Development and validation of a fast and simple HPLC method for the simultaneous determination of aniline and its degradation products in wastewater

In this study, a rapid and simple method based on reversed-phase high performance liquid chromatography (RP-HPLC) using a photodiode array detector (PDA) for the simultaneous analysis of five pollutants including aniline and its degradation products, para-aminophenol, meta-aminophenol, ortho-aminophenol and phenol, was developed. The retention and selectivity of these pollutants were investigated by testing three different columns (C18, C8 and C4) and changing several experimental parameters such as the organic modifier nature and content, buffer concentration, pH value and column temperature. The best chromatographic results were obtained using the C4 column and a mobile phase composed of MeOH/acetate buffer (10 mM, pH 5) (60 : 40, v/v), with lambda = 270 nm and a flow rate of 1 mL min(-1). The influence of the temperature was also investigated in the range of 10-50 degrees C; the results indicated the dependence of the enthalpies of transfer of the analytes on the mobile phase and the nature of the stationary phase, and a good linear correlation of In k vs. 1/T was observed for all the tested columns. The linearity of the method ranged from 2.0 to 60 mu g mL(-1) for all compounds, with correlation coefficients varying from 0.9987 to 0.9999. Recoveries of aniline and its degradation products in water ranged from 87.51% to 101.35% while the relative standard deviations varied between 0.31% and 1.62% (n = 6). The limits of quantification of the method ranged from 0.0778 to 0.2073 mu g mL(-1). The results show that the method we developed is fast, low cost and can meet the requirements for the determination of aniline and its degradation products in waste or natural waters.