Chromatography-mass spectrophotometric techniques for air pollutants: a commentary.

Chromatography is an analytical technique employed for purification and separation of organic and inorganic substances including characterisation and quantitative measurement of compounds (table). Basically there are two types: l. Gas chromatography (GC), 2. Liquid chromatography (LC). Although discovered in 1906 by Tshett, developed in the 1950s as the GC technique where the mobile phase are gases such as helium (He), nitrogen (N 2 ), yet depends on temperature programming and the boiling point of the compound. Quantitative measurement of volatile organic compounds (VOC), polyaromatic hydrocarbons (PAH) and pesticides are controlled by the boiling point (BP) <400°C, being volatile and thermally stable in passing through the glass tubular column capillaries to ensure reliability.