THE EFFECT OF SURFACTANT AND POLYCYCLIC AROMATIC HYDROCARBON INTERFERENCES ON THE SPE AND HPLC DETERMINATION OF NITROGEN-CONTAINING PESTICIDES

The authors extracted twelve pesticides - carbaryl, carbendazim, carbo furan, dietofencarb, dioxacarb, fenothiocarb, iprodione, methomyl, mol inate, oxamyl, thiobencarb and thiophanate-methyl - from distilled wat er using 0.5-g C8 solid-phase extraction columns and reversed-phase hi gh performance liquid chromatography (HPLC) with UV-absorbance detecti on. Their study investigated interferences caused by the presence of c ommon contaminants such as surfactants and polycyclic aromatic hydroca rbons. They found that the presence of cetyltrimethylammonium bromide and sodium tetradecyl sulfate diminished the molinate and thiophanate- methyl recoveries and that the presence of acenaphthene, fluorene, phe nanthrene, and anthracene interfered with HPLC-UV determination of ipr odione and thiobencarb, but lighter and heavier polycyclic aromatic hy drocarbons had no effect.