Characterization of Halogenated Organic Compounds in Pelagic Sharks and Sea Turtles Using a Nontargeted Approach

Abstract

Halogenated organic compounds (HOCs) in marine species collected from the Atlantic Ocean [3 shortfin mako (Isurus oxyrinchus) and 1 porbeagle (Lamna nasus)], and 12 sea turtles collected from the Pacific Ocean [3 loggerhead (Caretta caretta), 3 green (Chelonia mydas), 3 olive ridley (Lepidochelys olivacea), and 3 hawksbill (Eretmochelys imbricata)] were analyzed with a nontargeted analytical method using two-dimensional gas chromatography coupled to high-resolution time-of-flight mass spectrometry. Sharks and sea turtles had distinct HOC profiles. Halogenated methoxyphenols (halo-MeOPs) were the most abundant compound class identified in sea turtle livers, while polychlorinated biphenyls (PCBs) were the most abundant in shark livers. In addition to legacy contaminants and halo-MeOPs, a total of 110 nontargeted/novel HOCs (NHOCs) were observed in the shark livers. Shortfin mako collected from the northern Gulf of Mexico contained the largest number (89) and most diverse structural classes of NHOCs. Among all NHOCs, a group of compounds with the elemental composition C 14 H 12−n Cl n (n = 5−8) exhibited the highest concentrations, followed by chlorocarbazoles and tris(chlorophenyl) methanes (TCPMs). Using nontargeted workflows, a variety of known and unknown HOCs were observed, which demonstrate the need to develop more complete chemical profiles in the marine environment.

Nontarget Insights into the Fate of Cl-/Br-Containing DOM in Leachate during Membrane Treatment

“…The mass feature ratio extracted through mixed-SPE is 1.10–1.72 times higher than that of PPL-SPE across the five treatment plants. While variations in published studies (e.g., formula assignment strategies, mass range, element composition, pretreatment, and analytical conditions) must be considered, the amount of Cl-/Br-containing DOM in leachate matrices appears considerably higher compared to sewage and biota samples, thereby heightening the risk. Under this limited benchmark, the lowest is up to 2.10 times, while considering all of the leachates and concentrates, the highest is up to 5.03 times.…”

“…Unknown Cl-/Br-containing DOM in complex waste-derived water samples can be promisingly interpreted via halogenated isotopic ratio and mass defect filter strategies, not limited to biota and natural samples. 1,17,21,22 Meanwhile, mainstream sample pretreatment for DOM analysis via HRMS should be optimized accordingly to decipher more Cl-and Br-containing DOM in the leachate matrices. Solid-phase extraction (SPE) has become a wellestablished and widespread DOM isolation method with high organic matter recovery and less solvent consumption, wherein sorbents, such as XAD, silica-C18, modified styrene divinylbenzene polymer (PPL), and hydrophilic−lipophilic polymer (HLB), are most commonly used.…”

Sources and environmental fate of halomethoxybenzenes

“…Earlier work clearly demonstrated that a naturally produced compound such as DAME is persistent in the environment (10) and able to bioaccumulate in organisms (7)(8)(9). DAME and DA exhibit antimicrobial properties that may serve as the wood fungi's chemical defense against organisms that compete for the same substrate (19).Therefore, it is possible that they exert toxic effects similar to those other biocides.…”

Identification and Prioritization of Environmental Organic Pollutants: From an Analytical and Toxicological Perspective

“…Nevertheless, the sources of such naturally occurring substances are often difficult to define. Polyhalogenated carbazoles are a group of widely spread contaminants found in aquatic species . The compounds are known to have dual origins, produced naturally by marine cyanobacteria and also synthesized as intermediates to meet the industry needs since the 1900s …”