Water Insoluble Research Articles

Novel Composition Comprising Poorly Water Soluble or Water Insoluble Actives and Their Solubility and Dissolution Enhancement

Parkinson’s disease is a chronic and progressive movement disorder that affects millions of people worldwide. There are several new therapies that have been developed to help manage the symptoms of Parkinson’s disease. Treatment options for PD are limited, with most of the current approaches based on restoration of dopaminergic tone in the striatum. However, these do not alter disease course and do not treat the non-dopamine-dependent features of PD such as freezing of gait, cognitive impairment, and other non-motor features of the disorder, which often have the greatest impact on quality of life. Despite the obstacles created by the COVID-19 pandemic on the research community, in 2021 to 2022, there were 147 active clinical trials–62% of which were studying symptomatic treatments with the remaining investigating potential disease-modifying therapies. Since the 1960s, levodopa has remained the mainstay of PD treatment, with recent advances in novel delivery mechanisms including inhaled and continuous infusions of levodopa. As understanding of PD pathogenesis grows, novel therapeutic avenues are emerging. In this review, advance therapy to treat Parkinson disease is discussed. This review also provides current strategies for the treatment of Parkinson.

Efficiency of Magnetically Treated Water on Decontamination of Chlorpyrifos® Residual: A Practically Water Insoluble Organophosphate in Brassica chinensis Linn.

Chlorpyrifos® (Thaion Agro Chemical CO., Ltd. Yannawa, Bangkok 10120, Thailand) (an almost water insoluble organophosphate insecticide) has been extensively used, resulting in the presence as a surface contaminant in foodstuffs, surface streams and soils. It is thus critically essential to develop methods to degrade or remove and eliminate this pollutant from environments. Chlorpyrifos® has very limited solubility and so it is primarily a contaminant of the surfaces of foodstuffs. We present the effect of magnetically treated water (MTW) to remove Chlorpyrifos® contaminating in Brassica chinensis Linn., a commonly eaten vegetable in Thailand and globally. Samples were washed with magnetically treated water (MTW) prior to detection of Chlorpyrifos® with GC-MS (Gas Chromatograph-Mass Spectroscopy). Chlorpyrifos® was removed by a factor of 413 times (−99.7%) by MTW compared to the un-washed sample, whereas the removal factor for tap water washing was only 9.6 (−89%). The MTW washed material easily passed safety criteria (Maximum Residue Load—MRL), but the tap water washed vegetables did not do so reliably. Although Chlorpyrifos® may be banned in many countries, the binding properties of replacement organophosphates are likely to be similar, and so our results should generalize to pesticides in the organophosphate chemical class that are not readily water soluble.

Co-Hydrotreatment of Yellow Greases and the Water-Insoluble Fraction of Pyrolysis Oil. Part I: Experimental Design to Increase Kerosene Yield and Reduce Coke Formation

This paper reports the co-hydrotreatment of Biomass Technology Group commercial pyrolysis oil water-insoluble (WIS) phase (also known as pyrolytic lignin) and yellow greases (waste cooking oil), aiming to produce sustainable aviation fuels (SAFs). We use a sulfided NiMo/Al2O3 blend with 16 wt % WIS and a central composite experimental design to identify processing conditions increasing kerosene yield and reducing coke formation. The input variables were: (1) reaction temperature (320, 350, and 380 °C), (2) initial hydrogen pressure (5, 6, and 7 MPa), and (3) amount of catalyst (0.7, 1.0, and 1.3 g). The hydrotreated oily phases were distilled to obtain gasoline (<150 °C), kerosene (150–250 °C), diesel (250–350 °C), and residual oil (>350 °C). The reaction temperature is the main factor affecting the yield of gaseous, solid, and liquid products. Meanwhile, a higher initial hydrogen pressure and catalyst loading increased the yield of kerosene and other distillates and decreased the coke formation. A high temperature correlated with a lower content of oxygenates in kerosene cuts. Based on our experimental results, we propose to conduct hydrotreatment studies at 380 °C, initial H2 pressure of 7 MPa, and 1.3 g of catalyst. Under the identified conditions, it was possible to improve the kerosene yield to more than 20 wt % and reduce the yield of coke to close to 2.0 wt %. The chemical composition and fuel properties of the gasoline, kerosene, and diesel cuts were thoroughly analyzed. The content of aromatics and phenols in the kerosene fraction produced at the conditions identified in this project exceeded the recommended values for SAFs. New strategies (such as blending and more intense hydrotreatment to remove oxygenated compounds) need to be implemented to reduce the content of these molecules in our final product.

