A new method for the determination of 2,4-dinitrophenol in mixtures by pH changed gradually spectral rank annihilation factor analysis has been developed.In the method described here,the pH of the Britton-Robinson buffer solution containing 2,4-dinitrophenol was changed gradually by adding sodium hydroxide solution into the solution.In this process,the spectrum of the solutin at different pH has been recorded and then the acidity-absorbance spectra ma...