DETERMINATION OF 4-NONYLPHENOL .2. ORTHOGONAL ARRAY DESIGN AS A CHEMOMETRIC METHOD FOR THE SOLID-PHASE MICROEXTRACTION OF 4-NONYLPHENOL IN WATER

Orthogonal array design (OAD) using two-level OA(8)(2(7)) matrix was e mployed for the optimization of solid-phase microextraction (SPME) con ditions for the determination of Lt-nonylphenol (4-NP) in water. The p arameters under consideration for the optimization of SPME conditions include: injector port temperature, initial oven temperature, desorpti on time, and pH. The effect of dissolved humic substances on the extra ction efficiency of SPME for the determination of 4-NP was also invest igated. The method is capable of parts per billion detection limit wit h a %RSD of 6.5%. Thus, the SPME approach is suitable for analytical d etermination of 4-NP in environmental water samples compared to conven tional liquid-liquid extraction (LLE) technique. (C) 1996 John Wiley & Sons, Inc.