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An online SPE-LC-HRMS method was developed to monitor the consumption of 18 drugs of abuse (DOAs) including amphetamines, opioids, cocainics, cannabinoids, lysergics, and their corresponding metabolites in a well characterized college campus setting via wastewater analysis. Filtered and diluted (10×) sewage water samples (5 mL inj.) were automatically pre-concentrated and analyzed in 15 min using a Thermo EQuan MAX online SPE system equipped with a HyperSep™ Retain PEP (20×2.1 mm×12 μm) SPE column and a Hypersil Gold™ aQ (150×2.1 mm×3 μm) analytical column. A Q Exactive™ Hybrid Quadrupole-Orbitrap HRMS was used in full scan mode (R=140,000) for positive identification, and quantitation of target compounds. Method detection limits for all analytes ranged between 0.6 and 1.7 ng/L in sewage. A total of 14 DOAs were detected from two different locations (dorms and main college campus) within a one-year period. Most frequently detected drugs throughout the entire study were amphetamine (>96%) and THC's metabolite 11-nor-9-carboxy-Δ-9-THC (>100%) with maximum concentrations of 5956 and 2413 ng/L respectively. Daily doses per 1000 people were determined in order to assess consumption of THC, amphetamine, heroin and cocaine, in both dorms and main campus.

Dioctyl sulfosuccinate (DOSS) is one of the main components of Corexit® EC9500A, a chemical dispersant formulation used at the surface and at depth during the response to the Deepwater Horizon incident. Despite being a high volume use chemical, data on its environmental stability are scarce. Hydrolysis and photodegradation of DOSS in both pure water and seawater were reported in the present study. DOSS photodegraded much faster under ultraviolet light source (254 nm, with half-life in hours) compared to relevant environmental light sources i.e., 350 nm and solar simulator (with half-lives in days). LC/MS-MS analysis of hydrolysis and photo-irradiated samples showed the presence of a common degradation product. MS/MS fragmentation of that product indicated a substitution of an octyl group by a hydroxyl group with a corresponding formula of C12H21O7S, which was confirmed by HRMS detection (Q-TOF, m/z 309.1017, +1.29 ppm).