Flame ionization detector, hydrocarbon analysis

This type of analysis requires several chromatographic columns and detectors. Hydrocarbons are measured with the aid of a flame ionization detector FID, while the other gases are analyzed using a katharometer. A large number of combinations of columns is possible considering the commutations between columns and, potentially, backflushing of the carrier gas. As an example, the hydrocarbons can be separated by a column packed with silicone or alumina while O2, N2 and CO will require a molecular sieve column. H2S is a special case because this gas is fixed irreversibly on a number of chromatographic supports. Its separation can be achieved on certain kinds of supports such as Porapak which are styrene-divinylbenzene copolymers. This type of phase is also used to analyze CO2 and water. 

The most widely used method of analysis for methylene chloride is gas chromatography. A capillary column medium that does a very good job in separating most chlorinated hydrocarbons is methyl silicone or methyl (5% phenyl) silicone. The detector of choice is a flame ionization detector. Typical molar response factors for the chlorinated methanes ate methyl chloride, 2.05 methylene chloride, 2.2 chloroform, 2.8 and 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. 

Noncondensable gases leaving the condensation vessels were depressurized (by means of an electronic back-pressure, Brooks Instrument model 5866), totalized (by means of an on-line flow gas meter, Ritter model TG05-5), and periodically analyzed with an on-line GC (Hewlett-Packard model 6890) equipped with three columns and two detectors for the analysis of Cj-C10 hydrocarbons (A1203 plot capillary column connected to a flame ionization detector), H2, CH4,... 

The analysis of organosulphur compounds has been greatly facilitated by the flame photometric detector [2], Volatile compounds can be separated by a glass capillary chromatographic column and the effluent split to a flame ionization detector and a flame photometric detector. The flame photometric detector response is proportional to [S2] [3-6]. The selectivity and enhanced sensitivity of the flame photometric detector for sulphur permits quantitation of organosulphur compounds at relatively low concentrations in complex organic mixtures. The flame ionization detector trace allows the organosulphur compounds to be referenced to the more abundant aliphatic and/or polynuclear aromatic hydrocarbons. 

A water-cooled sampling probe of internal diameter 1 mm and external diameter 5 mm with a 3-meter long heated line was used to measure concentrations of unburned hydrocarbon (flame ionization detector, Analysis Automation, 520) and NOj (chemiluminescence analyzer, Thermal Environment Instruments, 42) at the combustor exit on a wet basis. The former, measured to a precision of the order of 1 ppm, was used to ensure complete consumption of fuel within the duct, and the latter with a precision of around 0.2 ppm was used to quantify the effect of oscillations on NOj. emissions. 

Mass Spectrometry. The use of a quadrupole mass spectrometer as a GC detector for nonmethane hydrocarbon analysis has come of age in recent years. Development of capillary columns with low carrier gas flows has greatly facilitated the interfacing of the GC and mass spectrometer (MS). The entire capillary column effluent can be dumped directly into the MS ion source to maximize system sensitivity. GC-MS detection limits are compound-specific but in most cases are similar to those of the flame ionization detector. Quantitation with a mass spectrometer as detector requires individual species calibration curves. However, the NMOC response pattern as represented by a GC-MS total ion chromatogram is usually very similar to the equivalent FID chromatogram. Consequently, the MS detector can... 

Product analysis. Product analysis from both systems was carried out on a Hewlett-Packard 5890 series II gas chromatograph fitted with a flame ionization detector. Separation of the C, to C8 hydrocarbons... 

Flame ionization detector (FID) requires a carbon—hydrogen bond. Compounds are ionized by a flame as they exit the column, thus making further analysis impossible. It is applicable to all organic compounds, but because of its lack of sensitivity (ppm range) and specificity, it is usually used for hydrocarbon analysis. 

Naphtha componential analysis of C3-C9 hydrocarbons was done on a 200-ft Squalane capillary column with a flame ionization detector (FID). 

All product analysis of effluent gas streams was performed by on-line gas chromatography. Two different gas chromatographs were employed, each with heated sample valve connected to the reactor effluent stream. Analysis of light (Ci-C5) hydrocarbons and dimethyl ether was performed by a Varian 1400 GC equipped with flame ionization detector. Separation of the products was accomplished by a 20 column (1/8" O.D.) packed with Porapak Q. Analysis of hydrocarbons in the C5 to... 

The reactor effluent was analyzed by on-line GC-analysis prior to condensation. Each reactor line was equipped with a HP 5890 GC with flame ionization detector (FID), interfaced with a PC for data handling and storage. The method of analysis, based on HP s PONA analysis, included all important hydrocarbons up to C,. Heavier components than this were only present in trace amounts, and were not analyzed. Research octane numbers (RON) were calculated from GC-analysis based on an adapted version of the method presented by Anderson et al. (5). The hydrogen yield was calculated from GC-analysis as the hydrogen balance over the reactor. 

The concentrations of hydrocarbon at the inlet and outlet of the reactor were measured using FTIR (Nicolet) with a meicury-calcium-telluride (MCT) detector, which was cooled by liquid nitrogen and gas cell (Infrared Analysis), and with 16 scans and a resolution of 2 cm. The concentrations were also checked using GC (HP3890plus) with FID (flame ionization detector) and HP plot column. The vapor pressures of the hydrocarbons were calculated by using Reid equation [6]. 

