Alkaline Digestion Research Articles

Recyclable hemp hurd fibre-reinforced PLA composites for 3D printing

In this study, 3D printing filaments were produced from hemp hurd fibre-reinforced polylactide (PLA) composites. Hemp hurd microfibres were obtained through alkaline digestion followed by a bleaching treatment and were used to produce PLA-based composites with 20–40 wt% fibre content for fused deposition modelling. Tensile testing of 3D printed composites revealed a gradual increase of Young's modulus with the addition of fibres, reaching a maximum of 7.1 GPa for the 40 wt% composite - a two-fold increase to neat PLA. However, tensile strength was only improved for the 20 wt% formulation, with an increase of 8% in comparison with neat PLA. Nevertheless, the thermo-mechanical properties of the composites were significantly enhanced with the addition of fibres. In addition, physical objects were printed from the recycled filaments to assess their recyclability and printability. It was found that the recycled filaments maintained comparable mechanical properties and printability after three recycling cycles.

Cost-effective Phytohormone Extraction of Sargassum swartzii from the Persian Gulf Using Magnetic Ionic Liquid.

Algae extracts are utilized as biofertilizers instead of chemical ferti-lizers in agriculture. Further, algae are known to possess a high content of plant hormones, such as gibberellin, salicylic acid, abscisic acid, and brassinosteroids. The main objective of this study was to increase the extraction yield and simulta-neously extract hormones required for plant growth from Sargassum swartzii using Magnetic recoverable ionic liquid (IL). In this study, extraction was performed by acidic digestion with acetic acid and then alkaline digestion with potassium hydroxide. The results showed the ionic liquid effect in extraction yield by 266 percent. The extracted phytohormones were analyzed using high-performance liquid chromatography (HPLC) methods. High levels of gibberellin, salicylic acid, abscisic acid, and brassinosteroids in improved algae extraction showed that seaweed extract could be used as environmentally friendly liquid bio-fertilizers to replace chemical fertilizers and could play a crucial role in organic farming for sustainable agriculture. Additionally, the recoverability of ionic liquid eight times with negligible leaching proved the introduced procedure to be cost-effective. The reported procedure for algae extraction improved by using an acidic/primary ionic liquid environment. This procedure is economical because of the simple reusability of ionic liquid due to its magnetic features.

Bactericidal activity of silver nanoparticles: An analytical approach based on single cell and single particle inductively coupled plasma mass spectrometry analysis to determine silver species involved

The bactericidal activity of silver nanoparticles is supported by a large number of studies, but their action mechanisms are still a controversial issue due to the role of the silver (I) released from the nanoparticles. In this study, direct analytical methods for detection and identification of dissolved and nanoparticulate silver based on single cell and single particle inductively coupled plasma mass spectrometry (ICP-MS) and hydrodynamic chromatography ICP-MS, in combination with alkaline digestions, have been used. Detection of silver species in Escherichia coli bacteria exposed to silver allowed to confirm the different bactericidal activity associated with silver nanoparticles of different sizes. In the case of 10 nm silver nanoparticles, a combined ion-particle action would be responsible for bactericidal effect, since ionic silver was not detected in the culture medium and both dissolved and particulate silver were detected in the exposed bacteria. On the other hand, bacteria did not internalize 60 nm silver nanoparticles and their bactericidal activity was related to the ionic silver released in the culture medium.

Techno-economic and environmental assessment of dietary fibre extraction from soybean hulls

This research evaluates the economic and environmental feasibility of extracting dietary fibre (DF) from a by-product such as soybean hulls. Techno-economic (TEA) and life cycle assessment (LCA) were carried out to identify the critical factors that may limit the implementation of a potential biorefinery plant. The modelling of the process was carried out on the basis of mass and energy balances, as well as the characteristics of the required equipment. TEA indicators such as minimum selling price (MSP), fixed capital investment, manufacturing costs were evaluated. A cradle-to-gate LCA approach and a functional unit (FU) of 1 kg of product (85% DF content) were considered. Impact categories such as global warming (GW), eutrophication, eco-toxicity, among others, were analysed. The results indicate that the production capacity achieves the plateau at about 56 kt y−1, with an MSP value of 2.6 $·kg−1. Furthermore, the GW profile was 8.76 kg CO2eq per FU, and the main hotspot is the alkaline digestion stage due to the use of potassium hydroxide (KOH). Nevertheless, the management of the hulls from multi-product food plants and switching KOH production to renewable sources may reduce the profile in almost all categories analysed.

