Purge-and-trap extraction and GC-FID determination of phenols from soil sam
ples has been optimised making use of the simplex method implemented in the
MultiSimplex program for four phenols (2-chlorophenol, 2-methylphenol, 2-n
itrophenol and 2,4-dichlorophenol). The experimental variables studied were
the sample heating time and temperature, the purge time and the concentrat
ion of sodium chloride. Once the optimum conditions were established the re
producibility of the extraction yield was tested by means of repeated analy
sis on different samples. These results were compared with previously optim
ised microwave-assisted extraction and Soxhlet extraction. (C) 1999 Elsevie
r Science B.V. All rights reserved.