DETERMINATION OF NITROPHENOL PESTICIDES I N MINERAL-WATER AND TAP WATER BY HPLC WITH ULTRAVIOLET AND AMPEROMETRIC DETECTION

A simultaneous analytical method was developed for 9 nitrophenol pesti cides and 2 aromatic nitro pesticides in drinking water by HPLC. The a nalytical HPLC was run on a Wakosil II 3C18AR column (4.6 mm i.d.x15 c m) with a gradient formed from A: 0.1M monochloroacetic acid (pH 2.5)- MeCN-0.01M sodium butanesulfonic acid (10:30:60) and B: 0.1M monochlor oacetic acid (pH 2.5)-MeCN(10:90), UV detection at 280 nm and amperome tric detection (AMD) with a glassy-carbon electrode (+1.2 V). A drinki ng water sample was adjusted to pH 4 with 0.1M hydrochloric acid and p urified on a Sep-pak Plus PS-2 cartridge. The cartridge was washed wit h water, and retained substances were eluted with MeCN. The eluate was concentrated under an Nz stream and was analyzed by HPLC. Recoveries for pesticides spiked into drinking water were 58.0 similar to 98.6% a t the level of 20 mu/L. The detection limits of these pesticides in wa ter are 1 mu g/l.