Pollution characteristics of environmental persistent free radicals (EPFRs) and their contribution to oxidation potential in road dust in a large city in northwest China.

Environmental persistent free radicals (EPFRs) are new environmental health risk substances in the atmosphere, and their oxidative toxicity (OT) has not been strongly confirmed. In this study, the fugitive characteristics of EPFRs in road dust in a metropolitan city located in northwest China, and their potential oxidative toxicity were investigated. The results showed that the road dust contains Carbon-centered EPFRs with the mean mass concentration of (6.6±5.0) ×1017 spins/g. EPFRs in road dust are degradable and have a half-life of 4.5 years. The water insoluble (WIS) components contribute 71% to the oxidative toxicity of road dust and show a rapid toxicity generation process, while the oxidative toxicity generation rate of water-soluble dust is more stable. Based on the positive matrix factorization (PMF) model, the contribution of EPFRs-dominated factors to Total-OT and WIS-OT is 17.3% and 33.3%, respectively. The PMF model results indicated that different types of EPFRs contributed differently to the oxidative toxicity of road dust and Carbon-centered EPFRs are more likely to participate in reactive oxygen species generation. Our results highlight that the EPFRs are an important contributor to the oxidative toxicity of atmospheric particulate matter, and their oxidative toxicity is dependent on the types of free radicals. It also provides an important insight into the influence of other potentially toxic substances on the oxidative toxicity of atmospheric PM.

Wetting properties of fresh urban soot particles: Evaluation based on critical supersaturation and observation of surface trace materials

Soot particles strongly absorb solar radiation and contribute to global warming. Also, wetting properties of soot at emission can affect its lifetime. We investigated surface conditions related to wetting and hydrophobic properties of fresh soot using data from measurements taken in Tokyo. A cloud condensation nuclei (CCN) counter was used to clarify surface conditions of particles composed mainly of water-insoluble (WI) materials: total and active particles as CCN around critical supersaturation (Sc) of 203-nm-diameter WI particles. Averaged number fractions of inactivated particles as CCN at 1.05% supersaturation (SS), which is Sc of hydrophilic WI particles, were estimated as 1.4%. Number fractions of inactive particles changed less at 1.78%SS during rush hour and increased at 0.89%SS, implying that most of the WI particles included small amounts of water-soluble (WS) materials rather than being completely hydrophobic. Based on transmission electron microscope (TEM) analysis of samples collected during rush hour, 69% of the mostly bare soot particles had Na or K small domains that are regarded as originating in fossil fuels. Based on water dialysis analysis results, some Na and K on soot were WS. Combination results with CCN measurements suggest that these WS materials decrease the Sc of soot. Moreover, the morphological structure of sulfate covering Na and K domains on the soot surface implicates pre-existing sodium and potassium compounds on soot as a trigger of soot aging. However, inactive particles at Sc at poor-hydrophilic particles and soot particles composed solely of WI materials on TEM samples were also found, although they were minor. Such particles, which are unfavorable for obtaining a wettable surface, might retain non-hygroscopicity for a longer period in the atmosphere. Evaluation of long-range soot transport can benefit from consideration of slight and inhomogeneous differences of chemical compounds on soot that occur along with their emission.

The Acute Effect of Diesel Exhaust Particles and Different Fractions Exposure on Blood Coagulation Function in Mice.

The toxicity and widespread exposure opportunity of diesel exhaust particles (DEP) has aroused public health concerns. This study aimed to investigate the acute effect of DEP and different fractions exposure on blood coagulation function in mice. In this study, nine- week-old C57BL/6J male mice were divided into four exposure groups (with 15 mice in each group). The water-soluble (WS) and water-insoluble (WIS) fractions of DEP were isolated, and intratracheal instillation was used for DEP, WS and WIS exposure. The phosphate buffer saline (PBS) exposure group was set as the control group. After 24 h exposure, the mice were sacrificed for blood routine, coagulation function and bleeding time examinations to estimate the acute effect of DEP, WS and WIS exposure on the blood coagulation function. In our results, no statistically significant difference in weight of body, brain and lung was observed in different exposure groups. While several core indexes in blood coagulation like bleeding time (BT), fibrinogen (FIB), activated partial thromboplastin time (APTT) and prothrombin time (PT) altered or showed a lower tendency after DEP, WS and WIS exposure. For example, BT was lower In WIS exposure group (211.00 s) compared with PBS exposure group (238.50 s) (p < 0.01), and FIB was lower in WS exposure group (233.00 g/L) compared with PBS exposure group (249.50 g/L) (p < 0.05). Additionally, systemic inflammation-related indexes like white blood cell count (WBC), neutrophil count (NEUT), lymphocyte count (LYMPH) altered after DEP, WS and WIS exposure. In conclusion, DEP, WS and WIS fractions exposure could result in the hypercoagulable state of blood in mice. The noteworthy effects of WS and WIS fractions exposure on blood coagulation function deserve further investigation of the potential mechanism.

