title: Microextraction by packed sorbent coupled with gas chromatography-mass spectrometry: a comparison between "draw-eject" and "extract-discard" methods under equilibrium conditions for the determination of polycyclic aromatic hydrocarbons in water.
abstract: In this work, two different extraction procedures for the analysis of different polycyclic aromatic hydrocarbons (PAHs) in water by microextraction by packed sorbent (MEPS) have been compared in terms of sensitivity, reliability and time of analysis. The first method, called "draw-eject", consists of a sequence of cycles of aspirations and injections in the same vial; the second one, called "extract-discard", consists of a similar cycle sequence, but the aspired sample in this case is discarded into waste. The relevant partition equilibriums and extraction rates have been calculated by multivariate regression from the data obtained after MEPS gas chromatography-mass spectrometry (MEPS-GC-MS) analysis of 16 PAHs from water samples. Partitioning parameters for a priori prediction of solute sorption equilibrium, recoveries and preconcentration effects in aqueous and solvent systems have been calculated and compared for the two extraction procedures. Finally, real samples from sea, agricultural irrigation wells, streams and tap water were analyzed. Detection (S/N≥3) and quantification (S/N≥10) limits were calculated for the extraction processes. Under the experimental conditions used for the "draw-eject" procedure, these values were in the range 0.5-2 ng L(-1) and 1.6-6.2 ng L(-1), while for the "extract-discard" procedure they ranged from 0.2 to 0.8 ng L(-1) and from 0.8 to 2.0 ng L(-1), respectively.
authors.affiliation: SAFE - Department of Science of Agriculture, Food and Environment, University of Foggia, via Napoli 25, I-71100 Foggia, Italy. Electronic address: maurizio.quinto@unifg.it.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Quinto
authors.affiliation: SAFE - Department of Science of Agriculture, Food and Environment, University of Foggia, via Napoli 25, I-71100 Foggia, Italy.
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Spadaccino
authors.affiliation: SAFE - Department of Science of Agriculture, Food and Environment, University of Foggia, via Napoli 25, I-71100 Foggia, Italy.
authors.forename: Donatella
authors.initials: D
authors.lastname: Nardiello
authors.affiliation: SAFE - Department of Science of Agriculture, Food and Environment, University of Foggia, via Napoli 25, I-71100 Foggia, Italy.
authors.forename: Carmen
authors.initials: C
authors.lastname: Palermo
authors.affiliation: Department of Mathematics, University of Bari, via Orabona 4, I-70125 Bari, Italy.
authors.forename: Pierluigi
authors.initials: P
authors.lastname: Amodio
authors.affiliation: Center of Co-Innovation for Natural Resources of Changbai Mountain & Health Industry, Yanbian University, China.
authors.forename: Donghao
authors.initials: D
authors.lastname: Li
authors.affiliation: SAFE - Department of Science of Agriculture, Food and Environment, University of Foggia, via Napoli 25, I-71100 Foggia, Italy.
authors.forename: Diego
authors.initials: D
authors.lastname: Centonze
mesh_terms: D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D057230:Limit of Detection; D059627:Liquid Phase Microextraction / Q000379:methods*; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis*; D015203:Reproducibility of Results; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D011084:Polycyclic Aromatic Hydrocarbons; D014874:Water Pollutants, Chemical; D014867:Water
keywords: Gas chromatography; Mass spectrometry; Mathematical model; Microextraction by packed sorbent; Polycyclic aromatic hydrocarbons; Water analysis