FID Detector

It is crucial in quantitative GC to obtain a good separation of the components of interest. Although this is not critical when a mass spectrometer is used as the detector (because ions for identification can be mass selected), it is nevertheless good practice. If the GC effluent is split between the mass spectrometer and FID detector, either detector can be used for quantitation. Because the response for any individual compound will differ, it is necessary to obtain relative response factors for those compounds for which quantitation is needed. Care should be taken to prevent contamination of the sample with the reference standards. This is a major source of error in trace quantitative analysis. To prevent such contamination, a method blank should be run, following all steps in the method of preparation of a sample except the addition of the sample. To ensure that there is no contamination or carryover in the GC column or the ion source, the method blank should be run prior to each sample. 

HPA catalyzed liquid phase nitration was eairied out in a Teflon-lined stainless autoclave of 200 mL equipped with a magnetic stirrer. Reactants and HPA were quantitatively added to the autoclave, which was sealed and heated in an oil-bath. Products were analyzed by GC with OV-101 30 m capillary column and FID detector by using calibrated area normalization and internal standard method. All products were confirmed by GC-MASS analysis. 

The products of the oxidation reaction were analysed by gas chromatography (Hewlett Packard, 5880 A), employing a FID detector and equipped with a capillary column (50 m x 0.25 mm crosslinked methyl silicone gum). The reactants and products of n-hexane oxidation were analysed by gas chromatography (Hewlett Packard, 5890) equipped with a FFAP column (30 m X 0.25 mm). The identity of the products was further confined by GC-MS (Shimadzu QCMC-QP 2000A). 

Hydrolytic Kinetic Resolution (HKR) of epichlorohydrin. The HKR reaction was performed by the standard procedure as reported by us earlier (17, 22). After the completion of the HKR reaction, all of the reaction products were removed by evacuation (epoxide was removed at room temperature ( 300 K) and diol was removed at a temperature of 323-329 K). The recovered catalyst was then recycled up to three times in the HKR reaction. For flow experiments, a mixture of racemic epichlorohydrin (600 mmol), water (0.7 eq., 7.56 ml) and chlorobenzene (7.2 ml) in isopropyl alcohol (600 mmol) as the co-solvent was pumped across a 12 cm long stainless steel fixed bed reactor containing SBA-15 Co-OAc salen catalyst (B) bed ( 297 mg) via syringe pump at a flow rate of 35 p,l/min. Approximately 10 cm of the reactor inlet was filled with glass beads and a 2 pm stainless steel frit was installed at the outlet of the reactor. Reaction products were analyzed by gas chromatography using ChiralDex GTA capillary column and an FID detector. 

In chromatography-FTIR applications, in most instances, IR spectroscopy alone cannot provide unequivocal mixture-component identification. For this reason, chromatography-FTIR results are often combined with retention indices or mass-spectral analysis to improve structure assignments. In GC-FTIR instrumentation the capillary column terminates directly at the light-pipe entrance, and the flow is returned to the GC oven to allow in-line detection by FID or MS. Recently, a multihyphenated system consisting of a GC, combined with a cryostatic interfaced FT1R spectrometer and FID detector, and a mass spectrometer, has been described [197]. Obviously, GC-FTIR-MS is a versatile complex mixture analysis technique that can provide unequivocal and unambiguous compound identification [198,199]. Actually, on-line GC-IR, with... 

A Fidamat 5E-I to follow the total concentration in HC (and CxHyOz) with a FID detector. 

The reaction products were analyzed using an on-line gas chromatograph (HP 6890) equipped by a FID detector and a capillary column DB-5 for toluene alkylation while HP-INNOWax, was used for toluene disproportionation. 

Chromatography. Compounds of essential oil were determined by the means HEWLETT -PACKARD 5890 Series 11 system, with capillary coluttm HP-5, FID detector, Split-spht less system for injection and automatic injector HP 7673. 

Simulated distillation analysis was carried out on the extract and filtrate produced after precipitation, focusing on the fractions which boiled below 350°C. A Perkin Elmer model 8500 GC fitted with a wide-bore, OV-1 capillary colunm, 25 m long and 0.53 pm in diameter, was used. The oven temperature was held at 40 C for 1 minute and then increased at a rate of 4 C per minute to 250 C, where the temperature was held. There was no split on the injection and a FID detector was used. Initial fractionation of the samples was carried out by vacuum distillation. 

The activity of calcined HTs was determined in self-condensation reaction of acetone (J.T. Baker) by using a fixed bed catalytic reactor with an on-line GC. Prior to the catalytic test, catalysts were pretreated in-situ under nitrogen atmosphere at 450°C for 5h. Acetone was supplied to the reactor by bubbling nitrogen gas through the acetone container at 0 °C. The reaction temperature was established at 200 C. The products were analyzed by means of GC (Varian CP-3800) using a WCOT Fused silica column, equipped with a FID detector. 

