Plastic Samples Research Articles

Unprecedented marine microplastic contamination from the X-Press Pearl container vessel disaster

The objectives of the research was to assess the coastal pollution by plastic nurdles, pyrolitic debris, associated potential toxic elements (PTEs) concentrations and mitigatory efforts by the worst ever maritime accident of a chemical and plastic boarded container vessel; MV X-Press Pearl. Field sampling was carried out three times during May, June, and September 2021 at Sarakkuwa, Sri Lanka. Pellet pollution index (PPI) was determined to compare the degree of plastics pollution. Density separation (NaCl) followed by wet peroxide digestion for plastic separation and characterized by Fourier transform infrared spectroscopic, thermo gravimetric analysis and differential scanning calorimetric analysis. Sand and plastics samples were digested and analyzed for PTEs (Li, Mo, Cr, Pb, and Cu), are suspect to mix during disaster. Identified debris were mostly confirmed as low-density polyethylene, epoxy resins, olefin copolymers, aromatic polyamides, natural rubber, and polyethylene terephthalate. Sulfur contamination and physical erosion were observed in nurdles received in June and September. Calculated PPIs were ‘high’ for Sarakkuwa beach even in September with a very high pellet pollution degree (10.24 pellets per m2) compared to the control obtained from the same site in 2020 (1.6 pellets per m2). Input sand for the blue treatment facility was found as the extremely contaminated with Mo and Li with 239.71 and 1.69 mg/kg respectively other than microplastics. Blue treatment facility seemed effective in physical separation of microplastics from sand, however, it is an exhausting process due to continuous receive of microplastics from the waves and excavation of sea shore.

The lanolin‐based oil plasticized polylactide: Thermal and chemical characteristics

AbstractBio‐based plasticizers are a significant replacement for petrochemical‐based plasticizers because they are from renewable resources. The plasticizing effect of lanolin‐based oil at a different concentration and as an additive on polylactide's thermal and chemical stability (PLA) was investigated. The thermal stability was assessed using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The plasticized PLA samples were also analyzed with a dynamic mechanical analyzer (DMA), X‐ray powder diffraction (powder XRD), and infrared (IR) spectroscopy. The plasticizer modified the thermal stability of the PLA polymer by increasing the cold crystallization temperature (Tcc), as shown by DSC. At the same time, the DMA data indicated a reduction in the dynamic storage modulus and glass transition temperature (Tg) with increased amounts of plasticizer content. The powder X‐ray diffraction patterns showed that the PLA has no polymorphic crystalline transition with the oil plasticizer. The analysis from the results shows the oil additive's potential as a bio‐based plasticizer for PLA However, further performance improvements are required for large‐scale production. From the results obtained, there are enhancements in the thermal and physical properties of the modified PLA, and it is suitable for composite production.

Numerical Simulation on the Acoustic Streaming Driven Mixing in Ultrasonic Plasticizing of Thermoplastic Polymers.

The acoustic melt stream velocity field, total force, and trajectory of fluorescent particles in the plasticizing chamber were analyzed using finite element simulation to investigate the acoustic streaming and mixing characteristics in ultrasonic plasticization micro-injection molding (UPMIM). The fluorescence intensity of ultrasonic plasticized samples containing thermoplastic polymer powders and fluorescent particles was used to determine the correlation between UPMIM process parameters and melt mixing characteristics. The results confirm that the acoustic streaming driven mixing occurs in ultrasonic plasticization and could provide similar shear stirring performance as the screw in traditional extrusion/injection molding. It was found that ultrasonic vibrations can cause several melt vortices to develop in the plasticizing chamber, with the melt rotating around the center of the vortex. With increasing ultrasonic amplitude, the melt stream velocity was shown to increase while retaining the trace, which could be altered by modulating other parameters. The fluorescent particles are subjected to a two-order-of-magnitude stronger Stokes drag force than the acoustic radiation force. The average fluorescence intensity was found to be adversely related to the distance from the sonotrodes’ end surface, and fluorescence particles were more equally distributed at higher parameter levels.

