Application of pressurized liquid extraction followed by gas chromatography-mass spectrometry to determine 4-nonylphenols in sediments

A time- and solvent-saving method, pressurized liquid extraction (PLE), to extract 4-nonylphenol (4-NP) in sediment was developed. The effects of vari ous operational parameters (i.e., temperature, pressure, etc.) for the quan titative extraction of 4-NP by PLE were investigated. The analytes were the n identified and quantitated by a large-volume injection GC-MS technique. T he 4-NP can be completely extracted by methanol at 100 degrees C and 100 at m combined with 15 min static and then 10 min dynamic extraction steps (1 a tm=101 325 Pa). Recovery of 4-NP in spiked blank kaolin samples was 98% wit h 5% RSD. The degrees of recovery of 4-NP in the spiked sediment samples fr om a reservoir and a polluted river were 111% with 4% RSD and 106% with 5% RSD, respectively. The perfect applicability of PLE for 4-NP was determined after testing it with spiked and aged samples. The extraction efficiency o f the PLE was compared with conventional Soxhlet and bath ultrasonication e xtraction methods using the spiked sediment samples. (C) 2000 Elsevier Scie nce BN. All rights reserved.