Sulfonylureas natural waters

Hydrolysis appears to be a very significant pathway for the fate of sulfonylurea pesticides in sediments and natural waters. Although these chemicals often have many different functional groups, the principal cleavage occurs at the sulfonylurea bridge. The reaction is highly pH dependent (Equation (17)) ... 

Nilve G, Knutsson M, and Jdnsson JA. Liquid chromatographic determination of sulfonylurea herbicides in natural waters after automated sample pretreatment using supported liquid membranes. J. Chromatogr. A 1994 668 75-82. 

Immunoaffinity extraction is a technique often adopted in clinical chemistry. Immu-noaffinity supports contained polyclonal antibodies covalently immobilized on sephar-ose, agarose, or silica supports. Two different kinds of supports, crushed sol-gel monoliths and sol-gel-coated highly porous silica particles, were applied to the extraction of 16 sulfonylureas in food and natural water followed by high-performance liquid chromatography-ultraviolet/diode-array detection (LC-UV/DAD) [32]. 

Thompson, D.G. and MacDonald, L.M., Trace-level quantitation of sulfonylurea herbicides in natural water, J. Assoc. Off. Anal. Chem., 75,1084,1992. 

Solvent extraction is usually carried out in a separatory furmel, which is vigorously shaken to increase the contact area between the two liquids. This operation enhances the extraction rate and )deld. The LLE technique has been proposed for isolating phenyl-ureas and sulfonylrueas [14-19] from water samples. In all these methods, dichloro-methane has been used as the extracting solvent. For efficiently extracting sulfonylureas, which are weakly acidic in nature, the pH of the water sample was adjusted in advance to 3. EBDC fungicide anions are extracted as an ion pair with tetrabutylammonium into chloroform-hexane [20], while diethyl ether-petroleum ether solution [21] is used for extracting triazines and other herbicides. 

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