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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 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. It is beneficial to store the bottles upside ...
For the analysis of volatile compounds, a purge and trap (P&T) concentrator system may be used to introduce samples. 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.
A flame test is relatively quick test for the presence of some elements in a sample. The technique is archaic and of questionable reliability, but once was a component of qualitative inorganic analysis .
If the gas is flammable, the mixture ignites. [1] This test is most commonly used to identify hydrogen, which results with a distinctive 'squeaky pop' sound. [2] Hydrogen is easily ignited and used to definitively conclude what the gas actually is. [3] Further analytical chemistry techniques can clarify the identity of the gas in question.
Gas chromatography is based on a partition equilibrium of analyte between a solid or viscous liquid stationary phase (often a liquid silicone-based material) and a mobile gas (most often helium). The stationary phase is adhered to the inside of a small-diameter (commonly 0.53 – 0.18mm inside diameter) glass or fused-silica tube (a capillary ...
In chemical analysis, matrix refers to the components of a sample other than the analyte [1] of interest. The matrix can have a considerable effect on the way the analysis is conducted and the quality of the results are obtained; such effects are called matrix effects. [2]
The molar volume of gases around STP and at atmospheric pressure can be calculated with an accuracy that is usually sufficient by using the ideal gas law. The molar volume of any ideal gas may be calculated at various standard reference conditions as shown below: V m = 8.3145 × 273.15 / 101.325 = 22.414 dm 3 /mol at 0 °C and 101.325 kPa