Taste Masking of Granulated Acetaminophen by Water Insoluble Ethylcellulose Coating.

Bitter tasting of drugs leads to non-compliance especially in the case of pediatric patients due to their inability to swal-low medication. In this study, we aimed to mask the bitter taste of acetaminophen (APAP) particles through coating. A pH independent water insoluble ethylcellulose polymer was used to coat the APAP. The coating of water insoluble ethylcellulose on APAP can have a significant impact on the dissolution profile. Various grades of APAP were used for coating; fine grade, Compap L90% having wide particle size distribution (PSD), and a special granular (SG) APAP 1680 having narrow PSD. Coating was performed using top spray (Vector) for Compap L90% and SG APAP 1680 grade of APAP. Bitter taste of SG APAP was masked after spraying dispersion equivalent to a weight gain of 10% compared to 35% used for Compap L90%. Using bottom spray (Wurster coater, GPCP 2.0), coating was performed on SG APAP 1680 grade of APAP by spraying aqueous dispersion of ethylcellulose (Surelease) equivalent to a weight gain of 10%. The scalability of the top spray process was also evaluated in GPCG 30 and bitter taste was masked by using Surelease dispersion equivalent to a weight gain of 6%. Coated APAP was examined for particle size (PS), particle size distribution (PSD), flowability, and drug release profile. Dissolution was performed using USP apparatus 2 and 4 in phosphate buffer and evaluated for mechanism of drug release. Particle size obtained for coated SG APAP 1680 via top and bottom spray process was 404 µm d(90) and 487 µm d(90) respectively. The results of the study demonstrated the potential of Surelease dispersion in taste masking. The use of SG APAP 1680 having narrow PSD allowed taste masking to achieve at low weight gain without greatly affecting the dissolution profile.

An Evaluation on the Electrochemical Recovery of Indium from Water Insoluble Indium Oxide in a Choline Chloride-Malonic Acid Eutectic Electrolyte

The use of deep eutectic solvents for the dissolution and electrochemical recovery of indium from water insoluble In2O3 was evaluated. While In2O3 did not dissolve appreciably in choline chloride/ethylene glycol (molar ratio 1:2) and choline chloride/urea (molar ratio 1:2), it dissolved well in choline chloride/malonic acid (molar ratio 1:2) up to 0.1 M at 373 K. Cyclic voltammograms recorded on several types of electrode including GC, Cu, and Mo indicated that the reduction of In(III) to In on Cu and Mo substrates was complicated by hydrogen evolution reaction (HER) but not so seriously on GC due to the higher overpotential required for HER on GC electrode. Because of the HER, the current efficiency of the electrodeposition of In on Cu Mo electrodes was lower than on carbon electrode. Chronoamperometry results indicated that the deposition of In was possibly involved with the three-dimensional (3D) progressive nucleation on the Cu electrode, and 3D instantaneous nucleation on the GC electrode, respectively. Images taken by scanning electron microscopy (SEM) revealed the surface morphology of In electrodeposits was dependent on the electrode materials and applied potential. Crystalline In deposits on these substrates was confirmed by X-ray powder diffraction (XRD) patterns.

Traditional Manufacturing Procedure of Guduchi Satwa; Sedimental Water Insoluble Starchy Extract of Tinospora cordifolia willd. Miers &amp; its Process Validation

Traditional Manufacturing Procedure of Guduchi Satwa; Sedimental Water Insoluble Starchy Extract of Tinospora cordifolia willd. Miers &amp; its Process Validation

Temperature data during steam pressure filtration in combination with a water insoluble pore liquid.

