounds such as alcohols, alkanes, cycloaliphatic compounds, polycyclic aromatic hydrocarbons (PAHs), and others. The results obtained by GC-BID were compared with those of gas chromatography with flame ionization detection (GC-FID), aiming to demonstrate the particular merits of the new BID detector over the well-established FID. The response of the BID not only was found to be strongly dependent on the detector settings, but also shows a high dependence on the analyte class and the individual analyte. The sensitivity of the BID detector compared to the FID was higher by a factor of ca. 4 on average when considering all compounds analyzed. The relative standard deviation (RSD) was better than 5% for the majority of the cases. The BID detector showed better precision (lower RSD) in comparison with the FID for the investigated compounds. Linear calibrations were obtained for the analytes over more than four orders of magnitude with coefficients of determination typically higher than 0.999 and the limits of detection varied from 0.04 to 1.48?ng/s for the GC-BID.     

Organic fuelled flames in selective ionization detectors for chromatography

Summary The selectivities of two flame-based ionization detectors identified as a Remote FID (RFID) and a Flame Thermionic Ionization Detector (FTID) have been improved by introducing methane as a fuel for the flame. Both the RFID and FTID feature a detector struture in which the ionization polarizer and collector are located several centimeters downstream of an oxygen-rich flame, rather than immediately adjacent to the flame as in a flame ionization detector. The RFID detects long-lived negative ions produced in the flame by the combustion of lead, tin, phosphorus, or silicon compounds. The FTID re-ionizes and detects neutral electronegative products generated by combustion of nitrogen, halogen, or phosphorus compounds. An organic-fuelled RFID can detect 1 pg Pb (Sn, P)/sec with a selectivity of the order of 10⁶ versus hydrocarbons. An organic fuelled FTID is applicable to detection of compounds at nanogram and higher levels. FTID selectivity for PCB compounds in a transformer oil matrix is of the order of 10⁵1. The improved selectivity achieved by using an organic-fuelled flame is also applicable to the detection of phospholipid and other non-volatile N, P, or Cl compounds using an FID/FTID detector accessory for a TLC/FID analyser.