Identification strategy for unknown pollutants using high-resolution mass spectrometry: Androgen-disrupting compounds identified through effect-directed analysis

Abstract

Effect-directed analysis has been applied to a river sediment sample of concern to identify the compounds responsible for the observed effects in an in vitro (anti-)androgenicity assay. For identification after non-target analysis performed on a high-resolution LTQ-Orbitrap, we developed a de novo identification strategy including physico-chemical parameters derived from the effect-directed analysis approach. With this identification strategy, we were able to handle the immense amount of data produced by non-target accurate mass analysis. The effect-directed analysis approach, together with the identification strategy, led to the successful identification of eight androgen-disrupting compounds belonging to very diverse compound classes: an oxygenated polyaromatic hydrocarbon, organophosphates, musks, and steroids. This is one of the first studies in the field of environmental analysis dealing with the difficult task of handling the large amount of data produced from non-target analysis. The combination of bioassay activity assessment, accurate mass measurement, and the identification and confirmation strategy is a promising approach for future identification of environmental key toxicants that are not included as priority pollutants in monitoring programs.Electronic supplementary materialThe online version of this article (doi:10.1007/s00216-011-4939-x) contains supplementary material, which is available to authorized users.

Trends in liquid chromatography coupled to high-resolution mass spectrometry for multi-residue analysis of organic micropollutants in aquatic environments

“…In general, these non-target screening techniques start with peak picking: a manual [81] or, in most cases, automated search for peaks in the chromatograms {i.e. non-target peak picking [7,11,[81][82][83]}. Subsequently, componentization aims at isotope, adduct and fragment grouping, resulting in thousands of unidentified analytes (~1000-10,000).…”

“…Another promising approach was the combined use of bioassays and LC-HRMS by Weiss et al [11] in effect-directed analysis (EDA) to prioritize substances showing ecotoxicological activity. They selected 59 analytes showing (anti-)androgenic activity in river-sediment extracts leading to the unequivocal identification of eight contaminants.…”

“…Two non-target screening studies in river sediment were also incorporated in Table 2 because of their interesting methodological approach [11,81]. In general, these non-target screening techniques start with peak picking: a manual [81] or, in most cases, automated search for peaks in the chromatograms {i.e.…”

“…Although, for many organic contaminants, their environmental fate is not well understood and detailed ecotoxicological knowledge is lacking, some contaminants have been shown to cause endocrine-disrupting effects {e.g., estrogens, steroids, surfactants and phthalates [10][11][12]}, behavioral changes {e.g., psychiatric drugs in fish [13]}, or other toxic effects in aquatic organism {e.g., antidepressants in marine snail [14], and anti-inflammatory drug diclofenac in fish [15]} at environmentally-relevant concentrations. Also, the presence of antibiotics has been related to increased bacterial resistance in wastewaters and the environment [16][17][18].…”

Post-incident monitoring to evaluate environmental damage from shipping incidents: Chemical and biological assessments

“…Should this technique not identify the cause(s) of effect then techniques that use either higher resolution separations (comprehensive GC Â GC) or GC coupled to high resolution TOF-MS may be alternative options . For polar compounds where GC is not an option then liquid chromatography coupled to accurate mass MS has previously been successfully used to identify the previously unknown causes of effect (Weiss et al, 2010). Other techniques that may assist the identification process include the use of molecular descriptors from bioassay data (Von Der Ohe et al, 2005;Kazius et al, 2005) or computational tools, such as molecular structure generation (MOLGEN) (Schymanski et al, 2009(Schymanski et al, , 2008.…”