First Approach for Defining an Analytical Protocol for the Determination of Microplastics in Cheese Using Pyrolysis–Gas Chromatography–Mass Spectrometry

The exposure of humans to microplastics through food is a topic of great interest. Foods of marine origin, such as fish and salt, have been the most extensively studied in this regard. Conversely, foods considered less likely to be contaminated (such as dairy products) have been investigated to a lesser extent. This is the first study addressing the occurrence of microplastics in cheese. In this paper, we report the first analytical approach for cheese preparation, before a chemical analysis of microplastics in cheese was performed. Therefore, the most suitable digestion methods were investigated. Alkaline digestion (i.e., KOH 5 M, 50 °C, 48 h) achieved a digestion efficiency of 97.5 ± 0.8%. To assess the feasibility of the preparative method proposed, a recovery rate of spiked polystyrene microbeads (~10 µm) of 98.5 ± 0.4% was determined. Further, the effects of the digestion agent on the microbeads were also investigated. To confirm whether the preparative method allows for the confirmation of the plastic-nature of microparticles, a qualification of spiked microplastics (polystyrene, 150 µm, and polyethylene terephthalate, 300 µm) was performed using pyrolysis–gas chromatography–mass spectrometry.

Efficacy of chemical digestion methods to reveal undamaged microplastics from planktonic samples

Standardisation and validation of methods for microplastics research is essential. A major methodological challenge is the removal of planktonic organisms from marine water samples allowing for the identification of microplastics associated to planktonic communities. To improve the reproducibility and accuracy of digestion methods for the removal of planktonic biomass, we compared and modified existing chemical digestion methods. These digestion methods included an acidic digestion using nitric acid, alkaline digestions with potassium hydroxide (alkaline 1 digestion) and sodium hydroxide from drain cleaner (alkaline 2 digestion), an oxidative digestion using sodium dodecyl sulfate with hydrogen peroxide, and an enzymatic digestion using enzyme drain clean pellets. Chemical digestion of three densities of zooplankton communities (high, medium, and low) in the presence of five commonly found environmental microplastic pollutants (polyamide, polyethylene, polyethylene terephthalate, polypropylene, and polystyrene) were performed for each treatment. The chemical treatments were assessed for (i) their digestion efficiency of zooplankton communities by different biomass densities, and (ii) their impact on microplastic particles through the comparison of both chemical (Raman spectroscopy) and physical (length, width, and visual) changes, between the pre-treatment and post-treatment microplastic particles. The alkaline 1, alkaline 2 and oxidative methods demonstrated significantly better digestion efficiency (p < 0.05) than the modified enzymatic and acidic treatments. The acidic, alkaline 1, and alkaline 2, treatments caused the most damages to the microplastic particles. We suggest future studies to implement the oxidative digestion method with sodium dodecyl sulfate and hydrogen peroxide because of its high digestion efficiency, and low damage to microplastic particles. This method is similar to the wet peroxide oxidation digestion method used throughout the literature but can be implemented at a lower cost.

LC-MS/MS quantification of olanzapine in hair after alkaline digestion.

Olanzapine (OLZ), a second-generation antipsychotic drug, is effective in the treatment of acute psychosis, schizophrenia, agitation, bipolar mania, and other psychiatric problems. Antipsychotics are prescribed drugs, which lead the drug abuser to illegal methods of access. This behavior also demonstrates the association of OLZ with criminal involvement, commonly observed at forensic crime scenes. The acute toxicity and even death resulting from OLZ exposure have been highlighted in numerous studies. Therefore, developing analytical techniques to detect OLZ is essential for forensic toxicology. This study aimed to develop a specific and reliable LC-MS/MS method for OLZ detection and quantification in hair samples. The method was validated in terms of selectivity, linearity, limit of detection (LOD), limit of quantification (LOQ), trueness, precision, and uncertainty. The range of linearity was between 0.1-100 ng/mg, with LOD and LOQ values established at 0.036 ng/mg and 0.1ng/mg, respectively. All validation results are within acceptable parameters. The validated method has been applied to authentic hair samples. The variation of OLZ concentrations in 12 hair segments (2 from Case 1 and 10 from Case 2) from two drug-positive patients, ranging from 0.131 to 0.460 ng/mg, is presented in this study. Although several studies have been conducted to determine OLZ in hair samples using segmental analysis via hair solubilization, this study is the first to determine OLZ in hair samples after "digestion" with comparative parameters prior to chromatographic analysis.

