title: Co-extraction and simultaneous determination of multi-class hydrophobic organic contaminants in marine sediments and biota using GC-EI-MS/MS and LC-ESI-MS/MS.
abstract: A multi-residue analytical method was developed involving co-extraction and simultaneous determination of 89 hydrophobic organic contaminants (HOCs) in marine sediments and biota using gas chromatography-electron ionization-triple quadrupole mass spectrometry (GC-EI-MS/MS) and liquid chromatography-electrospray ionization-triple quadrupole mass spectrometry (LC-ESI-MS/MS). Target analytes include polychlorinated biphenyls (PCBs), pesticides, chlorobenzenes, brominated and chlorinated flame retardants, nitro-aromatic and polycyclic musks, triclosan and methyl triclosan. Spike-recovery experiments showed relative recoveries of analytes were generally between 70% and 130%. Analyses of a sediment standard reference material (SRM 1944) demonstrated recoveries between 80% and 120% for certified concentrations of individual PCBs and pesticides. Method detection limits of individual compounds ranged from 0.1 to 57.1 pg/g dw for sediments and 0.1 to 22.8 pg/g ww for biota. A field survey of sediments and biota from Singapore's marine environment demonstrated the occurrence of polycyclic and nitro-aromatic musks (galaxolide, tonalide, musk ketone, etc.), halogenated flame retardants (syn- and anti-dechlorane plus (DP), α, β and γ-hexabromocyclododecane (HBCD), tetrabromobisphenol A (TBBPA), etc.), as well as triclosan and methyl triclosan. Galaxolide exhibited relatively high concentrations, with highest levels in polychaete worms (161.7±72.5 ng/g ww) and clams (546.8±220.3 ng/g ww) from mangroves. Triclosan and methyl triclosan levels were highly correlated in sediments (r(2)=0.9752), while syn- and anti-DP were strongly correlated in biota (r(2)=0.9279). anti-DP/syn-DP stereoisomer ratios were typically >1 and ranged between 0.94 and 29.2 in sediments and biota samples. γ-HBCD exhibited the highest concentrations among HBCD isomers in sediments. Conversely, α-HBCD was the dominant HBCD isomer in biota.
authors.affiliation: Department of Civil and Environmental Engineering, National University of Singapore, Singapore.
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Civil and Environmental Engineering, National University of Singapore, Singapore.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Bayen
authors.affiliation: Department of Civil and Environmental Engineering, National University of Singapore, Singapore. Electronic address: bckelly@nus.edu.sg.
authors.forename: Barry C
authors.initials: BC
authors.lastname: Kelly
mesh_terms: D058448:Biota; D005591:Chemical Fractionation / Q000379:methods*; D002623:Chemistry Techniques, Analytical / Q000379:methods* / Q000592:standards; D002853:Chromatography, Liquid; D008401:Gas Chromatography-Mass Spectrometry; D019015:Geologic Sediments / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D009792:Oceans and Seas; D009930:Organic Chemicals / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification*; D012015:Reference Standards; D015203:Reproducibility of Results; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification
chemical_list: D009930:Organic Chemicals; D014874:Water Pollutants, Chemical
keywords: Emerging organic contaminants; GC-EI-MS/MS; LC-ESI-MS/MS; Legacy POPs; Marine biota; Multi-residue analysis; Sediments