Contrast Enhancement for the Recovery of Obliterated Serial Numbers in Different Polymers by Correlated Raman Imaging of Strain, Phonon Lifetime, and Strain-Induced Anisotropy.

In the field of forensic science, we have recently introduced Raman imaging as a promising nondestructive technique to efficiently recover obliterated serial numbers in polycarbonate. The present study is extending the investigation toward different polymers for the reconstruction of abraded information by Raman spectroscopy. Samples of polyethylene, nylon, and nylatron, which are mainly used in items such as firearms, banknotes, and package materials, are investigated by monitoring the vibrational modes which are most susceptible to peak shifts and changes in the full width at half-maximum (fwhm) and peak intensity ratios. In all cases, the most affected peak depends on the polymer's 3D structure and displays a ∼1 cm-1 shift and a broadening above ∼2 cm-1, as well as a relative intensity change of over 50%, more than enough for a successful recovery through confocal imaging. Depending on the polymer's structural arrangement, any of the three contributions prevails for the strongest contrast. The propagation of the plastic deformations is mainly affected by the Young's modulus of the material, due to a change in its elasticity. The shift, the width, and the relative intensity of the Raman peaks being three independent parameters, they can be correlated to enhance the contrast and thus to accelerate the image acquisition or to enhance statistical significance.

Phytochemical Screening of Quaking Aspen (Populus tremuloides) Extracts by UPLC-QTOF-MS and Evaluation of their Antimicrobial Activity.

The continual emergence of pathogen resistance is a recurring challenge and pushes for the development of antimicrobial compounds. Here, we investigated compounds from quaking aspen trees (Populus tremuloides) as potential antimicrobial agents. Several extractions using different solvents were realized, and corresponding antimicrobial activity was tested against eight microorganisms. Results revealed that polar extraction solvents including water, ethanol and methanol gave the best extraction yields (>15.07%). Minimal inhibition concentration (MIC) and minimal bactericidal/fungicidal concentration (MBC/MFC) demonstrated that water extracts had the best antimicrobial activity by a weak to moderate inhibition of growth of all eight tested microorganisms in addition to having a bactericidal effect on three of them. The quaking aspen methanol extract also displayed antimicrobial activity but to a lower level than the water extract. Ultra-performance liquid chromatography quadrupole time-of flight mass spectrometry (UPLC-QTOF-MS) analysis led to the identification of 92 compounds, mainly polyphenols in both extracts, with 22 molecules previously known for their antimicrobial properties. According to the relative abundance, 4-hydroxybenzaldehyde (5.44% in methanol extract) and kaempferol (5.03% in water extract) were the most abundant antimicrobial compounds. Among antimicrobial molecules identified, nine were from the flavonoid family. The results of our study demonstrate the interest of using quaking aspen as source of antimicrobial compounds.

Reconstruction of Obliterated Characters in Polycarbonate through Spectral Imaging.

In forensic sciences, there is an increasing demand for nondestructive and reliable methods to retrieve obliterated information in polymers. This study demonstrates a case study for the potential of Raman spectroscopy to reconstruct abraded serial numbers. Residual strain and local variations in the structural arrangement are nondestructively imaged through peak shifts and variations of the full width at half-maximum of specific Raman lines, respectively. We qualitatively validate our approach by successfully recovering an obliterated letter stamped with a pressure of ∼170 MPa in a polycarbonate sample, with a subsequent quantitative statistical analysis. The detection threshold is estimated from the propagation depth of plastic deformations to a value of ∼750-800 µm, substantially larger than typical obliteration depths, 200 µm in our case for an initial profile depth of 120 µm.

Responses of freshwater mussel (Elliptio complanata) hemocytes exposed in vitro to crude extracts of Microcystis aeruginosa and Lyngbya wollei.

Lyngbya wollei is a benthic filamentous cyanobacterium that produces a toxin analogous to the neurotoxic saxitoxin known as lyngbyatoxin (LYNGTX). Microcystis aeruginosa form blooms in the pelagic area of eutrophic lakes and produce a series of potent hepatotoxins-microcystins (MCYST). The aim of this study in vitro study was to examine the difference between the crude extracts of either M. aeruginosa or L. wollei toward the immune system of Elliptio complanata mussels. Freshly isolated hemolymph was plated and exposed to the crude extract of each species at LYNGTX or MCYST equivalent concentrations of 5, 10 and 25 µg/L for 18 h. Immunocompetence was characterized by following changes in hemocyte numbers, metabolic activity (viability), and phagocytosis. Hemocyte counts were not affected, indicating no turnover of hemocytes. Hemocyte metabolic activity was higher in cells exposed to crude extracts of L. wollei. Exposure to L. wollei extracts led to decreased pro-inflammatory precursors such as reactive oxygen species (ROS) and cyclooxygenase (COX) activities. Phagocytosis increased at 25 µg/L for both types of crude extracts. However, hemocytes exposed to crude extracts of M. aeruginosa produced more ROS and COX compared to hemocytes exposed to crude extracts of L. wollei. In conclusion, the data suggest that the crude extract of M. aeruginosa was more toxic than crude extract of L. wollei to mussel hemocytes.