¬Occurrence of Microplastic Ingestion by Commercial Fish Species from the Pangempang Estuary in Indonesia

The aim of this study was to assess the occurrence of microplastic in digestive organs (esophagus to intestine) of popular marine commercial fish species: Jack (Caranx SP.), blackspot snapper (Lutjanus fulviflamma), coral grouper (Epinephelus carallicala), golden snapper (Lutjanus johnii) and pickhandle barracuda (Sphyraena jello) from Pangempang Estuary in Indonesia. To separate the microplastic particles, each sample was digested using alkaline digestion solution, filtered on Whatman paper and then dried. Microplastic particles in the processed digestive organ contents were identified and enumerated using a dissecting stereo microscope. Microplastics were observed in 94 % of fish digestive organs sampled: 100 % jacks (n = 10), 80 % blackspot snapper (n = 10), 100 % coral grouper (n = 10), 90 % golden snapper (n = 10) and 100 % pickhandle barracuda (n = 10). In these fish samples we found in average of 41 ± 6.0, 26 ± 11.0, 15 ± 2.0, 11 ± 1.0 and 14 ± 2.0 SE microplastic particles per individual and an average of 499.5 ± 94.4, 501.5 ± 198.8, 83.6 ± 18.4, 79.8 ± 11.6 and 40.2 ± 25.0 SE microplastic particles per kg fish weight, in jacks, blackspot snapper, coral grouper, golden snapper and pickhandle barracuda, respectively. Fiber was the most dominant type accounting for 78.6 % of all observed microplastics. Microplastic beads were not detected. The correlation of the average consumed microplastic and the average fish weight per species showed a negative relationship (R2 = 0.36), but was not significant (p-value = 0.28). Our finding suggests that demersal fish like jacks, blackspot snapper and coral grouper may have ingested a higher quantity of microplastic particles compared to pelagic species like pickhandle barracuda. HIGHLIGHTS This study demonstrates the presence of microplastic particles in 5 commercially important fish in a tropical estuary of Kalimantan Island in Indonesia Fiber was the most dominant type of microplastic Demersal fish may have ingested a higher quantity of microplastic particles compared to pelagic species GRAPHICAL ABSTRACT

Maximizing the Processing of Polymetallic Concentrates via Actinide Separation and Rare Earth Retrieval

During the last decades, the growing demand for rare earth elements (REEs) has led to numerous recent studies to recover these elements from various bearing ores and wastes. Therefore, the recovery of REEs from Ras Baroud polymetallic concentrate has been investigated in the current study. Physical beneficiation for the Ras Baroud pegmatite sample was carried out, yielding a concentrate for euxenite (Y), fergusonite (Y), xenotime (Y), monazite (Ce), allanite, thorite, uranothorite, and Hf-zircon, which resulted in raising the concentrations of rare earth elements, Th, Zr, U, and Ti in the sample. Fusion digestion processes with sodium hydroxide were studied using the Conceived Predictive Diagonal (CPD) technique. The three experimental digestion groups proved the dissolution of 99.9, 95.6, 99.9, 52.5, and 0.47% for REEs, Th, U, Ti, and Zr, respectively, under fusion conditions of 723 K, 120 min, 1/1.5 ore/alkali ratio, and − 100-μm particle sizes. Fusion kinetics, isotherms, and thermodynamics were investigated using several suggested models, namely, pseudo reversible first order, uptake general model, and shrinking core model which matched well with the experimental digestion results. Selective recovery of actinide content from REE content of the digested concentrate chloride solutions was accomplished using solvent extraction with di-2-ethyl hexyl phosphoric acid. About 99.9, 99.9, and 4.2% extraction efficiencies for Th, U, and REEs were performed, respectively, using 0.3 mol/L solvent concentration in kerosene as a diluent, 1/2 organic to aqueous ratio, an aqueous pH of 0.2, and 15-min contact time. Thorium and uranium ions were stripped with sulfuric acid solution 2.5 mol/L with 94 and 98% stripping efficiency, respectively. A highly purified REE precipitate was obtained from the raffinate solutions. Zircon mineralization tailings were obtained as a by-product through the alkaline digestion process.