Baseline study of trace metal concentrations in abandoned, lost or otherwise discarded fishing gear along Thondi coast, Palk Bay, India

The Abandoned, Lost or otherwise Discarded Fishing Gear (ALDFG) are commonly found in the ocean these days due to the negligence of the fishermen. The present study aims to identify the discarded fishing gear sample and determine metals' absorption rate by ALDFGs. The identification of the ALDFG was done with the help of ATR-FTIR in which it was confirmed that the samples are mostly made of nylon 6. Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR) peaks such as 3435.43 cm−1, 2926.38 cm −1, 2857.74 cm−1 correspond to nylon 6. Adsorption of trace metals by Inductively Coupled Plasma-Mass Spectroscopy (ICP-MS) confirmed the presence of elements such as Aluminium, Barium, Cadmium, Calcium, Chromium, Cobalt, Copper, Iron, Lead, Magnesium, Manganese, Nickel, Phosphorus, Potassium, Rubidium, Sodium, Strontium, Vanadium and Zinc in the identified plastic sample. The Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy (SEM-EDX) micrographs were confirmed the adsorption of elements by the surface of the sample and revealed the level of adsorption of trace metals in the abandoned, lost or otherwise discarded fishing gear.

Use of the FRP plates instead of steel sheets in the joints of wooden structures

The use of steel plates in the joints of wooden structures is a common practice. However, because of the presence of natural moisture in the wood, steel sheets are easily corroded, and for this reason, the wood near the joints decays over time and thus, shortens the life of wooden structures. This study examines the feasibility of using noncorrosive fibre reinforced plastics (FRP) instead of steel plates applied in different joint areas of wooden structures, in terms of mechanical strength. In the study, six samples were tested with five different joint types, four different materials and two different experiments. As a result, it was found that besides many physical advantages of FRP, the strength of the carbon fibre reinforced plastic samples exceeded that of the samples reinforced with steel sheets by 50%, and the strength of the glass fibre reinforced plastic samples reached 70% of the strength of samples reinforced with steel sheets.

Distribution and possible sources of atmospheric microplastic deposition in a valley basin city (Lanzhou, China)

The deposition is an important process of microplastics transporting from atmosphere to water and soil. But the spatial and temporal distribution of microplastics in urban atmospheric deposition and its influencing factors are poorly understood. The current study investigated the possible sources, spatial and temporal distribution, and potential ecological risk of microplastics in deposition from the valley basin of Lanzhou city during the COVID-19 pandemic (from February to August, 2020). The deposition flux of microplastics was 353.83 n m−2 d−1. Most plastic samples were small sized (50～500 µm) and transparent. The dominant chemical composition and shapes were PET, fragments and fibers, respectively. A modified method was conducted to identify the sources of microplastics, and the local sources were suggested as the main possible sources. The distribution of microplastics investigated through the inverse distance weight interpolation showed spatial variation and temporal differentiation which was dominated by the human activity. The rainfall also affected the temporal distribution. The preliminary assessment indicated higher potential ecological risk of microplastics in deposition. This study suggested the dominant effect of human activity on the source and distribution of atmospheric microplastic deposition in city.

β-Ketoenamine-linked covalent organic framework absorbent for online micro-solid phase extraction of trace levels bisphenols in plastic samples.

Covalent organic frameworks with tunable porous crystallinity and outstanding stability have exhibited fascinating pretreatment performance as ideal extraction media. Herein, the β-ketoenamine-linked TpPa-1 synthesized by 1,3,5-triformylphloroglucinol and paraphenylenediamine was employed as the absorbent for online micro-solid phase extraction of trace bisphenols combined with high-performance liquid chromatography detection. A series of characterizations indicated that the TpPa-1 possessed large surface areas, high stability, and hydrophobicity. The main experimental parameters affecting the extraction efficiency were optimized in detail. Compared with four commercial sorbents, the TpPa-1 exhibited superior enrichment capacity for extracting bisphenols. Under the optimum conditions, the established method demonstrated a wide linear range and high sensitivity with the limit of detection ranging from 0.05-0.06 μg/L. Furthermore, the developed method was successfully applied to determine bisphenols in plastic samples. Bisphenol A was actually detected in a transparent box with a concentration of 0.31 μg/g, and the recoveries of the four bisphenols in the plastic samples were 80.5-116% with the relative standard deviation less than 9.2%. Such performance was attributed to recognition affinity, including the π-π affinity, hydrophobic effect, and hydrogen bond. These results demonstrated that TpPa-1 possessed great potential to be an excellent pretreatment medium for online separation and analysis of trace analytes in complex samples.

