objective(s): dispersive liquid-liquid microextraction coupled with gas chromatography (gc)-flame ionization detector was developed for the determination of valproic acid (vpa) in human plasma. materials and methods: using a syringe, a mixture of suitable extraction solvent (40 µl chloroform) and disperser (1 ml acetone) was quickly added to 10 ml of diluted plasma sample containing vpa (ph, 1.0...

in this study, simple and efficient ultrasound-assisted emulsification microextraction (usaeme) combined with gas chromatography-flame ionization detector (gc-fid) was developed for the preconcentration and determination of carbamazepine in biological samples. in this method, the fine droplets of 1-octanol were formed and dispersed in the sample with the help of ultrasonic waves, which accelera...

An analytical method, based on separation with gas chromatography (GC) and detection with optical fiber (OF), was used for the separation, detection and quantification of benzene, toluene, ethylbenzene, p-xylene, m-xylene and o-xylene. The use of OF as a detector is based on the variations of the reflected optical power detected when the aromatic compounds eluted from the GC column are sorbed i...

A simplified method for following the urinary excretion of estriol, pregnanediol, and pregnanoloneduring the course of pregnancy is presented. The procedure has been used successfully in a large hospital laboratory. An important advantage is that the estrogen and progesterone metabolites are measured simultaneously, and separate extraction and gas-liquid chromatographyis not required. The urine...

in the present study the volatile organic compounds of e. azerbaijanica rech.f. were identified. phytochemical assessment of meoh extract of aerial parts of this plant was also performed and its free radical scavenging properties was evaluated. the essential oil of the air-dried aerial parts was obtained by hydro-distillation using a clevenger type apparatus. the oil was then analyzed by gas ch...

Prepared standards of halothane in oxygen were analysed using a Pye Series 104 gas chromatograph equipped with a heated head flame ionization detector and gas sampling valve. The adoption of a positive jet voltage expanded the linear dynamic range of the detector to cover the 0.5-9.0% by volume range, provided that a small (0.5-ml) sample loop was used.

A commercial flame ionization detector was converted to a gas chromatographic detector selective for silicon-containing compounds by simply interchanging the oxygen and hydrogen inlets so that the flame burned in a hydrogen atmosphere. The optimal configuration of various detector geometries was found to be a narrow cylindrical tube with the collector electrode positioned more than 10 cm from t...

A novel gas chromatography detector is described that uses acoustic signals from a partly premixed hydrogen-air flame burning on top of a capillary. The device, referred to as the acoustic flame detector (AFD), is based on the measurement of the frequency of acoustic transients generated at the burner under a range of operating conditions. The presence of trace amounts of analyte in the flame w...

Background: Nanotechnology is a new approach that has been lionized in recent years. One of its applications is its consumption as an absorbent. In this study, the single-wall carbon nanotubes (SWCNTs) were used as an absorbent for sampling benzene in the air. Materials and Methods: For this study, SWCNTs manufactured by Iran and SKC’s activated charcoal were used for sampling benzene vapors....