Flame ionisation detector for

The catalytic experiments were performed at the stationnary state and at atmospheric pressure, in a gas flow microreactor. The gas composition (NO, CO, O2, C3H, CO2 and H2O diluted with He) is representative of the composition of exhaust gases. The analysis, performed by gas chromatography (TCD detector for CO2, N2O, O2, N2, CO and flame ionisation detector for C3H6) and by on line IR spectrometry (NO and NO2) has been previously described (1). A small amount of the sample (10 mg diluted with 40 mg of inactive a AI2O3 ) was used in order to prevent mass and heat transfer limitations, at least at low conversion. The hourly space velocity varied between 120 000 and 220 000 h T The reaction was studied at increasing and decreasing temperatures (2 K/min) between 423 and 773 K. The redox character of the feedstream is defined by the number "s" equal to 2[02]+[N0] / [C0]+9[C3H6]. ... 

Gaier, M., Lagashina, M. N., Okhotnikov, B. P., Fesenko, E. P. Use of flame ionisations detector for the analysis of low boiling gases. Gaz. Khromatogr., Akad. Nauk SSSR, Tr. Vtoroi Vses Konf., Moscow 1962. - Chem. Abstr. 62, 4585 (1965). 

SSa) Craven, D. A. Simplified version of the alkali flame ionisation detector for nitrogen mode operation. Anal. Chem. 42, 1679 (1970). 

Zimmermann S, Krippner P, Muller J (2002) Miniaturized flame ionisation detector for gas chromatography. Sensors and Actuators B Chemical 83(l-3) 285-289... 

This uses ultraviolet radiation to produce ionised species which can be collected and detected as a current. Lamps of various energies (8.3, 9.5, 10.2, 11.7 eV) can be used to change the selectivity of tiie detector. Sensitivity is of the same order as the flame ionisation detector for amenable compounds, although it can be as low as 2 pg for benzene, with a dynamic range of 7 orders of magnitude. 

The catalytic tests were performed under atmospheric pressure in a gas flow microreactor which has been previously described (9). The analysis was performed both by gas chromatography equipped both with a TCD detector for CO2, N2O, O2, N2 and CO and with a flame ionisation detector for hydrocarbons. Moreover, a on- line IR spectrometer was used for NO and NO2 analysis. Whatever the experiments, which were carried out at relatively low O2 pressure, no NO2 formation was observed. 

Catalytic measurements were made using 100 mg catalyst diluted with 400 mg of inactive aAl203 in a fixed-bed flow reactor. The typical gas nuxture consisted of 2000 vpm NO, 2000 vpm CsHg, 10 vol. % O2, balance He, without or with 10 vol. % water (total flow rate 10 1 h ). In the absence of water in the reactant nrixture, the temperature was increased from 300 to 773 K (or 873 K) (heating rate 2 K min ) and then decreased to 423 K. Water was then added at 423 K and the temperature increased and decreased again as above. The analysis was performed by gas chromatography with two columns (porapak and molecular sieve) and a TCD detector for CO2, N2O, O2, N2 and CO, and with a porapak column and a flame ionisation detector for hydrocarbons. Moreover, on-line IR and UV analyzers were used for NO, NO2, CO2, and N2O analysis. The NO conversion was calculated from the N2 production and the nitrogen balance was checked. 

A tubular stainless steel reactor (I.D. 104 mm) heated by an electrical oven at atmospheric pressure is used for the oxidation of toluene [Fig. 1]. The toluene is dosed with an HPLC pump (LKB2150) to an evaporator at 320 °C and then mixed to the O2 and N2 flows which are controlled with mass flow controllers (Bronkhorst High-Tech B. V ). Nitrogen is used as diluent. The catalyst fixed-bed preceded by quartz beads is maintained between quartz wool. The temperature of the fixed-bed is measured with a K-type thermocouple (Philips AG). The outlet gases are cooled in three consecutive condensers. The liquid products are collected and analysed by gas chromatography with a flame ionisation detector for quantification (Perkin-Elmer Autosystem gas chromatograph, capillary column Supelco SPB-1, 30 m x 0.53 mm I.D. X 0.50 jum film thickness) and with an electron ionisation detector for identification (Hewlett-Packard, G1800A, GCD System, capillary column HP-5, 30 m x 0.25 mm I.D. x 0.25 fm film thickness). The experiments are carried out at a conversion less than 5 per cent. 

Catalytic activity measurements were carried out with a fixed bed flow reactor. The reactor was a quartz tube. The flow rates were adjusted using Brooks mass flow controller units. The composition of the effluents was analyzed by gas chromatography using a dual CTRl column fi-om Alltech (porapak for CO2, N2O, molecular sieve for O2, N2, CO) with a thermal conductivity detector and a porapak Q column with a flame ionisation detector for hydrocarbons. The mixture was analyzed every 13 minutes. NO and NO2 amounts were measured continuously on-line by means of Rosemount Infi-ared Analyzers. Helium was used as carrier gas as well as diluent gas. 

For packed-column use, any modern gas chromatograph should be suitable, but it is essential that it have a flame ionisation detector for maximum... 

GC-MS has for some time been a favoured technique for the identification of diacyigiyceroi species, separated in the form of the acetate and TMS or BDMS ether derivatives. Myher [642] and Saito et al. [784] have reviewed the topic in some depth and have tabuiated much vaiuabie data. Normaiiy it is advisabie to use the response of the flame ionisation detector for quantification of the main molecular species, and to use GC-MS for identification and quantification of isomers within a single peak. 

