Determination of Polycyclic Aromatic Hydrocarbons in Seafood by PLE-LC-APCI-MS/MS and Preliminary Risk Assessment of the Northeast Brazil Oil Spill

Profile of inorganic elements of seaweed from the Brazilian Northeast coast

The contents of 24 elements were determined in seven species of macroalgae collected in Ceara-Brazil, in the rainy and dry seasons of 2022. The samples were digested, and the analytes were quantified by ICP-OES and Hg by direct analyzer. The CRM CD-200 was analyzed for accuracy and obtained recoveries were higher than 95 %. The seaweed species have different inorganic element profiles with predominant elements being: Ca, K, Na, Mg and P. The Sargassum vulgare species stood out for its Hg and As contents (1.479 ± 0.005 mg kg-1 and 172 ± 6 mg kg-1, both in the rainy seasons). Ulva lactuca attracted attention for its high concentration of V (46.4 ± 3.4 mg kg-1, rainy season). In general, the elemental content levels in the macroalgae samples were higher in the rainy season. Long-term studies to comprehend the effect of seasonality on the elemental composition of seaweed must be carried out.

The role of habitat heterogeneity and timescales on the recovery of reef epifaunal communities affected by a massive oil spill in the tropics

From August 2019 to January 2020 the Brazilian Coast was impacted by the largest oil spill in the Tropical oceans ever since. Paiva Beach, one of the most preserved sandy beaches in the northeast tropical Brazilian coast, was among the most affected regions by the oil spill in October 2019. This area has important reef systems that harbor abundant macroalgal assemblages with very diverse epifaunal communities. The present study aims to evaluate the impacts of the 2019 oil spill on epifauna associated with the seaweed species Jania capillacea and Penicillus capitatus collected in Paiva Beach from July 2019 to October 2022, and use the interaction macroalgae/epifauna/timescale as a proxy to quantify the effects of oil spills on communities structure and recovery. The epifauna of both algae did not suffer severe changes in abundance immediately after the spill, however, the abundance of taxa like echinoderms, sea spiders (Pycnogonida) and peracarid crustaceans dropped during or soon after the event, whereas others, like sabellid worms, had strong increase in abundance, possibly related to the spill. Both phytal assemblages also had distinct temporal patterns in species diversity and abundance, the last being strongly correlated to amphipod abundance for some taxa. The epifauna of J. capillacea had a short-term tendency of decrease in taxonomic diversity, whereas the epifaunal communities of P. capitatus gained a few taxa in the months immediately after the disaster. The diversity profiles of both communities returned to pre-spill conditions a few months later, with a slower abundance recovery in J. capillacea. Local environmental characteristics like landscape heterogeneity, connectivity with other environments, and critical-species (mainly amphipods) were possibly the main buffering factors for the phytal communities after the oil spill.

Integrated analysis of marine biotoxins and contaminants of emerging concern in bivalve mollusks from Santa Catarina, Brazil

Santa Catarina is the main producer state of oysters and mussels in Brazil, reaching 98 % of national production. To assure the safety of bivalve mollusks production, control programs of marine biotoxins (MBs) have been continuously performed. Herein, the co-occurrence of MBs and contaminants of emerging concern (CECs) in oyster and mussels from the main production sites of Santa Catarina was reported, covering 178 compounds. Samples of wild and non-cultivated oysters and mussels were also assessed. Chemometric tools were used to evaluate and optimize several sample preparation techniques such as solid-liquid, ultrasound assisted, and pressurized liquid extraction. The optimized protocol was based on ultrasound assisted extraction followed by liquid chromatography coupled to tandem mass spectrometry. The results showed the incidence of several CECs and MBs. In the case of MBs, all results were below the regulatory limits for both cultivated and non-cultivated samples. Wild mollusks have shown a higher number of compounds. Regarding CECs, the more frequent compounds were caffeine, diclofenac, meloxicam, and sertraline. Domoic acid and okadaic acid were the main toxins detected. The results highlighted the need of monitoring for MBs and the potential of oyster and mussels as sentinel organisms to risk analysis of CECs in coastal regions. To the best of our knowledge, this is the first method to describe a simultaneous sample preparation and analysis of CECs and MBs in bivalve mollusks, as well as the first report of meloxicam and florfenicol in mussels and oysters.