Temporal and seasonal variation in acetylcholinesterase activity and glutathione-S-transferase in amphipods collected in mats of Lyngbya wollei in the St-Lawrence River (Canada).

Mats of filamentous algae Lyngbya wollei cover large areas on top of the sediments along the St-Lawrence River. Like most cyanobacteria, L. wollei produce toxins, named lyngbyatoxin (LYNGTX), an analog of saxitoxin. In order to verify the neurotoxic potential of these filamentous cyanobacteria, we collected amphipods within local vegetation at three sites in summer months: a site rich in L. wollei (Lake St-Louis [LSL]) and two urban sites composed of macrophytes but devoid of L. wollei mats (Richelieu River [RICH] and L'Assomption River [ASSO] outlets). The body weight of each amphipod was measured, and the neurotoxicity was estimated with the measurement of acetylcholinesterase (AChE) and glutathione-s-transferase (GST) activities. Levels of protein-bound phosphates were also evaluated, to rule out contamination by Microcystis sp. The results showed that the activity of acetylcholinesterase measured in amphipods in ASSO and RICH was lower than the activity found in amphipods collected in L. wollei mats in LSL. In addition, amphipods found in L. wollei mats at the LSL site have significantly higher GST activity than those located at the two devoid sites, RICH and ASSO. No significant change was observed for protein-bound phosphate levels. This study suggests that the presence of L. wollei triggers potential toxicity.

Energy status and immune system alterations in Elliptio complanata after ingestion of cyanobacteria Anabaena flos-aquae.

Cyanobacteria have often been described as nutritionally poor for herbivorous organisms. To gain additional information on the potential impacts of invertebrates feeding on cyanobacteria, we fed Elliptio complanata mussels with two types of algae: Anabaena flos-aquae (cyanobacteria) and Pseudokirchneriella subcapitata (green algae). Physiological parameters were examined at the energy status, immune system and oxidative stress levels. Energy status was examined by following the rate of electron transport activity in mitochondria (a measure of cellular energy expense) and lipid/sugar stores in the visceral mass. The cyanobacteria were not actively producing toxins. Based on the digestive gland index, the mussels fed equally on either regime. However, the energy status in mussels fed A. flos-aquae revealed that the total sugar was lower in the digestive gland, whereas mitochondrial electron transport activity (MET), once corrected against the digestive gland somatic index, showed increased energy expenses. Acetylcholinesterase activity and lipid peroxidation (LPO) were also higher in mussels fed with A. flos-aquae compared with mussels fed with P. subcapitata. LPO was correlated by mitochondrial activity in both the digestive gland and gills, suggesting that oxidative stress resulted from metabolic respiration. Immunocompetence (phagocytic activity, natural killer cell-like activity, haemocyte count and viability) and humoral level of lysozyme were not affected in mussels by the algae or cyanobacteria regime. Moreover, the xenobiotic conjugating enzyme, glutathione S-transferase, hemoprotein oxidase and vitellogenin-like proteins were not affected in mussel organs via ingestion of A. flos-aquae. Our study suggests that ingestion of cyanobacteria leads to increased energy expenses, oxidative stress and increased acetylcholine turnover in mussels.

Method development for the quantification of lead levels in whole blood sampled on Mitra® with VAMS® tips by inductively coupled plasma-MS/MS.

Background: Lead is harmful for humans by having adverse effects on different biological systems. Venepuncture is the gold standard for blood lead level analysis, but this method has many flaws. The goal of this research was to develop and validate a more practical approach for blood sampling. Materials & methods: Mitra® devices based on VAMS® and inductively coupled plasma-MS/MS technologies were employed. Performance evaluation of the newly developed method was also performed by comparing it versus a commonly used method at the Centre de Toxicologie du Québec for blood lead level analysis. Results: Comparison showed no signs of significant difference between the two methods. Conclusion: VAMS may be a useful alternative sampling approach for further research on blood lead analysis and possibly for many other trace elements.

