Gas chromatography detectors flame ionization

Fractions containing 2 of ca. >90% purity by gas chromatography flame ionization detector) were combined. 

A gas chromatography-flame ionization detector system can be nsed for the separation and detection of nonpolar organic componnds. Semivolatile constitnents are among the analytes that can readily be resolved and detected nsing the system. If a packed column is used, four pairs of compounds may not be resolved adequately and are reported as a quantitative sum anthracene and phenanthrene, chrysene and benzo[a]anthracene, benzo[/ ]fluoranthene and benzo[/ ]fluoranthene, and dibenzo[a,/i]anthracene and indeno[l,2,3-cd]pyrene. This issue can be resolved through the use of a capillary column in place of a packed column. 

Biological tissues Add water to tissue sample (at 50 C) and homogenise extract with carbon disulfide and analyze Gas chromatography flame ionization detector 0.5 ag/g No data Letz et al. 1984... 

Gas chromatography flame ionization detector c Laboratory water and effluents 01 Gas chromatography mass spectrometry e Laboratory water NS, not specified... 

GC = gas chromatography GC/MS = gas chromatography/mass spectrometry GC/EICD = gas chromatography/electroLytic conductivity detector GC/PID = gas chromatography/photoionization detector GC/ECD = gas chromatography/electron captive detector GC/FID = gas chromatography/flame ionization detector RSD = relative standard deviation ppb = part per billion ppt = parts per trillion. 

Gas chromatography-flame ionization detector Gas chromatography/liquid chromatography-mass spectrometry... 

MINICAMS Gas chromatography-flame ionization detector (GC-FID) OI analytical... 

Several experimental techniques can be used to study transport phenomena in polymers nuclear magnetic resonance imagiug (NMR), UV spectrophotometer, gas chromatography/flame ionization detector (GCMD), high-performance liquid chromatography (HPLC), laser interferometry, gravimetric method and Fourier Transform Infra-Red spectroscopy (FTIR). 

HS, headspace measured by gas chromatography flame ionization detector (GC-FID) using a large-volume injection system (Ref. 11). This is regarded as the tme gas phase concentration. Solid-phase microextraction (SPME) sampling time. 

Acrylonitrile in both biological and environmental samples is most commonly determined by gas chromatography with a nitrogen-phosphorus detector (GC/NPD) (Page 1985), gas chromatography/flame ionization detection (GC/FID) (EPA 1982a), or gas chromatography/mass spectroscopy (GC/MS) (Anderson and Harland 1980). Infrared spectroscopy (Jacobs and Syrjala... 

The key sample set selection for analytical method development has been discussed at length in Chapter 7. There are a great variety of methods used for monitoring impurities.1,2 The primary requirement for such techniques is the capacity to differentiate between the compounds of interest. This requirement frequently necessitates utilization of separation methods (covered in Section V. C) in combination with a variety of detectors (Section V. B). For gas chromatography, flame ionization and electron capture detectors are commonly used. However, these detectors are not suitable for isolation and characterization of impurities, which require... 

Figure 6-13 Schematic diagram of an FID equipped with make-up gas. FID, Flame ionization detector. (Modified from Hyver KJ High resolution gas chromatography, 3rd edition, Palo Alto Calif Hewlitt Packard, 1989.)...

Analysis. Free fatty acids were ethylated in ethanol dehydrated with molecular sieves using gaseous HCl as the catalyst. Ethyl esters of fatty acids were analyzed on a DB-23 capillary column (0.25 mm x 30 m J W Scientific, Folsom, CA) connected to a Hewlett-Packard 5890 gas chromatograph (Avondale, PA) as described previously (19). The water content in the oil layer was determined by Karl Fisher titration (moisture meter CA-07 Mitsubishi Chemical, Tokyo, Japan). The contents (by weight) of free fatty acids and fatty acid ethyl esters were analyzed by a thin-layer chromatography/flame ionization detector... 

Purity of monomeric plasticizers can be determined with a high precision using gas chromatography. Flame ionization or thermal conductivity detectors are used. Capillary... 

Despite their importance, gas chromatography and liquid chromatography cannot be used to separate and analyze all types of samples. Gas chromatography, particularly when using capillary columns, provides for rapid separations with excellent resolution. Its application, however, is limited to volatile analytes or those analytes that can be made volatile by a suitable derivatization. Liquid chromatography can be used to separate a wider array of solutes however, the most commonly used detectors (UV, fluorescence, and electrochemical) do not respond as universally as the flame ionization detector commonly used in gas chromatography. 