Starch Extraction Methods in Tubers and Roots: A Systematic Review

Starch extraction from tubers and roots has long been an essential process, playing a crucial role in diverse industries ranging from alimentary to pharmacology. This review explores the different methods employed in starch extraction, including traditional techniques and the most innovative mechanical strategies. The methods show a good improvement in many aspects, such as an improvement in the efficiency of the process and an improvement in the yield, showing a value of 10.0–65.0% depending on the starch source. On the other hand, solvents such as NaOH are used in many mechanical processes for alkaline digestion to improve the extraction time. Ethanol and K2S2O5 concentrations of 0.5% and 0.8% were used to prevent oxidation and modify some properties of the extracted starch. The use of many solvents has improved the optimization of the processes, providing the final extracted starch with more advantages and better quality. However, using enzymes such as cellulase in new and innovative ways has provided more advantages and a better efficiency and yield than the other methods. Each method has its advantages and challenges, highlighting the importance of understanding the diversity of different approaches and their impact on the yield, sustainability, environmental considerations, and quality of the extracted starch. As the world looks for more ecological approaches, this review shows the importance of critically evaluating the yield, efficiency, and environmental implications of the extraction methods, providing us with more ways of evaluating the methods used for starch extraction. The ecological impact is a crucial point when evaluating the innovation of a new extraction process, which is why methods such as ultrasound and pulsed electric-field-assisted techniques have been proposed. These methods have been presented as sustainable techniques called green technologies, offering more approaches and different advantages than the other methods. This review intends to investigate the complexities and considerations of starch extraction, providing a solid basis for decision-making regarding starch extraction. In a time where sustainability and product quality are crucial elements of industrial strategy formulation, an in-depth understanding of these methods becomes imperative to the development of responsible practices and efficiency in starch extraction.

Searching for the Achilles' Heel of Urethane Linkage-An Energetic Perspective.

A sudden increase in polyurethane (PU) production necessitates viable recycling methods for the waste generated. PU is one of the most important plastic materials with a wide range of applications; however, the stability of the urethane linkage is a major issue in chemical recycling. In this work, termination reactions of a model urethane molecule, namely methyl N-phenyl carbamate (MPCate), are investigated using G3MP2B3 composite quantum chemical method. Our main goal was to gain insights into the energetic profile of urethane bond termination and find an applicable chemical recycling method. Hydrogenation, hydrolysis, methanolysis, peroxidation, glycolysis, ammonolysis, reduction with methylamine and termination by dimethyl phosphite were explored in both gas and condensed phases. Out of these chemicals, degradation by H2, H2O2 and CH3NH2 revealed promising results with lower activation barriers and exergonic pathways, especially in water solvation. Implementing these effective PU recycling methods can also have significant economic benefits since the obtained products from the reactions are industrially relevant substances. For example, aniline and dimethyl carbonate could be reusable in polymer technologies serving as potential methods for circular economy. As further potential transformations, several ionizations of MPCate were also examined including electron capture and detachment, protonation/deprotonation and reaction with OH-. Alkaline digestion against the model urethane MPCate was found to be promising due to the relatively low activation energy. In an ideal case, the transformation of the urethane bond could be an enzymatic process; therefore, potential enzymes, such as lipoxygenase, were also considered for the catalysis of peroxidation, and lipases for methanolysis.

