Extraction of surfactants out of solid matrices

The extraction behaviour from three different types of solid samples (dried sewage sludge, soil, sediment) was investigated. The samples containing tw o cationic, one anionic and one nonionic surfactant were extracted with met hanol by soxhlet extraction, accelerated solvent extraction (ASE), and by m icrowave assisted extraction. The clean up of the the extracts and their ch romatographic separation into the surfactant classes were carried out on al umina oxide columns. The surfactants were quantitatively determined after s eparation by HPLC either directly (anionic and nonionic surfactants) or aft er post column derivatization (cationic surfactants). The recovery was foun d to be generally 70-100%.