Extending Effective Dynamic Range of Hyperspectral Line Cameras for Short Wave Infrared Imaging.

In this work, a multi-exposure method is proposed to increase the dynamic range (DR) of hyperspectral imaging using an InGaAs-based short-wave infrared (SWIR) hyperspectral line camera. Spectral signatures of materials were captured for scenarios in which the DR of a scene was greater than the DR of a line camera. To demonstrate the problem and test the proposed multi-exposure method, plastic detection in food waste and polymer sorting were chosen as the test application cases. The DR of the hyperspectral camera and the test samples were calculated experimentally. A multi-exposure method is proposed to create high-dynamic-range (HDR) images of food waste and plastic samples. Using the proposed method, the DR of SWIR imaging was increased from 43 dB to 73 dB, with the lowest allowable signal-to-noise ratio (SNR) set to 20 dB. Principal Component Analysis (PCA) was performed on both HDR and non-HDR image data from each test case to prepare the training and testing data sets. Finally, two support vector machine (SVM) classifiers were trained for each test case to compare the classification performance of the proposed multi-exposure HDR method against the single-exposure non-HDR method. The HDR method was found to outperform the non-HDR method in both test cases, with the classification accuracies of 98% and 90% respectively, for the food waste classification, and with 95% and 35% for the polymer classification.

Investigating Antimicrobial Characteristics/Advantages of Australian Wood Species for Use in Food Packaging—A Feasibility Study

The antimicrobial characteristics of Australian commercial timber species were studied using a direct screening method and two different microorganisms. The effectiveness of timber samples was compared with plastic and paper samples during an incubation period of 24 h at 37 °C. The initial data with E. coli and S. aureus showed no difference in performance between the plastic and paper samples and the softwood samples tested. Hardwood samples, however, showed an inhibition zone when tested with S. Aureus. The data showed similar trends of inhibition zones developed for sterilised and non-sterilised samples of spotted gum and shining gum species. The observed data showed promising antimicrobial characteristics for both veneer and solid samples of hardwood species. Further studies investigating the type of extractives, their role in antimicrobial characteristics and differences in the type of surface exposed to the microbial contamination from the point of view of timber’s anatomical properties are proposed.

Polarization Sensitive Imaging with Qubits

We compare reconstructed quantum state images of a birefringent sample using direct quantum state tomography and inverse numerical optimization technique. Qubits are used to characterize birefringence in a flat transparent plastic sample by means of polarization sensitive measurement using density matrices of two-level quantum entangled photons. Pairs of entangled photons are generated in a type-II nonlinear crystal. About half of the generated photons interact with a birefringent sample, and coincidence counts are recorded. Coincidence rates of entangled photons are measured for a set of sixteen polarization states. Tomographic and inverse numerical techniques are used to reconstruct the density matrix, the degree of entanglement, and concurrence for each pixel of the investigated sample. An inverse numerical optimization technique is used to obtain a density matrix from measured coincidence counts with the maximum probability. Presented results highlight the experimental noise reduction, greater density matrix estimation, and overall image enhancement. The outcome of the entanglement distillation through projective measurements is a superposition of Bell states with different amplitudes. These changes are used to characterize the birefringence of a 3M tape. Well-defined concurrence and entanglement images of the birefringence are presented. Our results show that inverse numerical techniques improve overall image quality and detail resolution. The technique described in this work has many potential applications.

