A method for qualitative and quantitative determination of paraphenylenediamine in biological fluids (blood, urine and gastric content) was developed. This analytical procedure involves deproteneisation or hydrolysis, liquid-liquid extraction, derivatization with TFA followed by GC-MS iontrap analysis. Benzidine was the internal standard used for quantification and the extraction recovery test was about 85%. The detection limit of paraphenylenediamine was determined at 0.1 pg (S/N=10).