SAMPLE PREPARATION FOR EFFECTIVE DETERMINATION OF POLYCHLORINATED DIBENZODIOXINS FROM LEACHATES

Abstract

Four pretreatment methods, including LLE-HPLC, LLE- DMSO, SPE-HPLC and SPE-DMSO are compared for the effective determination of polychlorinated dibenzodioxins (PCDDs) from a leachate sample. For the LLE-HPLC method, liquid–liquid extraction (LLE) with dichloromethane is used for the initial extraction of the analytes from leachate. For the elimination of interferences coextracted from leachate, acid treatment, followed by high performance liquid chromatographic (HPLC) column clean-up, is performed. For the LLE-DMSO method, LLE, acid treatment and extraction with dimethyl sulfoxide (DMSO) are accomplished, consecutively. For the SPE-HPLC method, solid-phase extraction of disk-type with toluene–ethanol mixture (3:7, v/v), acid treatment, and HPLC column clean-up are performed, consecutively. For the SPE-DMSO method, SPE with DMSO and acid treatment are performed, consecutively. After each of these methods, column clean-ups including multilayer silica gel and alumina are performed, sequentially. The final extract is analyzed by HPLC-UV. For SPE, a toluene–ethanol mixture, conventional solvent is used for the extraction of PCDDs from SPE of disk-type. However, the use of DMSO with a selective interaction with aromatic compounds shows higher efficiencies when considering time, solvent usage, and removal of interferences.

ACKNOWLEDGMENT

The authors wish to acknowledge the financial support of the Korea Research Foundation made in the program year of 1999.