A simple sample preparation technique using a hollow fiber membrane in conjunction with highrnperformance liquid chromatography has been developed for the extraction and determination ofrns-triazine herbicides and their major metabolites from environmental water and human urinernsamples. Optimum extraction conditions have been evaluated with respect to solvent type,rnacceptor and sample pH, extraction time, shaking speed and salt content as well as humic acidrneffect. The extraction method has been validated for matrices such as reagent water, tap water,rnriver water and human urine samples, indicating that regent water can be selected asrnrepresentative matrix for routine analysis of these environmental water samples and humanrnurine samples. A high level of detection linearity with regression coefficients (r2) ranged fromrn0.994 to 0.999 was obtained for herbicides over a range of analyte concentrations between 50rnand 100 Î¼g/L, using peak area as a response variable. The repeatability and reproducibility ofrnthe method were less than 11 and 17% for concentration of 50 Î¼g/L, respectively. Limits ofrndetection of the method ranged from 0.03 to 1.12 Î¼g/L and the limits of quantification from 0.10rnto 3.73 Î¼g/L, which were low enough to determine all the herbicides residues exceptrndesisopropylatrazine at concentrations below or equal to the maximum residue levels (MRLs)rnspecified by European Union. The method was finally applied to the determination of thernherbicides in tap water, river water and human urine samples and the concentrations found inrnthese samples were always lower than the MRLs except desisopropylatrazine in tap water