title: Comprehensive analytical methodology to determine hydrocarbons in marine waters using extraction disks coupled to glass fiber filters and compound-specific isotope analyses.
abstract: Solid-phase extraction of both aliphatic (AHs) and aromatic polycyclic hydrocarbons (PAHs) from seawater samples was evaluated using a GFF filter stacked upon an octadecyl bonded silica (C18) disk. Stable-isotope measurements were developed on hydrocarbons extracted from both GFF and C18-disks in order to characterize the source of hydrocarbons. A clear partition of hydrocarbon compounds between the dissolved and the particulate phase was highlighted. PAHs showed a higher affinity with the dissolved phase (recoveries efficiency of 48-71%) whereas AHs presented strong affinity with the particulate phase (up to 76% of extraction efficiency). Medium volumes of seawater samples were tested and no breakthrough was observed for a 5L sample. Isotopic fractionation was investigated within all analytical steps but none was evidenced. This method has been applied to harbor seawater samples and very low AH and PAH concentrations were achieved. Due to the low concentration levels of hydrocarbons in the samples, the source of hydrocarbons was determined by molecular indices rather than isotopic measurements and a pyrolytic origin was evidenced. The aliphatic profile also revealed the presence of long-chain linear alkylbenzenes (LABs). The methodology presented here would better fit to polluted coastal environments affected by recent oil spills.
authors.affiliation: International Atomic Energy Agency - Environment Laboratories, 4, quai Antoine 1(er), MC 98000, Monaco; Institut de Chimie de Nice-PCRE (Processus Chimiques et Radiochimiques dans l'Environnement), UMR 7272 CNRS, Université de Nice Sophia-Antipolis, Faculté des Sciences, Parc Valrose Nice 06108, France. Electronic address: eva.ternon@unice.fr.
authors.forename: Eva
authors.initials: E
authors.lastname: Ternon
authors.affiliation: International Atomic Energy Agency - Environment Laboratories, 4, quai Antoine 1(er), MC 98000, Monaco. Electronic address: I.tolosa@iaea.org.
authors.forename: Imma
authors.initials: I
authors.lastname: Tolosa
mesh_terms: D002623:Chemistry Techniques, Analytical / Q000295:instrumentation / Q000379:methods*; D005898:Glass / Q000737:chemistry; D006838:Hydrocarbons / Q000032:analysis*; D007554:Isotopes / Q000032:analysis; D012623:Seawater / Q000737:chemistry*; D052616:Solid Phase Extraction; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D006838:Hydrocarbons; D007554:Isotopes; D014874:Water Pollutants, Chemical; C009753:fiberglass
keywords: C18-disk; Dissolved phase; Hydrocarbons; Isotope fingerprinting; Particulate phase; Seawater