Evolution of prokaryotic colonisation of greenhouse plastics discarded into the environment

Current knowledge on the capacity of plastics as vectors of microorganisms and their ability to transfer microorganisms between different habitats (i.e. air, soil and river) is limited. The objective of this study was to characterise the evolution of the bacterial community adhered to environmental plastics [low-density polyethylene (LDPE)] across different environments from their point of use to their receiving environment destination in the sea. The study took place in a typical Mediterranean intermittent river basin in Larnaka, Cyprus, characterised by a large greenhouse area whose plastic debris may end up in the sea due to mismanagement. Five locations were selected to represent the environmental fate of greenhouse plastics from their use, through their abandonment in soil and subsequent transport to the river and the sea, taking samples of plastics and the surrounding environments (soil and water). The bacterial community associated with each sample was studied by 16S rRNA metabarcoding; also, the main physicochemical parameters in each environmental compartment were analysed to understand these changes. The identification and chemical changes in greenhouse plastics were tracked using Attenuated Total Reflection Fourier Transform Infra-red spectroscopy (ATR-FTIR). Scanning Electron Microscope (SEM) analysis demonstrated an evolution of the biofilm at each sampling location. β-diversity studies showed that the bacterial community adhered to plastics was significantly different from that of the surrounding environment only in samples taken from aqueous environments (freshwater and sea) (p-value p-value > 0.05). The environmental parameters (pH, salinity, total nitrogen and total phosphorus) explained the differences observed at each location to a limited extent. Furthermore, bacterial community differences among samples were lower in plastics collected from the soil than in plastics taken from rivers and seawater. Six genera (Flavobacterium, Altererythrobacter, Acinetobacter, Pleurocapsa, Georgfuchsia and Rhodococcus) were detected in the plastic, irrespective of the sampling location, confirming that greenhouse plastics can act as possible vectors of microorganisms between different environments: from their point of use, through a river system to the final coastal receiving environment. In conclusion, this study confirms the ability of greenhouse plastics to transport bacteria, including pathogens, between different environments. Future studies should evaluate these risks by performing complete sequencing metagenomics to decipher the functions of the plastisphere.

Efficacy of carbon nanotubes and polydimethylsiloxane interlayer in augmenting the impact strength of glass fiber/epoxy composites

An experimental investigation is carried out to explore the possibility of carbon nanotubes addition and incorporation of polydimethylsiloxane soft interlayer in improving the impact strength and energy-absorbing capability of conventional glass fiber-reinforced plastics. To this end, deformation behavior of glass fiber-reinforced plastics, carbon nanotube-modified glass fiber-reinforced plastics, and glass fiber-reinforced plastics-polydimethylsiloxane sandwich coupons under high strain rate loading are compared using the split-Hopkinson pressure bar testing technique. While neat epoxy is used to process conventional glass fiber-reinforced plastics, the carbon nanotubes-modified glass fiber-reinforced plastics samples are fabricated using 0.5 wt. % carbon nanotube-modified epoxy. The split-Hopkinson pressure bar testing reveals that the addition of carbon nanotubes improves the peak stress and energy-absorbing capacity of the epoxy matrix. The improved impact response of carbon nanotube-modified epoxy translates into enhanced peak stress and energy-absorbing capability of carbon nanotubes-modified glass fiber-reinforced plastics in comparison to conventional glass fiber-reinforced plastics under impact loading. The microscopy analysis of failed composite samples reveals that while glass fiber-reinforced plastics primarily fails at the fiber/epoxy interface, the failure initiates in the epoxy matrix in carbon nanotubes-modified glass fiber-reinforced plastics samples. The impact testing of sandwich samples shows that the insertion of neat and 0.05 wt. % carbon nanotube-modified polydimethylsiloxane interlayer helps to distribute the impact load in a wider domain and thus delays the failure of glass fiber-reinforced plastics sandwich coupons. Moreover, the carbon nanotube-modified polydimethylsiloxane interlayer is better suited to increase the damage resistance and energy-absorbing ability of glass fiber-reinforced plastics. The present study provides a feasible strategy to enhance the failure strength and energy-absorbing capacity of conventional composites using carbon nanotube-modified epoxy and polydimethylsiloxane-based interlayer.