The reaction products were analyzed by on-line gas chromatography (HP 5890 GC) equipped with both TCD and FID detectors. GC column used is GS-Q 30 m manufactured by JW Scientific. Temperature program of 5°C/min to 300°C was chosen for the analysis. Liquid products were collected in a cold trap at -3°C and were also analyzed by GC-mass spectrometry. 

Batch slurry reactions were carried out in liquid phase in a stirred glass vessel with condenser. Catalyst was added to a preheated solution containing aromatic reactant (35ml, Aldrich) and iso-butyric anhydride (16ml, Aldrich) in a 3 1 molar ratio. Samples of the reaction mixture were removed from the reaction mixture after various reaction times, filtered and analysed by gas chromatography (column DB-5, 30m, He carrier gas, FID detector) to determine reaction progress. Product identification was made by comparison with appropriate reference materials. 

It is important to ensure that the data collection rate is fast enough for peaks with low retention times in order to ensure good reproducibility of all peak parameters. For modern instrumentation, this is generally not a problem for example, FID detectors are typically able to achieve a data acquisition rate of 50-250 Hz using the standard instrument configuration. 

In the case of methyl (Z)-a-acetamido cinnamate (B) the reaction mixture was passed through a short silicagel column to remove the catalyst. The ee was determined on CP-CHIRASIL-L-VAL column [25 m, internal diameter 0.25 mm, film thickness 0.12 pm, carrier gas 100 kPa nitrogen, FID detector the retention times of the enantiomers are 32.5 min (R), 34.2 min (5)]. 

The FID detector, for which the signal depends on the instantaneous mass flow, is essentially free from variations due to flow rate that can cause errors in detectors whose response is a function of the instantaneous molar concentration (Fig. 2.11). 

Figure 2.11—(a) FID detector (b) NPD detector and (c) effect of flow rate on detector signal and difference between the mass flow detector and concentration dependent detector. 1, normal situation (constant flow) 2, mass flow detection (i.e. FID) with an interruption in the flow rate (the area remains constant) 3, TCD detection with an interruption in the flow rate (the area does not represent the mass of the compound flowing through the detector). 

Catalytic activities for n-hexane cracking were performed using an isothermally operated flow reactor. The feed stream of nitrogen was saturated at 3°C with hexane. With the help of a bypass it was possible to determine both the reactor inlet and outlet concentration of hexane using a gas chromatograph (Varian Star 3400) with FID-detector. 

The catalytic activity for dehydration of iso-propanol on PSM and AMM samples was studied in a quartz microreactor. 0.2 g catalyst was used for each run. Isopropanol was introduced to the reactor by a helium flow (20 ml/min) which was saturated with iso-propanol vapor at room temperature. The reaction product was analyzed by HP6890 GC equipped with a FID detector. 

GC analyses were performed on an Intersmat IGC 121 FL instrument equipped with a FID detector (column 1.5 m x 1/8" of 10% SE30 on Chromosorb Q (80-100 mesh) carrier gas nitrogen (20 ml-min-1) temperature programming 9.5 min at 100°C, then increase to 200°C at a rate of 15°C min-1) using decane as internal standard. 

All the reaction products were analyzed by gas chromatography with a FID detector. The specific activity As is determined by the relation As=(Qx)/m, where Q = hydrocarbon flow, m = catalyst weight and x = total conversion. For all the samples studied, the conversion was kept lower than 15% by adjusting the catalyst weight. 

Figure D1.2.2 Sample GC chromatogram of the FAME from butter fat (Sweet Cream Butter, Wisconsin Grade AA, Roundy s, Milwaukee, Wise.) prepared using the sodium methoxide method (see Basic Protocol 2). Equipment DB-23 fused silica capillary column, 30 m x 0.32 mm i.d., 0.25 pm film thickness, FID detector. Temperature, injector 225°C detector 250°C. Column (oven) temperature program 100°C initial, hold 4 min, ramp to 198°C at 1.5°C/min, hold 10 min. Total run time was 80 min. Split injection.

High-resolution gas chromatograph fitted with the appropriate chiral column (e.g., heptakis(2,3-di-0-methyl-6-(9-t-butyldimethylsilyl)-(3-cyclodextrin in poly(14% cyanopropylphenyl/86% dimethylsiloxane)), a stationary phase widely used for the chiral analysis of many food extracts Hydrogen and air lines FID detector on-column injector is preferred... 

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