Characterization of microplastics in skim-milk powders

The diffusion of microplastics in the food supply chain is prompting public concern as their impact on human health is still largely unknown. The aim of this study was to qualitatively and quantitatively characterize microplastics in skim-milk powder samples (n = 16) from different European countries (n = 8) through Fourier-transform infrared microspectroscopy in attenuated total reflectance mode analysis. The present study highlights that the use of hot alkaline digestion has enabled the efficacious identification of microplastics in skim-milk powders used for cheesemaking across European countries. The adopted protocol allowed detection of 29 different types of polymeric matrices for a total of 536 plastic particles. The most abundant microplastics were polypropylene, polyethylene, polystyrene, and polyethylene terephthalate. Microplastics were found in skim-milk powders in 3 different shapes (fiber, sphere, and irregular fragments) and 6 different colors (black, blue, brown, fuchsia, green, and gray). Results demonstrate the presence of microplastics in all skim-milk powder samples, suggesting a general contamination. Results of the present study will help to evaluate the impact of microplastics intake on human health.

Glycated Walnut Meal Peptide-Calcium Chelates: Preparation, Characterization, and Stability.

Finding stable and bioavailable calcium supplements is crucial for addressing calcium deficiency. In this study, glycated peptide-calcium chelates (WMPHs-COS-Ca) were prepared from walnut meal protein hydrolysates (WMPHs) and chitosan oligosaccharides (COSs) through the Maillard reaction, and the structural properties and stability of the WMPHs-COS-Ca were characterized. The results showed that WMPHs and COSs exhibited high binding affinities, with a glycation degree of 64.82%. After glycation, Asp, Lys, and Arg decreased by 2.07%, 0.46%, and 1.06%, respectively, which indicated that these three amino acids are involved in the Maillard reaction. In addition, compared with the WMPHs, the emulsifying ability and emulsion stability of the WMPHs-COS increased by 10.16 mg2/g and 52.73 min, respectively, suggesting that WMPHs-COS have better processing characteristics. After chelation with calcium ions, the calcium chelation rate of peptides with molecular weights less than 1 kDa was the highest (64.88%), and the optimized preparation conditions were 5:1 w/w for WMPH-COS/CaCl2s, with a temperature of 50 °C, a chelation time of 50 min, and a pH of 7.0. Scanning electron microscopy showed that the "bridging role" of WMPHs-COS changed to a loose structure. UV-vis spectroscopy and Fourier transform infrared spectrometry results indicated that the amino nitrogen atoms, carboxyl oxygen atoms, and carbon oxygen atoms in WMPHs-COS chelated with calcium ions, forming WMPHs-COS-Ca. Moreover, WMPHs-COS-Ca was relatively stable at high temperatures and under acidic and alkaline environmental and digestion conditions in the gastrointestinal tract, indicating that WMPHs-COS-Ca have a greater degree of bioavailability.

There's Something in What We Eat: An Overview on the Extraction Techniques and Chromatographic Analysis for PFAS Identification in Agri-Food Products.

Per- and polyfluorinated alkyl substances (PFASs) are a group of anthropogenic chemicals used in a range of industrial processes and consumer products. Recently, their ubiquitous presence in the environment as well as their toxicological effects in humans have gained relevant attention. Although the occurrence of PFASs is widely investigated in scientific community, the standardization of analytical method for all matrices still remains an important issue. In this review, we discussed extraction and detection methods in depth to evaluate the best procedures of PFAS identification in terms of analytical parameters (e.g., limits of detection (LODs), limits of quantification (LOQs), recoveries). Extraction approaches based on liquid-liquid extraction (LLE), alkaline digestion, and solid phase extraction (SPE), followed by liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS) analysis are the main analytical methods applied in the literature. The results showed detectable recoveries of PFOA and PFOS in meat, milk, vegetables, eggs products (90.6-101.2% and of 89.2-98.4%), and fish (96-108%). Furthermore, the low LOD and LOQ values obtained for meat (0.00592-0.01907 ng g-1; 0.050 ng g-1), milk (0.003-0.009 ng g-1; 0.010-0.027 ng g-1), fruit (0.002-0.009 ng g-1; 0.006-0.024 ng g-1), and fish (0.00369-0.017.33 ng g-1; 0.05 ng g-1) also confirmed the effectiveness of the recent quick, easy, cheap, effective, rugged, and safe method (QuEChERS) for simple, speedy, and sensitive ultra-trace PFAS analysis.