Data presented in this article focus on the application of steam pressure filtration in combination with a water insoluble pore liquid. The article describes measured temperature profiles during steam pressure filtration within a filter cake. This article is co-submitted to the article ‘Steam Pressure Filtration in Combination with a Water Insoluble Pore Liquid’ [1] (DOI: 10.1016/j.ces.2020.115782) where the occurring phenomena as well as the interpretation of temperature profiles during steam pressure filtration are explained in detail. The article expands the shown data to other material systems.

Asp isomerization increases aggregation of α-crystallin and decreases its chaperone activity in human lens of various ages

α-Crystallin, comprising 40-50 subunits of αA- and αB-subunits, is a long-lived major soluble chaperone protein in lens. During aging, α-crystallin forms aggregates of high molecular weight (HMW) protein and eventually becomes water-insoluble (WI). Isomerization of Asp in α-crystallin has been proposed as a trigger of protein aggregation, ultimately leading to cataract formation. Here, we have investigated the relationship between protein aggregation and Asp isomerization of αA-crystallin by a series of analyses of the soluble α-crystallin, HMW and WI fractions from human lens samples of different ages (10-76years). Analytical ultracentrifugation showed that the HMW fraction had a peak sedimentation coefficient of 40S and a wide distribution of values (10-450S) for lens of all ages, whereas the α-crystallin had a much smaller peak sedimentation coefficient (10-20S) and was less heterogeneous, regardless of lens age. Measurement of the ratio of isomers (Lα-, Lβ-, Dα-, Dβ-) at Asp58, Asp91/92 and Asp151 in αA-crystallin by liquid chromatography-mass spectrometry showed that the proportion of isomers at all three sites increased in order of aggregation level (α-crystallin < HMW<WI fractions). Among the abnormal isomers of Asp58 and Asp151, Dβ-isomers were predominant with a very few exceptions. Notably, the chaperone activity of HMW protein was minimal for lens of all ages, whereas that of α-crystallin decreased with increasing lens age. Thus, abnormal aggregation caused by Asp isomerization might contribute to the loss of chaperone activity of α-crystallin in aged human lens.

ACUTE TOXICITY OF WATER SOLUBLE, INSOLUBLE AND WHOLE CRUDE FRACTIONS (BONNY LIGHT) ON THE EARLY LIFE STAGES OF HOPLOBATRACHUS OCCIPITALIS (CROWNED BULL FROG) IN CALABAR, NIGERIA

This study examined the effect of different concentrations of bonny light crude oil on the development and growth of the tadpoles of the crowned bullfrogs. After series of range finding tests (RFT) the tadpoles of H. occipitalis were exposed to acute and sub-lethal log concentrations of 0.00 ppm, 1.00 ppm, 1.30 ppm, 1.48 ppm, 1.60 ppm, 1.65 ppm and1.69 ppm of different fractions of bonny light crude for 96 hours. The various fractions of crude recorded no significant differences in mortalities (P &gt; 0.05) for three- and four-weeks old tadpoles. The mortalities increased with increase in concentration of toxicants. The tadpoles recorded 75% mortalities in Water Soluble Fraction (WSF), 65 % mortalities in Water Insoluble Fraction (WIF) and 70 % and 75 % mortalities respectively in Whole Crude (WC). The WSF of crude showed the lowest LC50’s in the tadpoles ranging from 1.51 ± 0.17 ppm with (lower limit 1.45 and upper limit 1.55) to 1.61 ± 0.37 ppm with (lower limit 1.58 and upper limit 1.65). WIF showed the highest LC50’s in the tadpoles ranging from 1.62 ± 0.42 with (lower limit 1.59 and upper limit 1.66) to 1.69 ± 0.41ppm with (lower limit 1.55 and upper limit 1.62). The WC showed an LC50’s range of 1.60 ± 0.37 ppm with (lower limit 1.56 and upper limit 1.64) to 1.63 ± 0.32 ppm with (lower limit 1.59 and upper limit 1.66). Results shows that increased toxicity produced higher mortalities in tadpoles of H. occipitalis (an endangered species). This study therefore advocates that Oil companies should adhere to the current WHO / FEPA regulatory limits of 0.2 mg/l to 14.0 mg/l for C5 – C22 hydrocarbons to ensure the survival of its vital ecological niche. &#x0D; Mowang, A. D. | Department of Zoology and Environmental Biology, University of Calabar, Nigeria.

