Comparison of the static, dynamic and static-dynamic pressurised liquid extraction modes for the removal of nitrated polycyclic aromatic hydrocarbons from soil with on-line filtration-preconcentration.
The three operational modes of pressurised liquid extraction (PLE) (namely, static, dynamic and static-dynamic) have been applied for the extraction of nitrated polycyclic aromatic hydrocarbons from both spiked and natural contaminated soils. A comparison of the three modes in terms of experimental set-up used, extraction time needed for total removal of the analytes and precision has been carried out. The use of a flow-injection manifold as interface between every pressurised extractor and a filtration-preconcentration system has allowed the partial automation of the proposed approaches. Efficiencies close to 100% have been provided by the three operational modes. However, the static-dynamic mode has been proved as the most suitable alternative providing the shortest extraction time (25 min) versus the static (30 min) and the dynamic (50-70 min) modes. Gas chromatography with MS-MS ion preparation mode has been used providing both high selectivity (no interferences were observed) and sensitivity (detection limits of low pg). The comparison of the proposed approaches with the reference method 3540 of the US Environmental Protection Agency (EPA) has shown that both methods provide similar efficiencies with an important shortening in the extraction time (25-70 min by PLE versus 24 h by the EPA method). The use of water as leaching agent has avoided the use of organic solvents providing an environmentally friendly method.
Luque-García
J L
JL
Department of Analytical Chemistry, Marie Curie Building, Annex, Campus of Rabanales, University of Córdoba, E-14071 Córdoba, Spain. q52lugaj@uco.es
Luque de Castro
M D
MD
D005374:Filtration / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry; D009566:Nitrates / Q000737:chemistry*; D011083:Polycyclic Compounds / Q000737:chemistry / Q000302:isolation & purification*; D011312:Pressure; D012015:Reference Standards; D012680:Sensitivity and Specificity; D012989:Soil Pollutants / Q000032:analysis / Q000302:isolation & purification*
D009566:Nitrates; D011083:Polycyclic Compounds; D012989:Soil Pollutants