Flame ionization detector modifications

The FID may be operated as an element-selective detector after minor modification. The hydrogen atmosphere flame ionization detector (HAFID) can be made selective towards organometalllc... 

A disadvantage of most organic modifiers is their incompatibility with the popular flame ionization detector (FID). We are presently investigating the modification of carbon dioxide with small amounts of highly oxidized, polar compounds that are invisible to the FID, such as formic acid. Our results with formic acid, at concentrations of about 0.3,0.5, and 0.7% (w/w) in CO2, may be summarized as follows (15), (Crow and Foley, manuscript in preparation) The addition of formic... 

Determine the composition profile of fatty acids as directed under Fatty Acid Composition, Appendix VII, with the following modifications (1) In the Sample Preparation, use about 55 mg of sample per 10 mL, and (2) in the Procedure, use a suitable capillary gas chromatograph (see Chromatography, Appendix IIA), equipped with a flame ionization detector, a 60-m x 0.25-mm (id) column, or equivalent, coated with a 0.20-p.m layer of 2-cyanopropylpolysiloxane (Supelco SP-2340, or equivalent), a capillary injection port (split mode, operated at a split ratio of 1 100), and an integrator. Set the initial column temperature at 150°, heat at a rate of 1.3°/min to 225°, and hold at 225° for 10 min. Set the injection port temperature to 210° and the detector to 230°. Set the carrier gas flow rate at 25 cm/s. 

Emissions-measuring instruments used in this program consisted of non-dispersive infrared (NDIR) analyzers for CO, CO2, and NO. A modified flame ionization detector (FID) was used to measure HC. Modifications insured that the instrument would detect the unbumed... 

Since both the flame-photometric and thermionic detectors are the flame-type detectors, similar rules apply for their coupling with capillary columns as for the flame ionization detector no special modifications are required. 

Lipid Composition. After the behavior experiments, the rats were killed by decapitation. Tissue samples including brain and retina were removed and stored at -80°C. The total lipid extracts of tissues were prepared according to the method of Folch et al. (39). Butylated hydroxytoluene (300 qg/sample) was added in methanol to each sample to minimize lipid oxidation. The total lipid extracts were trans-methylated with 14% BFj/methanol at 100°C for 60 min by a modification (40) of the method of Morrison and Smith (41). Fatty acid methyl esters were then analyzed on a Hewlett-Packard 5890 gas chromatograph (Hewlett-Packard, Palo Alto, CA) equipped with a flame ionization detector and fused silica capillary column (DB-FFAP, 30 m X 0.25 mm x 0.25 m, J W, Folsom, CA) with carrier gas (hydrogen) at a linear velocity of 50 cm/s. Injector and detector temperature were set to 250°C and oven temperature program was as follows 130 to 175°C at4°C/min, 175 to 210°C at l°C/min, and then to 245 at 30°C/min, with a final... 

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