Ad
related to: headspace gas chromatography alcohol concentration
Search results
Results From The WOW.Com Content Network
The method uses headspace gas injected into a gas chromatographic column (GC) to determine the original concentration in a water sample. [ 9 ] A sample of water is collected in the field in a vial without headspace and capped with a Teflon septum or crimp top to minimize the escape of volatile gases.
Gas chromatography (GC) is a common type of chromatography used in analytical chemistry for separating and analyzing compounds that can be vaporized without decomposition. Typical uses of GC include testing the purity of a particular substance, or separating the different components of a mixture. [ 1 ]
The target analytes are extracted by mixing the sample with water and purge with inert gas (e.g. Nitrogen gas) into an airtight chamber, this is known as purging or sparging. The volatile compounds move into the headspace above the water and are drawn along a pressure gradient (caused by the introduction of the purge gas) out of the chamber ...
A variety of methods exist for determining blood-alcohol concentration in a blood sample. [19] Forensic laboratories typically use headspace-gas chromatography combined with mass spectrometry or flame ionization detection, [20] as this method is accurate and efficient. [19]
English: Schematic drawing of the headspace analysis in gas chromatography. After thermal equilibration, a sample is taken out of the headspace and the analytical compounds are seperated and identified on the GC column. Main advantage: Even with complex sample matrices (e.g. blood, honey), the GC column is not contaminated with sample components.
In gas chromatography-mass spectrometry (GC-MS), deuterated compounds with similar structures to the analyte commonly act as effective internal standards. [8] However, there are non-deuterated internal standards such as norleucine , which is popular in the analysis of amino acids because it can be separated from accompanying peaks.
Headspace technology is a technique developed in the 1980s to elucidate the odor compounds present in the air surrounding various objects. Usually the objects of interest are odoriferous objects such as plants, flowers and foods. [ 1 ]
The concentration needed to cause this effect is seen to change as the amount of non-volatile matrix changes. So concentration of solid analyte needs to be considered in the preparation of the solution for analysis so that signal from "hidden" analyte is not missed. [17] To choose the matrix for each solid analyte, three criteria must be ...