Detecting the release of plastic particles in packaged drinking water under simulated light irradiation using surface-enhanced Raman spectroscopy

Plastic cups and bottles used for mineral water packaging may release plastic particles during continuous exposure to heat, light, or unfavorable chemical environments during transportation and storage. Surface-enhanced Raman spectroscopy (SERS) can be used to detect and analyze these plastic particles in a highly sensitive and quantitative manner. In this study, we used copper oxide/silver nanoparticles (CuO/Ag NPs) as the SERS substrate to monitor the release of plastic particles in packaged mineral water samples under irradiation as a function of exposure time. The lower detection limit for plastic particles using this CuO/Ag NP SERS system was 1.6 ng/mL. Our results showed that both plastic cups and bottles released particles under irradiation, however, the plastic cup samples degraded much more readily, with the particle concentration increasing considerably from 5.37 ± 0.11 ng/mL to 3751 ± 0.19 ng/ml over the total exposure time period of 240 min. In this study, we have demonstrated that SERS can provide a highly sensitive, rapid, and economical method for detecting plastic particle contamination caused by degradation of the plastic materials used in mineral water packaging.

Removal of phthalate ester compound from PVC plastic samples using magnetic molecularly imprinted polymer on the surface of superparamagnetic Fe3O4 (Fe3O4@MIPs)

In this study, novel magnetic molecularly imprinted polymers (MMIPs) were successfully synthesized for selective separation of di(2-ethylhexyl)phthalate (DEHP) in PVC sample solutions. Polymerization was carried out using Fe3O4 modified by oleic acid, ethylene glycol dimethacrylate (EGDMA), methacrylic acid (MAA), and benzoyl peroxide (BPO) in the presence of DEHP as template molecule to produce MMIPs named Fe3O4@MIPs. Magnetic non-molecularly imprinted polymers (MNIPs) were also prepared for comparison purposes. The structure and physical properties of MMIPs and MNIPs were characterized using FT-IR, SEM, TEM, VSM and zeta potential analysis. The FT-IR spectra showed that MMIPs were successfully synthesized, indicated by the presence of a Fe-O peak at 586 cm−1, a benzene derivative peaks at 709, 1072, and 1155 cm−1, a carbonyl peak of MAA at 1728 cm−1 and a C–H peak of oleic acid at 2954 cm−1. SEM and TEM measurements showed that MMIPs were porous polymers with a smaller particle size than MNIPs. VSM measurement showed that MMIPs were superparamagnetic with a saturation magnetism value of 39.92 emu/g. MMIPs have a better adsorption capacity than MNIPs with an imprinting factor (IF) value of 3.37 and a maximum adsorption capacity value of 17.21 mg/g. The sorption studies showed that the adsorption process followed the Langmuir isotherm model and fitted well to a pseudo-second-order kinetic model with ΔHo of −82.17 kJ mol−1. Moreover, MMIPs were more selective to DEHP than dibutyl phthalate (DBP), with a selectivity coefficient value of 4.57. The desorption test showed that MMIPs showed good regeneration with a desorption percentage of 98.42% and decreasing in adsorption capacity of 11.2% after three times regenerations. DEHP removal from PVC samples using MMIP showed that polymer could reduce the matrixes effect with a recovery percentage of around 91.03–99.68%.

The effect of plastic type on the yield and quality of lignite and plastic waste pyrolysis products

Lignite is a low rank coal which has great potential in South Kalimantan. However, it has not been used optimally due to its low quality. One of the ways to improve it is pyrolysis. Pyrolysis is the thermal decomposition of organic material in the absence of oxygen which will produce three products (char, tar and gas). Pyrolysis can make lignite into liquid fuel (pyrolysis liquid), but it still requires improvement due to the need for pure hydrogen donors. Plastic waste has a higher hydrogen/carbon ratio than coal. This material can be used as an additive in the pyrolysis process because it is rich in hydrogen. The samples of plastic waste used were ppolyethylene (PE), ppolypropylene (PP), and polystyrene (PS). Samples of lignite and plastic (plastic composition was 25 wt%) were used for every experiment, and pyrolysis was carried out with a holding time of 60 minutes at 500°C. The pyrolysis liquid obtained is then analyzed for its yields and properties (density, kinematic viscosity, heating value). The most feasible result for fuel alternative was obtained with the addition of PE.