Pressurized Liquid Extraction: A Powerful Tool to Implement Extraction and Purification of Food Contaminants

Pressurized liquid extraction (PLE) is considered an advanced extraction technique developed in the mid-1990s with the aim of saving time and reducing solvent with respect to traditional extraction processes. It is commonly used with solid and semi-solid samples and employs solvent extraction at elevated temperatures and pressures, always below the respective critical points, to maintain the solvent in a liquid state throughout the extraction procedure. The use of these particular pressure and temperature conditions changes the physicochemical properties of the extraction solvent, allowing easier and deeper penetration into the matrix to be extracted. Furthermore, the possibility to combine the extraction and clean-up steps by including a layer of an adsorbent retaining interfering compounds directly in the PLE extraction cells makes this technique extremely versatile and selective. After providing a background on the PLE technique and parameters to be optimized, the present review focuses on recent applications (published in the past 10 years) in the field of food contaminants. In particular, applications related to the extraction of environmental and processing contaminants, pesticides, residues of veterinary drugs, mycotoxins, parabens, ethyl carbamate, and fatty acid esters of 3-monochloro-1,2-propanediol and 2-monochloro-1,3-propanediol from different food matrices were considered.

Severe ecological impacts caused by one of the worst orphan oil spills worldwide

Orphan oil spills pose a severe risk to ocean sustainability; however, they are understudied. We provide the first synthetic assessment of short-term ecological impacts of the most extensive oil spill in tropical oceans, which affected 2900 km of Brazil's coastline in 2019. Oil ingestion, changes in sex ratio and size of animals, morphological abnormalities of larvae and eggs, mutagenic, behavioral, and morphological alterations, contamination by polycyclic aromatic hydrocarbons, and mortality were detected. A decrease in species richness and abundance of oil-sensitive animals, an increase in opportunistic and oil-tolerant organisms, and simplification of communities was observed. The impacts were observed in sponges, corals, mollusks, crustaceans, polychaetes, echinoderms, turtles, birds, fish, and mammals. The majority of studies were conducted on bioindicator substrate-associated organisms, with 68.4% of the studies examining the benthos, 21.2% the nekton, and 10.4% the plankton. Moreover, most of the current short-term impacts assessment studies were focused on the species level (66.7%), with fewer studies on the community level (19%), and even fewer on oil-affected ecosystems (14.3%). Oil-related impacts were detected in five sensitive habitats, including blue-carbon ecosystems (e.g., mangroves and seagrass beds) and coastal reefs. These results call for the development of new ocean-basin observation systems for orphan spills. Finally, we discuss how these mysterious oil spills from unknown sources pose a risk to sustainable development goals and ocean-based actions to tackle global climate change.

Condensed Phase Membrane Introduction Mass Spectrometry: A Direct Alternative to Fully Exploit the Mass Spectrometry Potential in Environmental Sample Analysis

Membrane introduction mass spectrometry (MIMS) is a direct mass spectrometry technique used to monitor online chemical systems or quickly quantify trace levels of different groups of compounds in complex matrices without extensive sample preparation steps and chromatographic separation. MIMS utilizes a thin, semi-permeable, and selective membrane that directly connects the sample and the mass spectrometer. The analytes in the sample are pre-concentrated by the membrane depending on their physicochemical properties and directly transferred, using different acceptor phases (gas, liquid or vacuum) to the mass spectrometer. Condensed phase (CP) MIMS use a liquid as a medium, extending the range to new applications to less-volatile compounds that are challenging or unsuitable to gas-phase MIMS. It directly allows the rapid quantification of selected compounds in complex matrices, the online monitoring of chemical reactions (in real-time), as well as in situ measurements. CP-MIMS has expanded beyond the measurement of several organic compounds because of the use of different types of liquid acceptor phases, geometries, dimensions, and mass spectrometers. This review surveys advancements of CP-MIMS and its applications to several molecules and matrices over the past 15 years.

