Organosolv lignin aggregation behaviour of soluble lignin extract from Miscanthus x giganteus at different ethanol concentrations and its influence on the lignin esterification

Background Lignin is the second most abundant naturally occurring biopolymer from lignocellulosic biomass. While there are several lignin applications, attempts to add value to lignin are hampered by its inherent complex and heterogenous chemical structure. This work assesses the organosolv lignin aggregates behaviour of soluble lignin extract derived from Miscanthus × giganteus using different ethanol concentrations (50%, 40%, 30%, 20%, 10% and 1%). The effect of two different lignin concentrations using similar ethanol concentration on the efficacy of esterification was studied. Results Overall, particle size of lignin analysis showed that the particle size of lignin aggregates decreased with lower ethanol concentrations. 50% ethanol concentration of soluble lignin extract showed the highest particle size of lignin (3001.8 nm), while 331.7 nm of lignin particle size was recorded at 1% ethanol concentration. Such findings of particle size correlated well with the morphology of the lignin macromolecules. The lignin aggregates appeared to be disaggregated from population of large aggregates to sub-population of small aggregates when the ethanol concentration was reduced. Light microscopy images analysis by ImageJ shows that the average diameter and circularity of the corresponding lignin macromolecules differs according to different ethanol concentrations. The dispersion of lignin aggregates at low ethanol concentration resulted in high availability of hydroxyl group in the soluble lignin extract. The efficacy of the lignin modification via esterification was evidenced directly via FTIR using the similar ethanol concentration of soluble lignin extract at different lignin concentrations. Conclusion This study provided the understanding of detail analysis on particle size determination, microscopic properties and structural insights of lignin aggregates at wider ethanol concentrations. The esterified lignin derived at 5 mg/mL is suggested to expand greater lignin functionality in the preparation of lignin bio-based materials.

Preparation and Characterization of Ethanol Extract of Spons Xestospongia sp.

Background: Xestospongia sp. is a species of the Demospongiae class that can be used as a medicinal substance. Xestospongia sp is known to have various activities such as anticancer, antibiotic, anti-fungal, cardiotonic, and antimalarial. One of the ways to make the formulation of natural ingredients is the phytosome vesicle technique. This method can be used to increase the penetration of compounds through cell membranes, increase their absorption and increase its bioavailability in the body. Objective: The aim of this study was to obtain the optimum phytosome composition in the ethanol extract of Xestospongia sp. and phosphatidylcholine with approprite vesicle characteristics. Methods: The preparation was carried out by varying the extract and phosphatidylcholine with a thin layer hydration method at a ratio of 1:1, 1:2, 2:1, and 2:2 and and phytosome characterization was carried out in each of these formulas to obtain the optimal formula. Results: In this study, the optimum phytosome formula has met the criteria based on morphological test parameters using an optical microscope obtained by spherical morphology, stability of physical appearance observations stored at 2oC-8oC ± 1oC temperature, pH measurement using a pH meter obtained a pH value of 4.20, and particle size determination using the Particle Size Analyzer (PSA) obtained a particle size of 180.6 nm and particle distribution value (IP) of 0.133. Conclusion: Composition of the optimum phytosome formula in the ratio of extract and phosphatidylcholine 1: 1 with the LUV phytosome category (Large Unilamellar Vesicle)

Analytical methods for detection and size determination of micro- and nanoscale plastic debris in water

<p>Development of analytical methods for the characterization (particle size determination, chemical identification, and quantification) of the low µm-range microplastic (MPs; 1-10 µm) and nanoscale plastic (NPs; 1-1000 nm) debris in environmental matrices is a quickly emerging scientific field and has gained considerable attention, not only within the scientific community, but also on the part of policy makers and the general public. However, due to the limited sensitivity of the current state of the art monitoring techniques, detection of MPs and NPs in water is one of the biggest challenges for their monitoring, source identification and, ultimately, risk assessment.</p><p>As it is evident that no single method will provide all the information required for a complete characterization of MPs and NPs in water, the present work is aimed to give an overview of different complementary analytical methodologies showing considerable promise for the particle size determination, chemical identification, and quantification of MPs and NPs [1]. In addition, results of three case studies will be included to adequately address the smallest fractions in plastic debris size determination, making such approaches worthwhile to be further explored.</p><p>The first case study offers a novel method based on the use of inductively coupled plasma-mass spectrometry operated in single-event mode and relies on our previous work where for the first time ever single particle inductively coupled plasma-mass spectrometry based on carbon monitoring was successfully used for the detection, particle size characterization and particle number concentration of polystyrene MPs [2]. The second case study further explore light scattering methods, including nanoparticle tracking analysis or dynamic light scattering, for MPs and NPs particle size distribution and particle number in water. Finally, the capabilities of size exclusion chromatography in combination with online detection techniques such as UV-visible absorption spectrometry will be presented for the particle size determination of smallest fraction of NPs (1-100 nm).</p><p> </p><p>M.V. is a senior postdoctoral fellow of the Research Foundation – Flanders (FWO 12ZD120N).</p><p> </p><p>References</p><p>[1] Velimirovic M., Tirez K., Voorspoels S., Vanhaecke F. (2020) Recent developments in mass spectrometry for the characterization of micro- and nanoscale plastic debris in the environment, Analytical and Bioanalytical Chemistry, 1-9.</p><p>[2] Bolea-Fernandez E., Rua-Ibarz A., Velimirovic M., Tirez K., and Vanhaecke F. (2020) Detection of microplastics using inductively coupled plasma-mass spectrometry (ICP-MS) operated in single-event mode. Journal of Analytical Atomic Spectrometry 35, 455-460.</p>

Mass spectrometry as a powerful analytical tool for the characterization of indoor airborne microplastics and nanoplastics

Development of analytical methods for the characterization (particle size determination, chemical identification, and quantification) of the low µm-range microplastics (MPs; 1-10 µm) and nanoplastics (NPs; 1 nm-1 µm) in air...

“DIY” Silica Nanoparticles: Exploring the Scope of a Simplified Synthetic Procedure and Absorbance-Based Diameter Measurements

In this study, the classical Stöber silica synthesis protocol was used to test the limits of simplification in the preparation and size determination of nanoparticles. The scope of three-ingredient, one-pot synthesis was established in conditions of regular 96% and 99.8% ethanol as solvent, with aqueous ammonia as the only source of base and water. Particles with diameters in the 15–400 nm range can be reliably obtained with this straightforward approach, and the direct relationship between the size and the product of concentrations of water and ammonia is evidenced. Furthermore, the idea of a linear approximation for Mie scattering in particular conditions is discussed, using experimental data and theoretical calculations. A simple, fast method for particle size determination utilizing a UV-Vis spectrophotometer—an easily accessible instrument—is explained, and shows a level of error (<0.5 SD) that can be acceptable for less rigorous laboratory use of nanoparticles or serve as a quick means for testing the influence of minor alterations to known synthetic protocols. This work aims to show that nanoparticle synthesis can (and should) become a regular occurrence, even in non-specialized labs, facilitating research into their new applications and inspiring outside-the-box solutions, while discussing the drawbacks of a more relaxed synthetic regimen.