An Ultra-Sensitive Molecularly Imprinted Poly(Aniline) Based Electrochemical Sensor for the Determination of Bisphenol A in Synthetic Human Serum Specimen and Plastic Bottled Water Samples

We explain the development of an ultra-sensitive molecularly imprinted polymer-based electrochemical sensor for rapid and selective determination of bisphenol A (BPA) in human serum and water samples. Electropolymerization of functional monomer aniline was performed in the presence of BPA by cyclic voltammetry (CV) to prepare a molecularly imprinted poly(aniline) based GCE sensor (MIP(ANI)/GCE). The developed MIP surface was characterized using Fourier-transform infrared spectroscopy, Raman spectrometry, scanning electron microscopy, contact angle measurements, CV, and electrochemical impedance spectroscopy. The MIP(ANI)/GCE sensor showed a highly sensitive performance with a linear range of 1.0 and 8.0 × 10−15 M. The limit of detection (LOD) and limit of quantification (LOQ) values were 0.193 and 0.643 fM, respectively. The applicability of the MIP(ANI)/GCE was assessed by applying it to human serum and plastic bottled water samples. The LOD and LOQ values were calculated as 0.257 and 0.856 fM for the serum sample. Imprinting factor and interference studies were also carried out using similarly structured compounds and the most common interfering agents showing the selectivity of the MIP(ANI)/GCE sensor. Finally, the non-imprinted polymer (NIP)-based sensor was prepared to control the MIP(ANI)/GCE performance.

Screening of polymer types and chemical weathering in macro- and meso-plastics found on lake and river beaches using a combined chemometric approach.

In the environment, synthetic polymers, commonly known as "plastics", are well-known to undergo various chemical weathering processes, which modify their surface chemistry by introducing new functional groups. Such changes are important to monitor, as they can severely influence the toxicity caused by plastic debris. Therefore, in this study, two chemometric models are proposed to accelerate the chemical classification of macro- and meso-plastics found in the environment. For this purpose, principal component analysis (PCA) and hierarchical cluster analysis (HCA) were applied on preprocessed infrared spectra of 83 plastic fragments found on public lake and river beaches. HCA associated all beach samples with a known plastic, whereas PCA enabled the association of only 39.8% (33 out of 83) of the beach samples with a known plastic. However, both techniques agreed on 93.9% of the samples identified. According to PCA and HCA results, polypropylene and polyethylene were the most frequently identified polymers in the samples. PCA turned out to be a very promising tool for fast screening of weathered plastics, since the distance of samples from the polypropylene cluster in the PCA plot was correlated with weathering. This was later confirmed by employing other characterization techniques such as micro-Raman, X-ray photoelectron spectroscopy and scanning electron microscopy. Finally, future experiments should focus on the applicability of the proposed combined chemometric approach for very small microplastics (<100 μm), as they have more important effects than larger plastics on aquatic ecosystems.

Investigation of mechanical characteristics of braided carbon fiber

The use of composite materials in various branches of modern industry is rapidly increasing due to their high strength properties, low weight and good manufacturability. A wide variety of materials used, types of reinforcement and internal structures creates a need for studies of the static and dynamic properties of composite materials. Due to the latest advances in technology, composite materials are widely used in a variety of industrial applications. As a result, there is considerable interest in studying and understanding the behavior of composite structures. Analysis of composite structures, study of resonance frequencies, damping factors and modal shapes played an important role in determining the dynamic characteristics of the structure, detecting damage and monitoring the state of the composite structure. In this paper, the results of computational and experimental researches of the Young’s modulus, natural frequencies and modes of vibration, damping properties of the composite material are presented. The researches were carried out on samples of the woven ten-layer carbon fiber reinforced plastic. The investigated carbon fiber reinforced plastic has a plain weave. Samples were cut in three directions: warp (0 °), weft (90 °) and 45 °. Nine samples were prepared for each direction. To study the Young’s modulus, a tensile testing machine was used, and a vibration stand was used to determine the natural frequencies and modes of vibration. Damping properties are calculated by the Oberst method, based on the amplitude-frequency characteristics of the samples. Statistical processing of the experimental results was carried out and the values ​​of the mathematical expectation and variance were obtained. Geometric and finite element models of сarbon fiber reinforced plastic samples were built, their natural frequencies and vibration modes were determined. Comparison of the computational and experimental data with numerous calculations using the finite element method is carried out.