A comprehensive analytical process, from NPS threat identification to systematic screening: Method validation and one-year prevalence study.

Several New Psychoactive Substances (NPS) enter the illicit drug market each year. This constant evolution of compounds to screen is challenging to law enforcement and drug chemists, and even more so to forensic toxicologists, who need to detect such compounds which might be at low concentrations in complex biological matrices. While some technological solutions are better suited than others to address such a challenge (e.g., high resolution mass spectrometry), laboratories with limited instrumental and financial resources are faced with a complex task: systematically screening for a rapidly evolving NPS panel using an accredited method run on standard equipment (e.g., liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS)). This work presents a solution to this challenge: a complete workflow from the detection of a regional NPS threat to its implementation in a method accredited under the ISO 17025:2017 norm. Initial LC-MS/MS method included 55 NPS and metabolites (31 Novel Synthetic Opioids (NSO), 22 NSO metabolites and 2 designer benzodiazepines). Following their identification as relevant territorial threats, flualprazolam, then isotonitazene, were added to the contingent. By relying on development aiming for maximal integration to the current analysis workflow, systematic NPS screening using this method was easily implemented. Between March 2019 and March 2020, the 5 079 forensic cases analyzed in the province of Québec (Canada) revealed a NPS positivity rate of 3.4%. While 94% involved designer benzodiazepines, 5% involved NSO. This process, combining high efficiency, simple detection technology, ISO accreditation and rapid response to new threats resulted in a four-fold increase in NPS detection.

Development of electrospun lignin nanofibers for the adsorption of pharmaceutical contaminants in wastewater.

Emerging contaminants present a challenge for water preservation, threatening humans' health and all ecosystems. They consist of a variety of molecules ranging from pharmaceutical and personal care products to pesticides and endocrine disruptors detectable in wastewater, sewage effluent, surface water, drinking water, and ground waters at trace level concentrations (e.g., ng/L, µg/L). Conventional wastewater treatment plants (WWTPs) possess low efficiency to remove them. Therefore, new technologies capable of removing such residues are needed. Lignin recognized as a renewable and abundant biopolymer is transformed through electrospinning into an anionic nanofibrous nonwoven adsorbent to extract those contaminants and dispose them safely. Electrospinning allows the manufacture of fibers at the micro- or nanoscale under the influence of an electric current. In this study, nanofibers of alkali lignin and a co-polymer, poly(vinyl alcohol), were developed and tested on the adsorption of a pharmaceutical contaminant (fluoxetine) in an aqueous solution. Results showed that the lignin nanofibers, of 156 nm in diameter, adsorbed 70% of fluoxetine in solution which corresponds to 32 ppm of contaminants removed in water.

Challenges Related to Three Cases of Fatal Intoxication to Multiple Novel Synthetic Opioids.

In the last two decades, a large increase in opioid overdose death rates has been recorded in North America. This phenomenon, related to the misuse of prescription opioids, has been dubbed an "opioids crisis". Recent years have seen the entrance of novel synthetic opioids (NSO) on the market, compounding the fatal intoxications issue. This brings several challenges for forensic toxicology laboratories: an increased number of cases, a large number of novel structurally similar compounds to include in screening analytical methods, the low concentration of drugs in biological fluids, and the challenging interpretation in the absence of sufficient literature. Three cases of fatal intoxication highlighting those challenges are presented, complete with post-mortem concentrations in cardiac blood, femoral blood and urine. Toxicological screening and quantitative analyses were performed on the biological specimens. In the first and second cases, furanylfentanyl, U-47700 and 4-anilino-N-phenethylpiperidine (4-ANPP) were detected at similar concentrations in cardiac blood. In the third case, a total of seventeen different NSO were detected. All intoxications showed a combination of NSO and other drugs. These three cases appear to be the harbinger of an increased NSO prevalence in the province of Québec, Canada.

Antimicrobial activity and chemical composition of white birch (Betula papyrifera Marshall) bark extracts.

Extracts from white birch have been reported to possess antimicrobial properties, but no study has linked the chemical composition of bark extract with antimicrobial activity. This study aimed to identify white birch (Betula papyrifera Marshall) bark extracts with antimicrobial activity and elucidate its composition. In order to obtain the highest extraction yield, bark residues >3 mm were retained for extraction. A total of 10 extraction solvents were used to determine the extraction yield of each of them. Methanol and ethanol solvents extracted a greater proportion of molecules. When tested on eight microorganism species, the water extract proved to have the best antimicrobial potential followed by the methanol extract. The water extract inhibited all microorganisms at low concentration with minimal inhibitory concentration between 0.83 and 1.67 mg/ml. Using ultraperformance liquid chromatography coupled to a time-of-flight quadrupole mass spectrometer, several molecules that have already been studied for their antimicrobial properties were identified in water and methanol extracts. Catechol was identified as one of the dominant components in white birch bark water extract, and its antimicrobial activity has already been demonstrated, suggesting that catechol could be one of the main components contributing to the antimicrobial activity of this extract. Thus, extractives from forestry wastes have potential for new applications to valorize these residues.