Gas chromatography was applied, using selective detectors electron-capture detector for organochlorine compounds, and alkali flame-ionisation detector for organophosphorus compounds. We determined ... 

Conversion to acetates, trifluoroacetates (178), butyl boronates (179) trimethylsilyl derivatives, or cycHc acetals offers a means both for identifying individual compounds and for separating mixtures of polyols, chiefly by gas—Hquid chromatography (glc). Thus, sorbitol in bakery products is converted to the hexaacetate, separated, and determined by glc using a flame ionisation detector (180) aqueous solutions of sorbitol and mannitol are similarly separated and determined (181). Sorbitol may be identified by formation of its monobensylidene derivative (182) and mannitol by conversion to its hexaacetate (183). 

Owing to poor volatihty, derivatization of nicotinic acid and nicotinamide are important techniques in the gc analysis of these substances. For example, a gc procedure has been reported for nicotinamide using a flame ionisation detector at detection limits of - 0.2 fig (58). The nonvolatile amide was converted to the nitrile by reaction with heptafluorobutryic anhydride (56). For a related molecule, quinolinic acid, fmol detection limits were claimed for a gc procedure using either packed or capillary columns after derivatization to its hexafluoroisopropyl ester (58). 

The most widely used method of analysis for methyl chloride is gas chromatography. A capillary column medium that does a very good job in separating most chlorinated hydrocarbons is methyl siUcone or methyl (5% phenyl) siUcone. The detector of choice is a flame ionisation detector. Typical molar response factors for the chlorinated methanes are methyl chloride, 2.05 methylene chloride, 2.2 chloroform, 2.8 carbon tetrachloride, 3.1, where methane is defined as having a molar response factor of 2.00. Most two-carbon chlorinated hydrocarbons have a molar response factor of about 1.0 on the same basis. 

The alkah flame-ionisation detector (AFID), sometimes called a thermionic (TID) or nitrogen—phosphoms detector (NPD), has as its basis the fact that a phosphoms- or nitrogen-containing organic material, when placed ia contact with an alkaU salt above a flame, forms ions ia excess of thermal ionic formation, which can then be detected as a current. Such a detector at the end of a column then reports on the elution of these compounds. The mechanism of the process is not clearly understood, but the enhanced current makes this type of detector popular for trace analysis of materials such as phosphoms-containing pesticides. 

Detectors. The function of the detector in HPLC is to monitor the mobile phase as it emerges from the column. The detection process in liquid chromatography has presented more problems than in gas chromatography there is, for example no equivalent to the universal flame ionisation detector of gas chromatography for use in liquid chromatography. Suitable detectors can be broadly divided into the following two classes ... 

Compared with the flame ionisation detector, however, the ECD is more specialised and tends to be chosen for its selectivity which can simplify chromatograms. The ECD requires careful attention to obtain reliable results. Cleanliness is essential and the carrier gases must be very pure and dry. The two most likely impurities in these gases are water and oxygen which are sufficiently electronegative to produce a detector response and so give a noisy baseline. 

Apparatus. A gas chromatograph equipped with a flame-ionisation detector and data-handling system. The use of a digital integrator is particularly convenient for quantitative determinations, but other methods of measuring peak area may be used (Section 9.4). 

Ethanol concentration in the fermentation broth is determined by using gas chromatography (HP 5890 series II with HP Chemstation data processing software, Hewlett-Packard, Avondale, PA) with a Poropak Q Column, and a Hewlett-Packard model 3380A integrator. A flame ionisation detector (FID) is used to determine ethanol. The oven temperature is maintained at 180 °C, and the injector and detector temperature are maintained at 240 °C. The sample taken from the fermentation media has to be filtered and any internal standard must be added for analysis based on internal standard methods otherwise, the area under the peak must be compared with known standard samples for calculation based on external standard methods. 

After passing through the column, the separated solutes are sensed by an in-line detector. The output of the detector is an electrical signal, the variation of which is displayed on a potentiometric recorder, a computing integrator or a vdu screen. Most of the popular detectors in hplc are selective devices, which means that they may not respond to all of the solutes that are present in a mixture. At present there is no universal detector for hplc that can compare with the sensitivity and performance of the flame ionisation detector used in gas chromatography. Some solutes are not easy to detect in hplc, and have to be converted into a detectable form after they emerge from the column. This approach is called post-column derivatisation. 

Two GC columns Porapak Q (for C02 and water analyses) and Molecular sieve 5A (hydrogen, oxygen, and CO) were used with two thermal conductivity detectors and another GC column with modified y-Al203 (methane, ethane, ethene, propane, propene, and C4 hydrocarbons) was used with a flame ionisation detector. Carbon and oxygen balances were within 100+5%. 

Rasmussen [82] describes a gas chromatographic analysis and a method for data interpretation that he has successfully used to identify crude oil and bunker fuel spills. Samples were analysed using a Dexsil-300 support coated open tube (SCOT) column and a flame ionisation detector. The high-resolution chromatogram was mathematically treated to give GC patterns that were a characteristic of the oil and were relatively unaffected by moderate weathering. He compiled the GC patterns of 20 crude oils. Rasmussen [82] uses metal and sulfur determinations and infrared spectroscopy to complement the capillary gas chromatographic technique. 

Iodoethanes are separated on a glass-lined, stainless-steel column (2mx3.2mm o.d.) packed with 10% OV-101 on Chromosorb W HP (150— 190m), using flow-rates of 90ml min-1 for the carrier gas (N ) and 35 and 350ml min-1 for H and air, respectively, for the flame-ionisation detector. Set the injection port, detector and column temperatures at 140, 130 and 60°C, respectively. 

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