Simultaneous spectrophotometric determination of nitroaniline isomers after dispersive liquid-liquid microextraction by

A new method for simultaneous spectrophotometric determination of nitroaniline isomers is developed by dispersive liquid-liquid microextraction (DLLME) preconcentration[1]and chemometrics methods[2]. In the proposed method, dicholoromethaneand asetonitrileare selected as extraction and dispersive solvent. The optimization strategy is carried out by using two level full factorial designs. Results of the two level full factorial design (24) based on an analysis of variance demonstrated that the pH, ionic strength, amount of dispersive and extraction solvents are statistically significant. Optimal condition for three variables: pH, ionic strength, amount of dispersive and extraction solvents are obtained by using Box-Behnken design. Under the optimum conditions, the calibration graphs are linear in the range of 0.05-15.0, 0.03- 14.0 and 0.04-15.0 g mL-1with detection limit of 0.016, 0.011 and 0.15 g mL- 1(3 B/slope) and the enrichment factor of this method for uranium reached at 150. The method is successfully applied to the determination of trace amount of nitroaniline isomers in different water samples. DLLME [3] coupled with orthogonal signal correction-partial least squares (OSC-PLS) algorithm for data processing for determination of uranium in synthesis and real samples. DLLME-OSC-PLS method was presented for the first time in this study. The root mean squares error of prediction for nitroaniline isomersdetermination using PLS and OSC-PLS models were 0.651, 0.542, 0.712and 0.103, 0.098, 0.127, respectively. This procedure allows the determination of nitroaniline isomerssynthesis and real samples such as waste water with good reliability of the determination.