Isomer-Specific Determination of 4-Nonylphenols Using Comprehensive Two-Dimensional Gas Chromatography/Time-of-Flight Mass Spectrometry

Abstract

Technical nonylphenol (tNP), used for industrial production of nonylphenol polyethoxylate surfactants, is a complex mixture of C(3-10)-phenols. The major components, 4-nonylphenols, are weak endocrine disruptors whose estrogenicities vary according to the structure of the branched nonyl group. Thus, accurate risk assessment requires isomer-specific determination of 4-NPs. Comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry (GC x GC/ToFMS) was used to characterize tNP samples obtained from seven commercial suppliers. Under optimal chromatographic conditions, 153-204 alkylphenol peaks, 59-66 of which were identified as 4-NPs, were detected. The 4-NPs comprised approximately 86-94% of tNP, with 2-NPs and decylphenols making up approximately 2-9% and approximately 2-5%, respectively. The tNP products were analyzed for eight synthetic 4-NP isomers, and results were compared with published data based on GC/MS analysis. Significant differences were found among the products and between two samples from a single supplier. The enhanced resolution of GC x GC coupled with fast mass spectral data acquisition by ToFMS facilitated identification of all major 4-NP isomers and a number of previously unrecognized components. Analysis of tNP altered by the bacterium, Sphingobium xenophagum Bayram, revealed several persistent 4-NPs whose structures and estrogenicities are presently unknown. The potential of this technology for isomer-specific determination of 4-NP isomers in environmental matrices is demonstrated using samples of wastewater-contaminated groundwater and municipal wastewater.

Gas Chromatography in Environmental Sciences and Evaluation of Bioremediation

“…Panić and Górecki reviewed GC×GC in environmental analyses and monitoring and they indicated that the main challenge in environmental analysis is that the analytes are usually present in trace amounts in very complex matrices (Panić & Górecki, 2006). In overcoming this problem, GC×GC-MS is a very powerful and attractive system that has been successfully applied for powerful identification of polychlorinated dibenzodioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) (de Vos et al, 2011), polychlorinated biphenyls (PCBs) (Focant et al, 2004;Hoh et al, 2007), polychlorinated naphthalenes (PCNs) (Korytár et al, 2005), nonyl phenol (NP) (Eganhouse, et al, 2009), benzothiazoles, benzotriazoles, benzosulfonamides (Jover et al, 2009), Cl-/Br-PAH congeners (Ieda et al, 2011), pharmaceuticals and pesticides (Matamoros et al, 2010) in complex environmental samples.…”

Recent Applications of Comprehensive Two-Dimensional Gas Chromatography to Environmental Matrices

“…Few applications of GC×GC were shortly reported (Eganhouse et al, 2009;Matamoros et al, 2010a;Hilton et al, 2010) and will be discussed in the present chapter. Recently, GC×GC applications devoted to measurement of volatile and semivolatile organic compounds in air and aerosol were reviewed and discussed (Arsene et al, 2011, Hamilton, 2010.…”

“…GCGC was applied by Eganhouse et al (Eganhouse et al, 2009) to enhance the chromatographic resolution of highly similar compounds such as 4-nonylphenol isomers and facilitate identification of a number of previously unrecognized components. Among the 153-204 peaks attributed to alkylphenol, 59-664-NPs were identified (Figure 4).…”

Environmental analysis of chlorinated and brominated polycyclic aromatic hydrocarbons by comprehensive two-dimensional gas chromatography coupled to high-resolution time-of-flight mass spectrometry

“…They indicated that the main challenge in environmental analysis is that the analytes are usually present in trace amounts in very complex matrices. In overcoming this hurdle, GC × GC-MS is a very powerful and attractive system that has been successfully applied for the many kinds of environmental pollutants, such as PCDDs, PCDFs, polychlorinated biphenyls (PCBs) [13,14], polychlorinated naphthalenes (PCNs) [15], nonyl phenol (NP) [16][17][18], benzothiazoles, benzotriazoles, benzosulfonamides [19], pharmaceuticals and pesticides [20]. In one such paper, Hoh et al suggested that GC × GC coupled with high speed TOF-MS (50 Hz) with unit-mass resolution has the potential to lower costs and allow for the faster analysis of minor environmental pollutants, such as PCDD/Fs over the current predominant method [14].…”

“…For chlorinated anthracene or phenanthrene (C 14 H 10 ) and fluoranthene or pyrene (C 16 H 10 ) congeners, very small amounts of hepta chlorinated PAHs, were found in the soil sample. Also, for chlorinated benz[a]anthracene or chrysene (C 18 It suggested that there are a number of unconfirmed and highly substituted Cl-/Br-PAHs in the environmental samples as results of various reactions by chlorine, bromine and aromatic precursors (e.g., chlor-alkali processes, municipal waste incineration and automobile exhaust) [8,27]. Recently, Yamamoto et al reported that Cl-PAHs might have been formatted from brine electrolysis by graphite electrode abundantly contained pitch in the past [28].…”