Rapid Nondestructive Fractionation of Biomass (≤15 min) by using Flow-Through Recyclable Formic Acid toward Whole Valorization of Carbohydrate and Lignin.

Whole valorization of carbohydrate and lignin from biomass was achieved by rapid flow-through fractionation (RFF) within 15 min. Wheat straw was effectively deconstructed into its principle components without degradation by using easily recyclable aqueous formic acid (72 wt %) at 130 °C. The obtained cellulose-rich solid showed a nearly complete glucan recovery and 73.8 % glucose conversion after enzymatic hydrolysis. Xylan also reached full recovery with negligible furfural formation with a sum of 80 % of oligo/mono xylose in spent liquor and 20 % of xylan remaining in the solid. Up to 75.4 % lignin was dissolved in the spent liquor and further fractionated into water-insoluble (WIL) and water-soluble lignin (WSL) by dilution with water. WIL showed a non-condensed and well-preserved structure with 84.5 % β-O-4 remaining, which is believed to be beneficial for catalytic conversion into low-molecular-weight chemicals and fuels. The concentration of employed formic acid was below the formic acid/water azeotrope, and therefore the reaction medium could be restored through simple distillation. Together with the joint valorization of lignin and carbohydrates, the presented RFF is a promising process for sustainable biorefinery.

Synthesis and Evaluation of Water Insoluble but Swellable Bioadhesive Polymer for Ocular Drug Delivery

Abstract: Introduction: Our main purpose of present study was to find out the effect of different crosslinking agents along with its concentration during polymer synthesis and to find the most suitable polymer for ocular drug delivery with optimum bioadhesive strength and less irritation potential. It was expected that the synthesized polymer will remain adhered to the conjunctival mucin layer thus preventing loss of drug by precorneal factors. Materials and Methods: Acrylic acid procured from Loba chemicals was polymerized with Divinyl glycol from Merck specialities Private limited, Divinylbenzene and 2, 5-dimethyl-1, 5-hexadiene from Alfa Aesar to form water insoluble swellable polymer. Different parameters like density, polymer hydration, Differential Scanning Calorimetry, Infra-Red spectroscopy, X ray diffraction and mucoadhesive strength were determined. Polymer hydration was studied with respect to time, pH and ionic strength. HET-CAM test and Draize skin irritation test was performed to evaluate the degree of irritation caused by these polymers. Results and Discussion: It was found that as more hydrophobic groups were introduced in the polymer structure, hydration potential was reduced. The effect of concentration of crosslinking agent on bioadhesive strength was significant. With increase in density of crosslinking agent, the bioadhesive strength decreased. Polymers were found to be non-irritant to slight irritant in nature. Key words: Bioadhesion, Ocular, Water Insoluble polymer, Acrylic acid, Hydration.

Sequential fractionation of lignin-derived pyrolysis oil via extraction with a combination of water and organic solvents

Alkali lignin pyrolysis oil (PO) was subjected to a sequential extraction method in which PO was separated into water soluble (WS), water insoluble (WI), methanol soluble (MS), methanol insoluble (MI), dichloromethane soluble (DS), and dichloromethane insoluble (DI) subfractions via combinations of water and organic solvents (water, methanol, and dichloromethane). Several analytical techniques were used to characterize PO and its subfractions. Elemental analysis showed that the higher heating value (HHV) of DS was highest, and there was higher aromaticity in the MI fraction, while the DI fraction had lower aromaticity. Interestingly, gas chromatography–mass spectrometry (GC–MS) and positive ion electrospray high resolution mass spectrometry (ESI+–HRMS) analyses showed that both the MI and DI subfractions were lignin-derived oligomers, which accounted for 25.0% of the total mass of the original PO. Additionally, the oligomers in the PO were mainly composed of dimers to pentamers. The secondary tandem MS/MS (MS2) experiments revealed that the m/z 360 is a dimer linked by coniferyl alcohol and a ferulate linkage, and no further fragmentation was observed in both the m/z 475 and 701 due to the rigidity of these structural motifs.

