title: Selective pressurized liquid extraction for multi-residue analysis of organochlorine pesticides in soil.
abstract: A selective pressurized liquid extraction (SPLE) procedure capable of performing simultaneous extraction and clean-up has been demonstrated for multi-residue analysis of organochlorine pesticides (OCPs) in soil. The final method was performed at 100 degrees C for 3 x 10 min using acetone/n-heptane (1:1, v/v). Florisil was placed inside the extraction cell downstream the sample to remove interfering compounds. Extraction of two soil samples by SPLE gave a recovery which was over 80% for beta-endosulfan, endosulfan sulfate, p,p'-DDT and p,p'-DDE compared to PLE with off-line clean-up. The same trend was observed when applying the SPLE method to a certified reference soil sample (CRM 811-050) containing 13 OCPs, where the SPLE method gave 80-90% recovery vis-à-vis the PLE method with off-line clean-up. Feasibility of the SPLE method was further demonstrated by applying it to five real soil samples collected in Ethiopia.
authors.affiliation: Department of Chemistry, Addis Ababa University, Addis Ababa, Ethiopia.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Hussen
authors.forename: Rikard
authors.initials: R
authors.lastname: Westbom
authors.forename: Negussie
authors.initials: N
authors.lastname: Megersa
authors.forename: Lennart
authors.initials: L
authors.lastname: Mathiasson
authors.forename: Erland
authors.initials: E
authors.lastname: Björklund
mesh_terms: D000096:Acetone; D053000:Analytic Sample Preparation Methods / Q000379:methods*; D004784:Environmental Monitoring / Q000379:methods; D006536:Heptanes; D006843:Hydrocarbons, Chlorinated / Q000032:analysis*; D010573:Pesticide Residues / Q000032:analysis*; D011312:Pressure; D012989:Soil Pollutants / Q000032:analysis*; D012997:Solvents; D014465:Ultrasonics
chemical_list: D006536:Heptanes; D006843:Hydrocarbons, Chlorinated; D010573:Pesticide Residues; D012989:Soil Pollutants; D012997:Solvents; D000096:Acetone; C028618:n-heptane