Gas chromatography was employed for analysis of the reaction products Hi, CO and CO2 were analyzed by thermal-conductivity detector (TCD) methanol, dimethyl ether, methyl formate and hydrocarbons were analyzed by the flame ionization detector (FID). 

The aromatic hydrocarbon content of diesel fuel affects the cetane number and exhaust emissions. One test method (ASTM D-5186) is applicable to diesel fuel and is unaffected by fuel coloration. Aromatics concentration in the range 1-75 mass% and polynuclear aromatic hydrocarbons in the range 0.5-50 mass% can be determined by this test method. In the method, a small aliquot of the fuel sample is injected onto a packed silica adsorption column and eluted with supercritical carbon dioxide mobile phase. Mono- and polynuclear aromatics in the sample are separated from nonaromatics and detected with a flame ionization detector. The detector response to hydrocarbons is recorded throughout the analysis time. The chromatographic areas corresponding to the mononuclear aromatic constituents, polynuclear aromatic constituents, and nonaromatic constituents are determined, and the mass-percent content of each of these groups is calculated by area normalization. 

Continuous analysis instruments equipped with flame ionization, chemiluminescence, and infrared detectors were used to measure the concentrations of total hydrocarbons, nitrogen oxides and carbon monoxide, respectively. The concentration of total hydrocarbons was measured by a JUM FID 3-300 hydrocarbon analyzer with a flame ionization detector. NO, NO2 and NOx was measured by an ECO Physics CLD 700 EL-ht chemiluminescence detector. CO was measured with either a Beckman Industrial Model 880 non-dispersive infrared instrument or an NDIR instrument from Maihak (UNOR 6N). 

Gas chromatographs equipped with flame ionization and thermal conductivity detectors gave detailed information on concentrations of oxygenated compounds, hydrocarbons etc., online in a semi-continuous manner. For the analysis of the hydrocarbons either a Varian Star 3400 CX or a Shimadzu GC-3BF with flame ionization detectors was used. N2, O2 and CO2 were measured with a Shimadzu GC-3BT equipped with a thermal conductivity detector. 

Analysis. Heavy Products. High molecular weight hydrocarbons were analyzed by gas-liquid chromatography. A known volume of undecane was added to the irradiated sample as internal standard. The stationary phase was silicone oil on Chromosorb W. The column was 1.50 meters long its diameter was 3 mm. A flame ionization detector was used. 

Accurate g.l.c. analysis of mixtures of substances with a flame ionization detector (f.i.d.) depends upon a knowledge of the relative detector response of each compound. Variations in the f.i.d. responses of steroids in molar terms have now been put on a quantitative basis. There is a good linear relationship between molar f.i.d. response and the effective carbon number , which is the number of carbon atoms per molecule less half the number of oxygen atoms (over the ranges Ci8—C31, and Oo—O4). This behaviour parallels earlier conclusions for paraffin hydrocarbons, alcohols, and esters. G.l.c. data are reported for the trimethylsilyl ethers of 49 plant sterols on eight different columns. ... 

With the aid of the carrier gas flow the trace zone was transferred into the analytical column. Under such conditions carbon dioxide is completely retained by diethanolamine. The concentration and analysis were performed at room temperature. The separated trace components were sensed by a flame-ionization detector. The carrier gas (nitrogen) flow-rate was 60 ml/min. For regeneration the concentration column was heated in the carrier gas flow at 100—105°C for 5—7 min. For heating and cooling a special device forming part of a KhT-2M chromatograph manufactured in the U.S.S.R. was used. The duration of the total analytical cycle was 25 min. This method permits the determination of hydrocarbon gases in carbon dioxide at concentrations down to 10" %. 

Cylinders of the flashed gas were analysed for hydrocarbon gas composition on a Carle gas chromatograph (GC) system equipped with both a thermal conductivity detector (TCD) and a flame ionization detector (FID). An offline preparation system and dual inlet mass spectrometer (MS) were used to analyse the carbon and hydrogen isotopic values of hydrocarbon components. A customized Gow Mac GC was interfaced with a vacuum/combustion system to separate hydrocarbons from other components and combust to CO2 and water that were purified and sealed into Pyrex tubes for isotopic analysis. The CO2 was analysed directly on one of three dual inlet mass spectrometers Finnigan Delta S, Finnigan Delta + XL or VG SIRA II. The water was reacted with zinc turnings and converted to hydrogen gas, which was analysed on either the Delta S or Delta + XL MS. 

Carbon monoxide may be determined over a wide range of concentration via infrared analysis [25]. Good results are achieved at concentrations as low as 1.25 to 2.5 mg m . The main disadvantage of this technique is the non-linear response, as well as possible interference by CO2, water vapour and hydrocarbons. The use of the gas chromatography for determining CO includes a catalytic reduction system, which converts carbon monoxide quantitatively to methane and a flame ionization detector. For a rapid CO determination, indicator tubes with palladium salt as a catalyst and silicomolybdate complex, which yields a blue colour with carbon monoxide, are used. The CO determination can also be carried out on the basis of its reaction with the radioactive kryptonate of palladium chloride [18, 25]. 

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