Prioritizing Unknown Transformation Products from Biologically-Treated Wastewater Using High-Resolution Mass Spectrometry, Multivariate Statistics, and Metabolic Logic.

Incomplete micropollutant elimination in wastewater treatment plants (WWTPs) results in transformation products (TPs) that are released into the environment. Improvements in analytical technologies have allowed researchers to identify several TPs from specific micropollutants but an overall picture of nontarget TPs is missing. In this study, we addressed this challenge by applying multivariate statistics to data collected with liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS) and subsequent tandem HRMS (MS/MS) in order to characterize peaks detected in the influent and effluent of a WWTP. Known biotransformation reactions were used to link potential parent compounds and TPs, while the structural similarity of these pairs hypothesized by MS/MS similarity was used for further prioritization. The methodology was validated with a set of spiked compounds, which included 25 parent/TP pairs for which analytical standards were available. This procedure was then applied to nontarget data, and 20 potential parent and TP pairs were selected for identification. In summary, primarily a surfactant homologue series, with associated TPs, was detected. Some obstacles still remain, including spectral interferences from coeluting compounds and identification of TPs, whose structures are less likely to be present in compound databases. The workflow was developed using openly accessible tools and, after parameter adjustment, could be applied to any data set with before and after information about various biological or chemical processes.

[1]  Martin Krauss,et al.  Linking mutagenic activity to micropollutant concentrations in wastewater samples by partial least square regression and subsequent identification of variables. , 2015, Chemosphere.

[2]  K. Tollefsen,et al.  Effect-directed identification of naphthenic acids as important in vitro xeno-estrogens and anti-androgens in North sea offshore produced water discharges. , 2009, Environmental science & technology.

[3]  Ralf Schulz,et al.  Biotransformation of the antiviral drugs acyclovir and penciclovir in activated sludge treatment. , 2011, Environmental science & technology.

[4]  R. Samperi,et al.  Fate of natural estrogen conjugates in municipal sewage transport and treatment facilities. , 2003, The Science of the total environment.

[5]  D. Barceló,et al.  Fate and toxicity of emerging pollutants, their metabolites and transformation products in the aquatic environment , 2008 .

[6]  Martin Krauss,et al.  LC–high resolution MS in environmental analysis: from target screening to the identification of unknowns , 2010, Analytical and bioanalytical chemistry.

[7]  Emma L. Schymanski,et al.  Biotransformation of benzotriazoles: insights from transformation product identification and compound-specific isotope analysis. , 2014, Environmental science & technology.

[8]  W. Eckhoff,et al.  Removal and environmental exposure of alcohol ethoxylates in US sewage treatment. , 2006, Ecotoxicology and environmental safety.

[9]  Lubertus Bijlsma,et al.  Investigation of pharmaceuticals and illicit drugs in waters by liquid chromatography-high-resolution mass spectrometry , 2014 .

[10]  D. Barceló,et al.  Effects of pesticides and pharmaceuticals on biofilms in a highly impacted river. , 2013, Environmental pollution.

[11]  Emma L. Schymanski,et al.  Automatic recalibration and processing of tandem mass spectra using formula annotation. , 2013, Journal of mass spectrometry : JMS.

[12]  Thomas Letzel,et al.  Non-target screening with high-resolution mass spectrometry: critical review using a collaborative trial on water analysis , 2015, Analytical and Bioanalytical Chemistry.

[13]  Ana Agüera,et al.  New trends in the analytical determination of emerging contaminants and their transformation products in environmental waters , 2013, Environmental Science and Pollution Research.

[14]  C. Stamm,et al.  Reducing the discharge of micropollutants in the aquatic environment: the benefits of upgrading wastewater treatment plants. , 2014, Environmental science & technology.

[15]  Christa S. McArdell,et al.  Multiresidue analysis of 88 polar organic micropollutants in ground, surface and wastewater using online mixed-bed multilayer solid-phase extraction coupled to high performance liquid chromatography-tandem mass spectrometry. , 2012, Journal of chromatography. A.

[16]  A. Fernández-Alba,et al.  Application of liquid chromatography/quadrupole-linear Ion trap mass spectrometry and time-of-flight mass spectrometry to the determination of pharmaceuticals and related contaminants in wastewater. , 2007, Analytical chemistry.

[17]  Christian Zwiener,et al.  New developments in the trace analysis of organic water pollutants , 2012, Applied Microbiology and Biotechnology.

