Head-space gas chromatograph

Head-space gas chromatographic determination of isovaleraldehyde Dried carrot samples(0.5 g) were... 

L. Gramiccioni, M. Milana, and S. DiMarzio, A head space gas chromatographic method for the determination of traces of ethylene oxide in sterilized medical devices, Microchem. J., 32 89-93 (1985). 

These cases can be most frustrating to the analyst for a negative report cannot be given when there is a most obvious detectable abnormal odour whose source has not been identified. If the material has a distinct odour, a comparative head-space gas chromatographic screen is indicated. 

Fis. 12.13 Automated head space gas chromatograph, (a) Thermostating position, (b) Introduction of gas carrier into ths vial, (c) Injection position. (Courtesy of Perkin Elmer). 

International Standards Organization, 1997a. Water quality - Determination of benzene and some derivatives, Part 1 Head-space gas chromatographic method. ISO 11423-1 1997. 

F. Angerosa, L. Di Giacinto, R. Wo, S. Cumitini, Sensory evaluation of virgin olive oils by artificial neural network processing of dynamic head-space gas chromatographic data. J. Sd. Food Agric. 72,323-328 (1996)... 

Simple and Ultrasensitive Head-Space Gas Chromatographic Method for the Assay of Fluorocarbon Propellants in Blood... 

Head Space Gas Chromatographic Analysis of Paraldehyde in Toxicological Specimens... 

Ohno, H. Aoyama, J. and Kishimoto, H. Simultaneous determination of volatile organic compounds by head space gas-chromatographic analysis with dual detection. Japanese Journal of Toxicology and Environmental Health 1992, 38, 84-92. 

B. D. Page and G. Lacroix, Application of solid-phase microextraction to the head-space gas chromatographic analysis of halogenated volatiles in selected foods. J. Chrom. 648 199-211 (1993). 

Ozeris, S., and R. Basselle Quantitative Study of Gas Chromatographic Analysis of Head Space Gas of Dilute Aqueous Solutions. Analyt. Chemistry 35, 1091 (1963). 

Samples are placed either in new quart paint cans or quart fruit jars (Figure E26-1). The containers containing the samples are heated in an oven to about 120 "C for 20 minutes to drive the traces of accelerant from the sample. A hole is punched in the lid (do this before heating and cover it with a septum), and 2 mL of head space gas is examined with a gas chromatograph fitted with an FID detector. 

A gas-tight syringe is placed in the septum covering, and a 2.0 mL sample of head space gas is obtained and injected into the chromatograph. A 1.8 m x 3 mm i.d. SS column packed with 10 % SE-30 on 60-80 mesh Chromosorb-W is used to separate the components. Be sure to do the blank in the same manner, and do as many standards as you feel necessary. 

Gas Chromatographic Blood Alcohol Determination by the Head Space Gas Analysis Method... 

Simple Gas Chromatographic Determination of Acetone and B Ketobutyric Acid in Blood Serum by Means of Head Space Gas Sampling Clin. Chim. Acta 28(2) 233-237 (1970) CA 73 21996b... 

Bassette, R. Oezeris, S. and Whitnah, C.H. Gas-chromatographic analysis of head space gas of dilute aqueous solutions. Analytical Chemistry 1962,34,1540-1543. 

In this method the polymer is heated to 300 C in a sealed tube in the absence of solvents. The head space gas in the tube is then swept into a gas chromatograph where the individual aromatics are determined. The method is cdibrated against standard injections of pure aromatics into the gas chromatograph. 

At each sampling period, 5 mL of solution and 50 pi of head space gas from the solution reservoir was extracted and analyzed. The solution was spiked with 50 pL of 1000 ppm benzene-D6 as a internal standard. Afterwards, the sample was shaken in a head space sampler (HP 7694E) at 70 °C for 20 minutes. The concentrations of vinyl chloride, DCE isomers, TCE, and other chlorinated products that could be daughter products of TCE were analyzed with a gas chromatograph (HP 6890) equipped with a mass selective detector (HP 5973). After the analysis of organic compounds, pH was measured and the chloride concentration in the sample was analyzed with a Capillary Ion Analyzer (Waters CIA). The 50 pi of head space gas was directly injected into a GC (HP 6890) with a HP Plot/Al203 column (50m x 0.53 mm x 15 pm) and the concentrations of methane, ethane, ethylene, and acetylene were quantified with a FID detector. 

Wolf and cowoikers" " applied an other GLC technique to VLE-measurements for polymer-solvent systems, the so-called head-space gas-chromatography (HSGC). This is practically a combination of static vapor pressure measurement with gas-chromatographic detection. HSGC experiments were carried out with an appa-... 

Steichen RJ. 1976. Modified solution approach for the gas chromatographic determination of residual monomers by head-space analysis. Anal Chem 48 1398-1402. 

Fig. 14.3. Typical capillary gas chromatograph showing locations of the major components. The black hose that highlights the inlet is the transfer fine from a head-space sampler.

The direct gas-chromatographic method is especially suited as an analytical tool for enantiomer analysis when no sample derivatization is required. In the absence of diastereomeric effects between enantiomers ( EE-effect )25, the chiral compound may be investigated in situ, i.e., without isolation and purification using a minute amount of sample, e.g., by head-space analysis with 10 9 g using flame ionization detector (FID) or 1 (F 11 g using selected ion monitoring (GLC-MSSIM). 

Leggett et al (Refs 22 23) used a similar technique, except that their apparatus was static . TNT samples were placed in a 125ml vial equipped with silicone rubber septum cap. The vial was thermostatted and the sample and its vapor were allowed to equilibrate for 2—4 weeks. Vapor was withdrawn from the head-space with a stainless steel syringe and injected into a gas chromatograph. The concn of TNT in the headspace vapor was determined by manual triangulation of the peak, giving peak area/ volume, and dividing by the detector response factor (peak area/mass), as determined by injection of known quantities of TNT dissolved in benzene... 

Involves a sample being vaporized and injected into the head space of the chromatographic column. The sample is transported through the column by the flow of an inert gas (mobile phase). The column itself contains a liquid stationary phase which is adsorbed onto the surface of an inert solid. Retention time with detection techniques (spectrophotometer, mass spectrometry, fluorescence) identifies the compound. 

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