Assessment of functional efficacy of sheep plasma protein hydrolysates and their utilization in mutton sausage

The present study examines the bioactive potential of sheep plasma protein hydrolysates (SPPH) produced by in-vitro gastrointestinal digestion as antioxidants, antimicrobials, anti-obesity agents, and inhibitors of lipid oxidation in sausage to address the oxidative stability and shelf-life issues of mutton. The antioxidant and antimicrobial activities, indicate a positive relationship between the degree of hydrolysis and digestion duration. The study finds that SPPH has a potent inhibitory effect on pancreatic lipase and cholesterol esterase. It has higher oil holding capacity than sheep plasma protein, observed at one hour of hydrolysis time. SPPH exhibit an improved behavior in foaming properties along alkaline pH and digestion time while display lower emulsifying activity and stability with hydrolysis advancement. The SPPH act as a natural preservative in developing functional mutton sausage by inhibiting lipid-oxidation. This study showed that the recovery of SPPH can be a cost-effective and sustainable strategy for generating available ingredients for enhanced shelf-life of meat products.

Coproduction of silicon nitride & oxynitride whiskers and precipitated silica from industrial rice husk ash

Rice industrialization generates large amounts of rice husk, and when this husk is burned, substantial volumes of ash are produced as a result. The lack of a sustainable application for these ashes constitutes a serious environmental liability. Employing rice husk ash as a starting material to manufacture higher-value products fulfills both environmental and economical purposes. Particularly, the presence of silica and carbon in intimate contact makes rice husk ash an attractive precursor for carbothermal reduction and nitridation processes. In the present work, a pre-treatment was applied to a locally sourced industrial rice husk ash, aiming to render not only a more appropriate starting material for carbothermal reduction and nitridation, but also precipitated silica as a by-product. This process involved a simple alkaline digestion step followed by filtering and acid precipitation of the solubilized silica. For carbothermal reduction and nitridation, the treated ash was introduced in graphite crucibles with graphite lids and held at soaking temperatures between 1200 °C and 1400 °C under a nitrogen atmosphere for 3 h. The pretreatment imposed on the ash permitted the adjustment of the carbon-to-silica ratio, producing a substantial improvement in the carbothermal reduction and nitridation results, and enabling the simultaneous obtention of precipitated silica. α- and β- silicon nitride, and silicon oxynitride whiskers were obtained through carbothermal reduction and nitridation of the treated rice husk ash. The whiskers obtained had lengths in the millimeter range with cross-sections ranging from about 100 nm up to 500 nm.

Valorising Cassava Peel Waste Into Plasticized Polyhydroxyalkanoates Blended with Polycaprolactone with Controllable Thermal and Mechanical Properties

Approximately 99% of plastics produced worldwide were produced by the petrochemical industry in 2019 and it is predicted that plastic consumption may double between 2023 and 2050. The use of biodegradable bioplastics represents an alternative solution to petroleum-based plastics. However, the production cost of biopolymers hinders their real-world use. The use of waste biomass as a primary carbon source for biopolymers may enable a cost-effective production of bioplastics whilst providing a solution to waste management towards a carbon–neutral and circular plastics economy. Here, we report for the first time the production of poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) with a controlled molar ratio of 2:1 3-hydroxybutyrate:3-hydroxvalerate (3HB:3HV) through an integrated pre-treatment and fermentation process followed by alkaline digestion of cassava peel waste, a renewable low-cost substrate, through Cupriavidus necator biotransformation. PHBV was subsequently melt blended with a biodegradable polymer, polycaprolactone (PCL), whereby the 30:70 (mol%) PHBV:PCL blend exhibited an excellent balance of mechanical properties and higher degradation temperatures than PHBV alone, thus providing enhanced stability and controllable properties. This work represents a potential environmental solution to waste management that can benefit cassava processing industries (or other crop processing industries) whilst developing new bioplastic materials that can be applied, for example, to packaging and biomedical engineering.Graphical

The neutralization of tricalcium aluminate hexahydrate and its spontaneous transformation into Friedel's salt, a layered double hydroxide

