C18, PSA, And GCB QuEchERS Dispersive Absorbents
Except for the extraction process, another significant part of QuEchERS is the purification. The most important product applied in this process is QuEchERS absorbents. It is mainly used for the removal of impurities in the sample. There are three common absorbents widely sold in the market, including C18, PSA, and GCB QuEchERS dispersive absorbents.
C18 QuEchERS Dispersive Absorbents
The C18 absorbent is highly suitable for the adsorption of lipid compounds, such as olive oil. It is mainly applied in the food industry. In most cases, it will be used with PSA absorbent together in order to get a better purification effect without any loss or damage to the sample itself.
PSA QuEchERS Dispersive Absorbents
The PSA absorbent is often used for the pretreatment of samples in pesticide residue analysis, especially for the general fruit with no special requirements. It is mainly used adsorb and remove the organic acids, pigments, metal ions and phenols in the extract solutions.
GCB QuEchERS Dispersive Absorbents
The GCB (Graphite carbon black) absorbent is a carbon material produced by heating carbon black to about 2700 °C under the protection of inert gas (usually argon). It could adsorb non-polar and weakly polar compounds. Also, it can adsorb some polar compounds or used as anion exchangers. It is greatly used for the determination of fruits and vegetables by adsorbing the chlorophyll and carotenoids effectively.