Simultaneous Spectrophotometric Determination of Nitrophenol Isomers in Environmental Samples Using First Derivative of the Density Ratio Spectra



A new spectrophotometric method was developed for the simultaneous of ternary mixtures of nitrophenol isomers, without prior separation steps. This method is called the first derivative of the density ratio spectra. All factors affecting on the sensitivity were optimized and the linear dynamic range for determination of nitrophenol isomers was found. The method made use of a derivative of the double-divisor-ratio spectra of optical density. In this case, the linear determination ranges are 1.0-25.0 mg mL-1 for m-nitrophenol, 1.0-25.0 mg mL-1 for o-nitrophenol and 1.0-15.0 mg mL-1 for p-nitrophenol. The RMSEP for m-nitrophenol, o-nitrophenol and p-nitrophenol by proposed method was 0.4907, 0.4779 and 0.2068, respectively. The method developed in this paper was rapid, easy to apply, not expensive and it was suitable for analyzing to overlapping signals of compounds in their mixtures without any chemical pre-treatment and also, the proposed method was satisfactorily applied to the rapid simultaneous determination of m-nitrophenol, o-nitrophenol and p-nitrophenol in synthetic and water samples.


  1. Long H, Zhu YX, Kissinger PT (2003) Liquid chromatography with multi-channel electrochemical detection for the determination of natural phenolic compounds. Chin J Anal Chem 31:631-634.
  2. Wise HE, Fahrenthold PD (1981) Predicting priority pollutants from petrochemical processes. Environ Sci Technol 15:1292-1304.
  3. Guo X, Wang Z, Zhou S (2004) The separation and determination of nitrophenol isomers by high-performance capillary zone electrophoresis. Talanta 64:135-139.
  4. Xuan CS, Wang ZY, Song JL (1998) Spectrophotometric determination of some antibacterial drugs using p-nitrophenol. Anal Lett 31:1185-1195.
  5. Tesarova E, Sykora D, Voznakova Z (1995) GC and HPLC determination of nitrophenol related pesticides. Fresenius Environ Bull 4:609-616.
  6. Yamauchi Y, Ido M, Ohta M, Maeda H (2004) High performance liquid chromatography with an electrochemical detector in the cathodic mode as a tool for the determination of p-nitrophenol and assay of acid phosphatase in urine samples. Chem Pharm Bull 52:552-555.
  7. Wrobel K, Urbina EMC, Romero JM (2000) The determination of 3-nitrophenol and some other aromatic impurities in 4-nitrophenol by reversed phase HPLC with peak suppression diode array detection. J Pharm Bimed Anal 22:295-300.
  8. Zhao T, Hu X, Cheng J, Lu X (1998) Use of calix[4]arene to separate positional isomers in capillary electrophoresis. Anal Chim Acta 358:263-268.
  9. Garcia Montelongo F, Sanchez MJ, Garcia Castro JC, Hardisson A (1991) 2nd and 3rd Order derivative spectrophotometric determination of ascorbic acid in soft drinks. Anal Lett 24:1875-1883.
  10. Garcia CM, Lage-Yusty MA, Simal Lozano J (1990) Second derivative visible spectroscopic determination of iron and manganese in Galician wines. Fresenius J Anal Chem 338:703-706.
  11. Ghasemi J, Niazi A, Ghobadi S (2005) Simultaneous spectrophotomettric determination of benzyl alcohol and diclofenac in pharmaceuticals using methods based on the first derivative of the optical density ratio. Pharmaceutical Chem J 39:51-55.
  12. Dinc E, Onur F (1998) Application of a new spectrophotometric method for the analysis of a ternary mixture containing metamizol and caffeine in tablets. Anal Chim Acta 359:93-106.
  13. Dinc E (1999) The spectrophotometric multicomponent analysis of a ternary mixture of ascorbic acid, acetylsalicylic acid and paracetamol by the double divisor-ratio spectra