Application of an on-line liquid chromatographic system for the determination of polar herbicides in drinking water within a routine laboratory.

A previously developed on-line automated system for the analysis of polar herbicides in raw and drinking water, was further optimised for use within a routine environmental monitoring laboratory. One-hundred-ml portions of sample were extracted onto interchangeable, PLRP-S packed cartridges, prior to desorption by the mobile phase of an HPLC system. Determination of triazine and phenylurea herbicides was achieved by UV diode array detection, with detection limits ranging between 0.002 and 0.012 microgram l-1. Precision, in HPLC grade water, ranged from 3.1 to 9.7% R.S.D. at the 0.090 microgram l-1 level, as determined at those wavelengths selected for routine analysis. Confirmation of positive results was achieved by library searching of UV spectra. The system was found to be robust for routine analysis, with a sample throughput of ten samples per day.