The Extraction of Liquid Samples

T able 5.5 The recovery factors of some organochlorine and organophosphorous pesticides in some solvents 

Various workers have used the LLE approach for the extraction and purification of chiral pollutants of musks in river water [62], PCBs in ringed seals [63], HCH in marine water [64], bromocyclen in surface and waste waters and fish [65], and chlordane in salmons, seals and penguins [66], 

The handling of the solvents is hazardous from the health viewpoint. Also, in LLE emulsion formation is another problem in the extraction of the more polar pollutants such as phenoxy acids herbicides and their metabolites [68]. 

The extraction of polar pesticides using nonpolar (Cig and Cg) stationary phases is very difficult and, therefore, polar pesticides are extracted successfully on graphitized carbon black (GCB). The porous character of GCB makes it faster in extraction, without any pH adjustment of the environmental water samples. Many workers have recommended styrene divinyl benzene copolymer as the universal SPE system for the extraction of pesticides that are even moderately polar in nature [89-92]. Ion exchangers have also been used for the extraction of semi-polar or polar pesticides [93, 94], but their range of utility is low due to their low capacity (the capacity is decreased by the ions in the water samples) and their inability to extract pesticides that have similar acidic-basic moieties, which 

Glass column (exchangeable), id 45 mm Glass fibre filter sheet Sorbent (height 5 mm) 

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