Flumetsulam … is a member of the triazolopyrimidine sulfonanilide family of herbicides. It is used for pre or post-emergence broadleaf weed control in wheat, corn, barley and soybean. It has low toxicity and is readily degradable. A HPLC-UV method for the analysis of flumetsulam with the use of a surrogate and internal standard was developed and validated for soybean. The surrogate and internal standards are diclosulam and benzoic acid respectively. A LC-ESI-MS/MS confirmation method in the positive ion mode was also developed for flumetsulam. In the solvent-solvent extraction method, flumetsulam was extracted from the soybean with MeOH and the extract partitioned with a hexane:MTBE mixture (which was discarded). In the solid phase extraction and clean up method, C-18, SAX and SCX cartridges were used. Flumetsulam was extracted from the soybean as for the solvent-solvent extraction method. The solvent-solvent extraction method was used for flumetsulam determination at fortification levels of 10, 20, 50 and 100 ng -g soybean -1. The method has average absolute recoveries of 80% (range 72 to 90%). The absolute precision of recovery is about 16% and the detection limit is 4.8 ng g-1.The solid phase extraction method was used for flumetsulam determination at fortification levels of 20, 50, and 100 ng (ng soybean )-1. The precision of recovery is about 11%. The detection limit is 7.2 ng g-1. The MRL for flumetsulam recommended by the Australian Pesticides and Veterinary Medicines Authority is 50 ng g-1 for pulses. / Doctor of Philosophy (PhD)