Fig. 3. (a) Flame ionization detector (fid) response to an extract of commercially processed Valencia orange juice, (b) Gas chromatography—olfactometry (geo) chromatogram of the same extract. The abscissa in both chromatograms is a normal paraffin retention index scale ranging between hexane and octadecane (Kovats index). Dilution value in the geo is the -fold that the extract had to be diluted until odor was no longer detectable at each index. 

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. 

For selective estimation of phenols pollution of environment such chromatographic methods as gas chromatography with flame-ionization detector (ISO method 8165) and high performance liquid chromatography with UV-detector (EPA method 625) is recommended. For determination of phenol, cresols, chlorophenols in environmental samples application of HPLC with amperometric detector is perspective. Phenols and chlorophenols can be easy oxidized and determined with high sensitivity on carbon-glass electrode. 

Epichlorhydrin (ECH) detection starts with detecting epoxide cycle using hydrochloric acid in combination with sodium chloride the reaction product - 1,3-dichlorhydrin - is extracted in diethyl ether and concentrated by removing the latter. Gas-liquid chromatography with a flame-ionization detector is used to detect glycerin 1,3-dichlorhydrin. The sensitivity of the method is 0.01 mg/dm. ... 

Historically, measurements have classified ambient hydrocarbons in two classes methane (CH4) and all other nonmethane volatile organic compounds (NMVOCs). Analyzing hydrocarbons in the atmosphere involves a three-step process collection, separation, and quantification. Collection involves obtaining an aliquot of air, e.g., with an evacuated canister. The principal separation process is gas chromatography (GC), and the principal quantification technique is wdth a calibrated flame ionization detector (FID). Mass spectroscopy (MS) is used along with GC to identify individual hydrocarbon compounds. 

By using a flame ionization detector (FID), most compounds having a bond of carbon and hydrogen can be measured. This detector was originally developed for gas chromatography and employs a sensitive electrometer that measures the change in ion intensity resulting from the combustion of air... 

Figure 10.4 Schematic representation of the multidimensional GC-IRMS system developed by Nitz et al. (27) PRl and PR2, pressure regulators SV1-SV4, solenoid valves NV— and NV-I-, needle valves FID1-FID3, flame-ionization detectors. Reprinted from Journal of High Resolution Chromatography, 15, S. Nitz et al, Multidimensional gas cliro-matography-isotope ratio mass specti ometiy, (MDGC-IRMS). Pait A system description and teclinical requirements , pp. 387-391, 1992, with permission from Wiley-VCFI.

One example of normal-phase liquid chromatography coupled to gas chromatography is the determination of alkylated, oxygenated and nitrated polycyclic aromatic compounds (PACs) in urban air particulate extracts (97). Since such extracts are very complex, LC-GC is the best possible separation technique. A quartz microfibre filter retains the particulate material and supercritical fluid extraction (SPE) with CO2 and a toluene modifier extracts the organic components from the dust particles. The final extract is then dissolved in -hexane and analysed by NPLC. The transfer at 100 p.1 min of different fractions to the GC system by an on-column interface enabled many PACs to be detected by an ion-trap detector. A flame ionization detector (PID) and a 350 p.1 loop interface was used to quantify the identified compounds. The experimental conditions employed are shown in Table 13.2. 

The purity of 1 and 2 is assessed by analytical gas-liquid chromatography (GC) on a Hewlett-Packard 5890 gas chromatograph equipped with a flame-ionization detector and fitted with a 50 m x 0.2 mm HP-5 fused silica glass capillary column using linear temperature programming from an initial temperature of 150°C for 5 min to a final temperature of 200°C for 10 min at a rate of 5°C/min. 

Slagt et al. [134] have stated that because of their thermal instability and reactivity sultones could not be easily analyzed by gas chromatography. They studied the two methods published by Martinsson and Nilsson using a Carlo Erba Fractovap G1 equipped with a flame ionization detector and a glass column (length 0.65 m OD 1/4 in.) filled with 10% OV 1 on Chromosorb W-AW (80-100 mesh). The column temperature was 230°C and the injector/de-tector temperature 275°C. The gas flow rates were N2 25 ml/min (carrier gas), H2 25 ml/min, and air 250 ml/min. One microliter of sample was injected. 

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