Tricalcium aluminate hexahydrate, C3AH6, forms during the hydration of the oxide form, C3A. Modelling the resulting phase composition over time has been the subject of intensive research; yet, understanding the effect of pH, a crucial parameter of cementitious mixtures, has remained elusive. To this end, we studied the stability of C3AH6 in a wide pH range via the addition of HCl. We compared the behavior of conventional ‘cement’ C3AH6 and ‘Bayer’ C3AH6, synthesized via alkaline digestion. Upon addition of HCl to mixtures in H2O or NaCl, both phases slowly transform in an equilibrium reaction into Friedel's salt, C4ACl2H10, a layered double hydroxide (LDH) with chloride ions being intercalated between the layers. Consequently, C3AH6, C4ACl2H10, and Al(OH)3 are likely to coexist in the pH range of 11–12. Furthermore, we find the reverse process, i.e. C4ACl2H10 → C3AH6 to be kinetically hindered, consistent with the high stability of C4ACl2H10 compared to hydroxide-intercalated LDHs.

Rapid detection and identification of microplastics from nonchemically treated soil with CARS microspectroscopy

In conventional microplastic (MP) analysis, acid or alkaline digestion is a necessary pretreatment step to remove residual organic matter from environmental samples. However, such a digestion process is not only cumbersome and time-consuming, but also possibly cause severe chemical damage to the MP itself, often making accurate MP characterization difficult. This study demonstrates that broadband coherent anti-Stokes Raman scattering (CARS) microspectroscopy is useful for rapidly detecting and identifying MPs in natural soil without any digestion process. A feasibility test is performed with soil samples, which are known to require the most complicated chemical pretreatment for MP analysis, deliberately mixed with various MP particles. The C–H bond-specific CARS imaging and spectral analysis allow rapid MP particle search and chemical identification even in the presence of other residual particles and strongly fluorescent substances from the soil. It is anticipated that this nondestructive, chemical pretreatment-free CARS approach will be a beneficial tool for studying the ecological impacts of MPs absorbed by terrestrial life, such as plants and soil organisms, as well as for complementary analysis of MPs subject to chemical degradation by digestion in investigating the environmental contamination of the MPs.

BIOM-26. RAPID IDENTIFICATION OF IDH1-R132 VARIANTS IN GLIOMA WITH LOCKED NUCLEIC ACID LOOP-MEDIATED ISOTHERMAL AMPLIFICATION (LNA-LAMP)

Abstract Point mutations that impact the catalytic site of isocitrate dehydrogenase 1 (IDH1) are associated with an extended overall survival of approximately 3.8 years for glioma patients compared to 1 year for those with wild-type IDH1. The difference in survival benefit is associated with the maximal surgical resection of IDH1 mutant tumors, making intraoperative knowledge of the mutational status valuable. Unfortunately, current methods used to determine IDH1-R132 mutational status are incompatible with obtaining real-time results. We have developed a panel of assays that use LNA-LAMP to identify commonly encountered IDH1-R132 variants (R132H, R132C, R132G, R132S, R132L) within 40 minutes. These assays require little preanalytical processing, no complex equipment, and yield results which are easily interpreted by the naked eye. Tumor samples are initially subjected to a 5-minute alkaline digest, then added directly to LNA-LAMP reactions containing primers unique to each IDH1-R132 variant. Discrimination between the wild-type and mutant allele is achieved with the integration of locked nucleic acids within primers. A reaction with an IDH1-R132R specific primer serves as the sample positive control, as all tumor lysates are expected to contain wild-type IDH1 DNA. Lysates are incubated for 35 minutes in a hot water bath, followed by visual interpretation using a pH-based colorimetric indicator, where samples positive for the mutation appear a vibrant yellow while those lacking the mutation remain pink. This method has been rigorously tested with patient-derived tumor lysates, yielding reproducible and accurate results, and has an analytical sensitivity of about 20% mutant DNA in a background of wild-type DNA. This sensitivity is comparable to that of Sanger Sequencing while simultaneously offering a more cost-effective and efficient workflow. LNA-LAMP is amenable for use in the intraoperative window to allow patients with an IDH1-R132 mutation the benefit of a maximal surgical resection.