Determination of carbamazepine in aquatic organisms by liquid-liquid extraction and liquid chromatography-tandem mass spectrometry.

A sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been developed for the determination of carbamazepine in microgram quantities of crustacean Thamnocephalus platyurus and the algae Pseudokirchneriella subcapitata at the ng L(-1) level. This fully validated method applied to a bioaccumulation study was found suitable for the detection of carbamazepine in small aquatic tissues.

Analysis of emerging contaminants in water and solid samples using high resolution mass spectrometry with a Q Exactive orbital ion trap and estrogenic activity with YES-assay.

Trace emerging contaminants (ECs) occur in both waste and surface waters that are rich in particulates that have been found to sorb several organic contaminants. An analytical method based on off-line solid-phase extraction (SPE) followed by liquid chromatography-mass spectrometry (LC-MS) analysis was developed for the detection and quantification of 31 ECs from surface water, wastewater, suspended particulate matter (SPM) as well as sediments. Lyophilized sediments and air-dried SPM were subjected to ultrasonic extraction. Water samples and extracts were then concentrated and cleaned-up by off-line SPE. Quantification was realized using a Q Exactive mass spectrometer in both full scan (FS) and MS2 modes. These two modes were optimized and compared to determine which one was the most suitable for each matrix studied. Yeast estrogen screen assay (YES-assay) adapted from the direct measurement of estrogenic activity without sample extraction was tested on filtered wastewater samples. An endocrine disrupting effect was detected in all effluent samples analyzed with estradiol equivalent concentrations ranging from 4.4 to 720 ng eq E2 L-1 for the WWTP-1 and 6.5-42 ng eq E2 L-1 for the WWTP-2. The analytical methods were also applied on six samples of surface water, the corresponding SPM, the sediments and thirty-nine effluent samples from two wastewater treatment plants (WWTPs) sampled over a period of five months (February to June 2014).

Ozone oxidation of antidepressants in wastewater -Treatment evaluation and characterization of new by-products by LC-QToFMS.

BACKGROUND: The fate of 14 antidepressants along with their respective N-desmethyl metabolites and the anticonvulsive drug carbamazepine was examined in a primary sewage treatment plant (STP) and following advanced treatments with ozone (O3). The concentrations of each pharmaceutical compound were determined in raw sewage, effluent and sewage sludge samples by LC-MS/MS analysis. The occurrence of antidepressant by-products formed in treated effluent after ozonation was also investigated. RESULTS: Current primary treatments using physical and chemical processes removed little of the compounds (mean removal efficiency: 19%). Experimental sorption coefficients (Kd) of each studied compounds were also calculated. Sorption of venlafaxine, desmethylvenlafaxine, and carbamazepine on sludge was assumed to be negligible (log Kd ≤ 2), but higher sorption behavior can be expected for sertraline (log Kd ≥ 4). Ozonation treatment with O3 (5 mg/L) led to a satisfactory mean removal efficiency of 88% of the compounds. Screening of the final ozone-treated effluent samples by high resolution-mass spectrometry (LC-QqToFMS) did confirm the presence of related N-oxide by-products. CONCLUSION: Effluent ozonation led to higher mean removal efficiencies than current primary treatment, and therefore represented a promising strategy for the elimination of antidepressants in urban wastewaters. However, the use of O3 produced by-products with unknown toxicity.

Detection and confirmation of saxitoxin analogues in freshwater benthic Lyngbya wollei algae collected in the St. Lawrence River (Canada) by liquid chromatography-tandem mass spectrometry.

The presence of cyanotoxins in benthic Lyngbya wollei algae samples collected in a fluvial lake along the St. Lawrence River, Canada, was investigated using a multi-toxins method. Hydrophilic interaction liquid chromatography (HILIC) and reverse phased liquid chromatography (RPLC) were coupled to triple quadrupole mass spectrometry (LC-QqQMS) for quantification and to quadrupole-time of flight mass spectrometry (LC-QqTOFMS) for screening and confirmation. The presence of two saxitoxin analogues, LWTX-1 and LWTX-6, was confirmed in benthic Lyngbya wollei algae samples. Concentration of LWTX-1 was between 209±5 and 279±9 µg g(-1). No other targeted cyanotoxin (such as anatoxin-a, nodularin, microcystin-LR, microcystins-RR and saxitoxin) was found in the samples. The presence of LWTX-6 was observed by using a screening approach based on an in-house database of cyanotoxins, an algorithm of identification and high resolution mass spectrometry measurements on the precursor and product ions. This work demonstrates the need for more research on the fate of benthic cyanotoxins in aquatic ecosystems such the St. Lawrence River.

