A fiber optode for p-nitrophenol based an covalently bound 9-allylaminoacridine

Using 9-allylaminoacridine synthesized in this laboratory as the fluorescent agent an fiber optode for p-nitrophenol (p-Np) has been prepared. 9-Allyl-aminoacridine has a polymerizable olefin unit and can be copolymerized with hydrophilic monomer 2-hydroxy-propyl methacrylate (HPMA) under UV irradiation. On silanized activated glass surface a 9-allylaminoacridine containing HPMA membrane has been covalently bound forming a stable optode membrane free of leaching problem. The analytical performance characteristics including reversibility, reproducibility, short-term stability and interference have been evaluated. The optode has relatively long lifetime with the spectral response characteristics not changing after one month use. The plot of log(I-0/I - I) versus logarithm of the p-NP solution concentration can piecewise be fitted with the straight line of the form of Stern-Volmer equation, with a detection limit of 9.0 x 10(-8) mol L-1. The relative standard deviation obtained from eight separate determinations for two p-NP concentrations, 1.0 x 10(-5) and 4.0 x 10(-4) mol L-1, are 2.36% and 1.34%, respectively, p-Np can be determined in water samples with satisfactory recoveries.