Trace gas Trace gas The most abundant gases in the atmosphere are nitrogen (78.1%), oxygen (20.9%), and argon (0.934%). Combined, oxygen, argon, and nitrogen make up 99.934% of the gases in the atmosphere (not including water vapor). The other gases that are not part of the 99.934% of the atmosphere are called trace gases. The abundance of a trace gas can range from a few parts per trillion (ppt) by volume to several hundred parts per million by volume (ppmv). When a trace gas is added into the atmosphere, that process is called a "source". There are two possible types of sources
Headspace gas chromatography for dissolved gas measurement Headspace gas chromatography for dissolved gas measurement Headspace gas chromatography uses headspace gas injected directly onto a gas chromatographic column. Chemists often use the phrase "standard temperature and pressure or STP" to convey that they are working at a temperature of 25 °C and one atmosphere of pressure. There are three states of matter under these conditions: solids, liquids, and gases. Although all three are distinct states both solids and gases can dissolve (or disperse) in liquids. The most commonly occurring liquid in the biosphere is water. All components of the atmosphere are capable of dissolving in water to some