Occurrence and distribution of micro(meso)plastic-sorbed heavy metals and metalloids in sediments, Gulf of Guinea coast (SE Atlantic)

The pervasive existence of microplastics (MPs) and toxic metals is raising environmental and health concerns. Plastics are essentially a complex mixture of chemicals, but exposure to the aquatic environment increases their complexity through contaminant desorption/sorption. The aim of this study was to establish baseline data on the elemental occurrence and distribution of potentially toxic and geochemical metals/metalloids in microplastics 1–5 mm and mesoplastics (> 5 mm – 1 cm) along designated coastlines of the Gulf of Guinea (Nigeria) in addition to enabling more comprehensive ecotoxicological risk assessment. The concentrations of twenty-six metals: aluminium (Al), antimony (Sb), arsenic (As), barium (Ba), boron (B), cadmium (Cd), calcium (Ca), chromium (Cr), cobalt (Co), copper (Cu), iron (Fe), lead (Pb), magnesium (Mg), manganese (Mn), molybdenum (Mo), nickel (Ni), potassium (K), selenium (Se), sodium (Na), silicon (Si), silver (Ag), strontium (Sr), thallium (Tl), titanium (Ti), vanadium (V), and zinc (Zn), associated with beach MPs, pristine, and lagoon plastics were determined after extraction in 10% nitric acid and analysis using inductively coupled plasma-optical emission spectroscopy (ICP-OES). The distribution of MPs was variable, with 3680 particles identified along the drift and high waterlines across designated shoreline locations. The beach MPs were dominated by polyethylene (PE), polypropylene (PP), and polystyrene (PS), whereas lagoon-sourced plastics were characterized by polyethylene terephthalate (PET), polystyrene (PS), and polyurethane (PUR). Metal concentration was higher when associated with foam plastic (PS, PUR, PEVA) compared to hard plastic (PE, PP, PET) samples. The results showed that all samples had slightly elevated Al, Fe, Mn, and Zn concentrations, suggesting potential sorption interactions and plastic additive influences. Notably, foam MPs had a stronger affinity for metals. This study emphasizes the critical role of microplastics in serving as vectors for toxic metals. Except for Cd, pollution indices such as the potential contamination index (PCI), hazard quotient (HQ), and modified hazard quotient (mHQ) indicated low severity contamination of beach and lagoon MPs by heavy metals. However, considering long-term accumulation of sorbed metals, their potential toxicity to marine biota may be considerable.

Validation of N-LightTM L. monocytogenes for Detection of Listeria monocytogenes on Environmental Surfaces: AOAC Performance Tested MethodSM 122002.

The NEMIS Technologies N-LightTM L. monocytogenes assay uses chemiluminescence designed for the qualitative detection of Listeria monocytogenes from environmental surface samples. To validate the NEMIS Technologies N-Light L. monocytogenes assay as part of the AOAC Performance Tested MethodSM program for the detection of L. monocytogenes on stainless steel, plastic (polystyrene), and ceramic environmental surfaces. Using the Vitl Life Science Solutions Lu-mini luminometer, the NEMIS Technologies N-Light L. monocytogenes assay was compared to the ISO 11290-1:2017: Microbiology of the Food Chain-Horizontal method for the detection and enumeration of Listeria monocytogenes and of Listeria spp. - Part 1 using a 1" × 1" stainless steel test area in an unpaired study design. The NEMIS Technologies N-Light L. monocytogenes assay using the Vitl Life Science Solutions Lu-mini luminometer demonstrated no statistically significant differences between presumptive and confirmed results or between candidate and reference method results. Data for additional Performance Tested MethodSM studies met acceptance criteria requirements. The NEMIS Technologies N-Light L. monocytogenes assay is an effective method for the qualitative detection of L. monocytogenes from stainless steel, plastic (polystyrene), and ceramic environmental surface samples. The NEMIS method is the first chemiluminescence detection system based on a novel, patented, dioxetane compound.