Distribution of antidepressants and their metabolites in brook trout exposed to municipal wastewaters before and after ozone treatment--evidence of biological effects.

This study examined the tissues distribution of selected serotonin reuptake inhibitors (SSRIs) in brook trout exposed for 3 months to continuous flow-through primary-treated effluent before and after ozone treatment. A reliable analytical method was developed for the quantification of trace amounts of antidepressants in small tissue homogenate extracts. Levels of six antidepressants and four of their N-desmethyl metabolites were determined using liquid chromatography-tandem mass spectrometry. Significant amounts of the SSRIs were found in fish tissue-in decreasing order: liver>brain>muscle. Sertraline and its metabolite desmethylsertraline were the predominant substances observed in most tissues (0.04-10.3 ng g(-1)). However, less SSRIs (0.08-1.17 ng g(-1)) were bioaccumulated in the ozonated effluent. The early molecular effects of these SSRIs on the Na/K-dependent ATPase pump activity in brain synaptosomes where also investigated in vitro and in fish exposed to the municipal effluents. With respect to their potential biological effects, in vitro exposure to selected SSRIs induced a reduction of the brain Na/K-ATPase activity in synaptosomes in a dose-dependent manner. Results showed that Na/K-ATPase activity was readily inhibited by exposure to municipal effluent before and, to a lesser extent, after ozone treatment. Moreover, the Na/K-ATPase activity was significantly and negatively correlated with brain tissue concentrations of fluoxetine (r=-0.57; p<0.03), desmethylsertraline (r=-0.84; p<0.001), and sertraline (r=-0.82; p<0.001). The present study reveals that SSRIs are readily available in fish, biologically active and corroborates previous findings on the serotonergic properties of municipal effluents to aquatic organisms.

Toxic effects and bioaccumulation of carbamazepine evaluated by biomarkers measured in organisms of different trophic levels.

The antiepileptic drug carbamazapine (CBZ) readily persists in sewage-water treatment plant wastewaters and finds its way into receiving water bodies. Our study sought to examine the bioaccumulation and toxicity of CBZ using an experimental aquatic trophic chain composed of the green alga, Pseudokirchneriella subcapitata, the crustacean, Thamnocephalus platyurus, and the cnidarian, Hydra attenuata. Bioaccumulation of CBZ was estimated by liquid chromatography-tandem mass spectrometry and revealed bioaccumulation factors of 2.2 and 12.6, respectively, in algae and crustaceans. No significant bioaccumulation was observed in H. attenuata. In T. platyurus, a strong stimulation of global heme oxidase (HO) (76%), and glutathione-S-transferase activity (130%) but a drastic inhibition of cytochrome P450 3A-like activity was found which suggests alteration of enzyme activity by CBZ. However, in the hydranth H. attenuata, an increase in both global cytochrome and cytochrome P450 3A-like activity was found, while GST activity was inhibited. Lipid peroxidation was reduced in T. platyurus and H. attenuata suggesting that redox activity of the lipophilic CBZ was at play. This study highlighted the processes of carbamazepine toxicity transfer between trophic levels in aquatic organisms.

Determination of six anti-infectives in wastewater using tandem solid-phase extraction and liquid chromatography-tandem mass spectrometry.

A rugged and specific method based on tandem solid-phase extraction and liquid chromatography-tandem mass spectrometry for the determination of anti-infectives in raw sewage and wastewater plant effluents was developed. Analyte recoveries from spiked effluents ranged from 68 to 104%. Two specific selected reaction monitoring transitions and their peak area ratios were used to avoid false positives and confirm the presence of the targeted substances. Detection limits allowed low nanogram per litre detection (0.3-22 ng L(-1)). The method was successfully applied to real samples from the Montréal wastewater treatment plant. All the studied anti-infectives were found in the wastewater samples in concentrations ranging from 39 to 276 ng L(-1). Mean flows of anti-infectives were estimated from effluent concentrations and it was found that large amounts (>118 g day(-1) up to 830 g day(-1)) are discharged in the receiving waters of the St Lawrence River.