Chemistry Reference
In-Depth Information
10
Green Chromatography
Chi-Yu Lu
Department of Biochemistry, Kaohsiung Medical University, Kaohsiung, Taiwan
Chromatography has been widely used in several fields for a long time. One kind of technique, liquid
chromatography, is a powerful tool for sample separation and purification but organic waste is dramatically
produced at the same time. Green chemistry consists of chemicals and chemical processes designed to
minimize the use and generation of hazardous substances [1]. It is important to respect Green Analytical
Chemistry when green chemistry is developed. Green liquid chromatography is one part of Green Analytical
Chemistry. The major goal of green liquid chromatography is to reduce the production of organic waste in
order to decrease these harmful chemicals and protect our environment.
10.1
Greening liquid chromatography
Greening liquid chromatography (LC) has two main purposes: to reduce the use of organic solvents and
minimize the production of organic waste. How can the production of organic waste under reasonable
analytical time be minimized? Table 10.1 shows four strategies to attain this goal.
Compared with normal-phase LC that uses a lot of organic solvents, reversed-phase LC could attain this
aim. For reversed-phase LC, the composition of the mobile phase is water and water miscible solvents.
Reversed-phase C18, made up of aliphatic alkyl chains, is the most common stationary phase used in several
fields. Except for very hydrophobic compounds, this kind of strategy could reduce the use of organic solvents
because one of the eluents is water.
For very aliphatic analytes, C8 or C4 may be a suitable alternative for the stationary phase. Using more
hydrophobic stationary phase to separate aliphatic compounds will increase the usage of organic solvents in
order to elute the analytes in a suitable time. Under an acceptable range of separation and selectivity, the
change of stationary phase from C18 to C8 or C4 could shorten retention time and then reduce the use of
