GAS-CHROMATOGRAPHIC DETERMINATION OF NITROPHENOLS AFTER DERIVATIZATION WITH DIAZOMETHANE

A method is described to determine nitrophenols and two herbicides (Bromoxynil, Ioxynil) in precipitation, with GC-PND and GC-MS. First, the micropollutants were extracted by a mixture of pentane and ether (1/1), concentrated by rotary evaporator, then methylated by diazomethane. The extraction and reaction yields were measured. The resulting recoveries were between 75 and 100% for the mononitrophenols and about 70% for methylnitrophenols. The detection limits were about 0.25-mu-g/l for most substances.