Aqueous naphthenic acids and polycyclic aromatic hydrocarbons in a meso-scale spill tank affected by diluted bitumen analyzed directly by membrane introduction mass spectrometry

With the increasing use of unconventional, heavy crude oils there is growing interest in potential impacts of a diluted bitumen (DB) spill in marine and freshwater environments. DB has the potential to release several toxic, trace organic contaminants to the water column. Here, the aqueous concentrations and compositions of two classes of organic contaminants, naphthenic acids (NAs) and polycyclic aromatic hydrocarbons (PAHs), are followed over 8 weeks after a simulated spill of DB (10 L) into a freshwater mesocosm (1200 L) with river sediment (2.4 kg). These complex samples contain biogenic dissolved organic matter, inorganic ions, petroleum contaminants, suspended sediments, and oil droplets. We report the first use of condensed phase membrane introduction mass spectrometry (CP-MIMS) as a direct sampling platform in a complex multi-phase mesocosm spill tank study to measure trace aqueous phase contaminants with little to no sample preparation (dilution and/or pH adjustment). CP-MIMS provides complementary strengths to conventional analytical approaches (e.g., gas- or liquid chromatography mass spectrometry) by allowing the entire sample series to be screened quickly. Trace NAs are measured as carboxylates ([M-H]^-) using electrospray ionization and PAHs are detected as radical cations (M^+•) using liquid electron ionization coupled to a triple quadrupole mass spectrometer. The DB-affected mesocosm exhibits NA concentrations from 0.3 to 1.2 mg/L, which rise quickly over the first 2 - 5 days , then decrease slowly over the remainder of the study period. The NA profile (measured as the full scan in negative-electrospray ionization at nominal mass resolution) shifts to lower m/z with weathering, a process followed by principal component analysis of the normalized mass spectra. We couple CP-MIMS with high-resolution mass spectrometry to follow changes in molecular speciation over time, which reveals a concomitant shift from classical 'O₂' naphthenic acids to more oxidized analogues. Concentrations of PAHs and alkylated analogues (C1 - C4) in the DB-affected water range from 0 to 5 μg/L. Changes in PAH concentrations depend on ring number and degree of alkylation, with small and/or lightly alkylated (C0 - C2) PAH concentrations rising to a maximum in the first 4 - 8 days (100 - 200 h) before slowly decaying over the remainder of the study period. Larger and heavily alkylated (C3 - C4) PAH concentrations generally rise slower, with some species remaining below the detection limit throughout the study period (e.g., C₂₀H₁₂ class including benzo[a]pyrene). In contrast, a control mesocosm (without oil) exhibited NA concentrations below 0.05 mg/L and PAHs were below detection limit. Capitalizing on the rapid analytical workflow of CP-MIMS, we also investigate the impacts of sample filtration at the time of sampling (on NA and PAH data) and sample storage time (on NA data only).

Multi-Risk Source Oil Spill Risk Assessment Based on a Fuzzy Inference System

Oil is one of the most important sources of energy, about 25 percent of which comes from offshore sources. As a result, the transportation of oil tankers, and the construction of offshore oil platforms and subsea pipelines have increased, to facilitate offshore oil exploitation. However, most oil spill risk assessments analyze the impact of one risk source, and rarely consider multiple risk sources in the study area. This paper focuses on three risk sources that may cause oil spills in a certain area, and establishes an oil spill risk assessment model through a fuzzy inference system. Oil spill probabilities for different risk sources are calculated through the model. According to the definition of oil spill risk, the risk probability of multiple risk sources in the study area is obtained, which can provide technical support for regional oil spill emergency capacity and emergency resource allocation.