[18]  Heinz Singer,et al.  High-throughput identification of microbial transformation products of organic micropollutants. , 2010, Environmental science & technology.

[19]  Emma L. Schymanski,et al.  Identifying small molecules via high resolution mass spectrometry: communicating confidence. , 2014, Environmental science & technology.

[20]  D. Scott,et al.  Optimization and testing of mass spectral library search algorithms for compound identification , 1994, Journal of the American Society for Mass Spectrometry.

[21]  A. Fernández-Alba,et al.  Use of an accurate-mass database for the systematic identification of transformation products of organic contaminants in wastewater effluents. , 2011, Journal of chromatography. A.

[22]  Steffen Neumann,et al.  MetFusion: integration of compound identification strategies. , 2013, Journal of mass spectrometry : JMS.

[23]  Natalie I. Tasman,et al.  A Cross-platform Toolkit for Mass Spectrometry and Proteomics , 2012, Nature Biotechnology.

[24]  B. Brownawell,et al.  Environmental analysis of alcohol ethoxylates and nonylphenol ethoxylate metabolites by ultra-performance liquid chromatography–tandem mass spectrometry , 2012, Analytical and Bioanalytical Chemistry.

[25]  P. Legendre,et al.  SPECIES ASSEMBLAGES AND INDICATOR SPECIES:THE NEED FOR A FLEXIBLE ASYMMETRICAL APPROACH , 1997 .

[26]  Wolfgang Schulz,et al.  A new approach to data evaluation in the non-target screening of organic trace substances in water analysis. , 2011, Chemosphere.

[27]  Martin Krauss,et al.  Identification of novel micropollutants in wastewater by a combination of suspect and nontarget screening. , 2014, Environmental pollution.

[28]  D. M. Stamper,et al.  Biodegradation of the acetanilide herbicides alachlor, metolachlor, and propachlor. , 1998, Critical reviews in microbiology.

[29]  R. Kookana,et al.  Environmental fate of alkylphenols and alkylphenol ethoxylates--a review. , 2002, Environment international.

[30]  Pim E. G. Leonards,et al.  Identification strategy for unknown pollutants using high-resolution mass spectrometry: Androgen-disrupting compounds identified through effect-directed analysis , 2011, Analytical and bioanalytical chemistry.

[31]  F. Ventura,et al.  Occurrence of psychoactive stimulatory drugs in wastewaters in north-eastern Spain. , 2008, The Science of the total environment.

[32]  P. Dearmond,et al.  Rapid liquid chromatography-tandem mass spectrometry-based method for the analysis of alcohol ethoxylates and alkylphenol ethoxylates in environmental samples. , 2013, Journal of chromatography. A.

[33]  T. Ternes,et al.  Elucidation of the transformation pathway of the opium alkaloid codeine in biological wastewater treatment. , 2011, Environmental science & technology.

[34]  Emma L. Schymanski,et al.  Suspect and nontarget screening approaches to identify organic contaminant records in lake sediments , 2014, Analytical and Bioanalytical Chemistry.

[35]  F. Hernández,et al.  Investigation of drugs of abuse and relevant metabolites in Dutch sewage water by liquid chromatography coupled to high resolution mass spectrometry. , 2012, Chemosphere.

[36]  Matthias Müller-Hannemann,et al.  In silico fragmentation for computer assisted identification of metabolite mass spectra , 2010, BMC Bioinformatics.

[37]  W. Giger Hydrophilic and amphiphilic water pollutants: using advanced analytical methods for classic and emerging contaminants , 2009, Analytical and bioanalytical chemistry.

[38]  Francesco Corona,et al.  Accelerated isotope fine structure calculation using pruned transition trees. , 2015, Analytical chemistry.

[39]  Beate I. Escher,et al.  Recent advances in environmental risk assessment of transformation products. , 2011, Environmental science & technology.

[40]  René P Schwarzenbach,et al.  Identification of transformation products of organic contaminants in natural waters by computer-aided prediction and high-resolution mass spectrometry. , 2009, Environmental science & technology.

[41]  Emma L. Schymanski,et al.  Strategies to characterize polar organic contamination in wastewater: exploring the capability of high resolution mass spectrometry. , 2014, Environmental science & technology.

[42]  F. Hernández,et al.  Current use of high-resolution mass spectrometry in the environmental sciences , 2012, Analytical and Bioanalytical Chemistry.