Fractionation of pyrolysis oil derived from lignin through a simple water extraction method

Abstract Great effort has been exerted to develop better, more effective fractionation techniques and improve the quality of bio-oil. Water extraction can be regarded as an effective method for bio-oil fractionation. In this study, fractionation of pyrolysis oil into water-soluble (WS) and water-insoluble (WI) phases by water extraction was investigated, and the influence of several factors, including water-to-oil ratio and water temperature, on the performance of the method were evaluated via several analytical techniques. When the water-to-oil ratio was 20:1 and the extraction temperature was 20 °C, polar and non-polar components were enriched in the WS (36.56 wt%) and WI (63.44 wt%) phases, respectively. Although extraction temperature had no significant effect on the properties of WS and WI, the distribution of polar and non-polar components was markedly affected by the dispersion and polarity of the compounds. 2D HSQC-NMR results revealed that side chain structures were more sensitive than aromatic structures to temperature. In view of these findings, an effective energy- and resource-saving extraction method featuring a water-to-oil ratio of 20:1 and extraction temperature of 20 °C is recommended for optimal water fractionation of pyrolysis oil.

Fast pyrolysis of tannins from pine bark as a renewable source of catechols

Fast pyrolysis of water-insoluble (W-I) tannins—mainly composed of condensed tannins—obtained from Pinus radiata bark methanol-water extraction was carried out in pursuit of a renewable source of high-value chemicals, in particular catechols. Micropyrolysis in an isothermal furnace unit (Py-GC–MS/FID) was performed between 450–600 °C. Catechin and W-I tannins were compared to establish thermal degradation behavior between this fraction and its representative monomer constituent. Additionally, W-I tannins were compared with typical sources of renewable phenols such as pine bark and organosolv-lignin in order to highlight its potential. Bench-scale experiments of W-I tannins were performed in a fluidized bed reactor between 400–600 °C to provide information related to yield and concentration of catechols. The Py-GC–MS/FID results showed that W-I tannins are prolific of catechol and 4-methylcatechol, similar to their most abundant monomer constituent catechin. However, W-I tannins are not only composed of condensed tannins and some substituted polycyclic aromatic hydrocarbons, triterpenes and carbohydrate-derived compounds were detected. The comparison of pyrolysis products among the renewable sources of phenols showed that W-I tannins yielded the highest relative content of catechols while guaiacols and carbohydrate-derived compounds predominated in the composition of lignin and bark products, respectively. The optimal pyrolysis-oil yield for bench scale assays (37 wt%) was found at 550 °C and maximum yield of both catechol (4.4 wt%) and 4-methylcatechol (2.3 wt%) were also obtained at 550 °C.

Biophysical characterization of asolectin-squalene liposomes.

Liposomes are shell nanoparticles able to embed hydrophobic molecules into their lipid layers to be released to cells. In pharmaceutical sciences, liposomes remain the delivery system with the highest biocompatibility, stability, loading characteristics, tunable physicochemical properties. Squalene is a natural, water insoluble, lipid, abundant in olive oil and shark liver. Studies in vitro and in animal models suggest protective and inhibitory effects of squalene against cancer. To study its effect on cells, and to overcome its insolubility in water, we have designed and produced large unilamellar liposomes containing different quantities of this terpene (0%, 2.8%, 5% w/w). Liposomes have been characterized by different biophysical techniques. Size-exclusion and affinity chromatography showed a unimodal size distribution and confirmed the squalene loaded dose. Laurdan fluorescence evidenced the changes in the hydration of the external layer of liposomes as a function of squalene concentration. Dynamic light scattering and small angle X-ray scattering revealed squalene induced structural differences in the hydrodynamic radius distribution and in the bilayer thickness respectively. Finally, preliminary experiments on the effects of liposome-delivered squalene on tumor and non-tumor cell lines showed time- and dose-dependent cytotoxic effects on LAN5 tumor cells and no effect on NIH-3T3 normal cells.

Mass-size distribution and concentration of metals from personal exposure to arc welding fume in pipeline construction: a case report.

We investigate exposure to welding fume metals in pipeline construction, which are responsible for severe respiratory problems. We analyzed air samples obtained using size-fractioning cascade impactors that were attached to the welders performing shielded metal and gas tungsten arc welding outdoors. Iron, aluminum, zinc, chromium, manganese, copper, nickel, and lead concentrations in the water-soluble (WS) and water-insoluble (WI) portions were determined separately, using inductively coupled plasma mass spectrometry. The mass-size distribution of welding fume matches a log-normal distribution with two modes. The metal concentrations in the welding fume were ranked as follows: Fe>Al>Zn>Cr>Mn>Ni>Cu>Pb. In the WS portion, the capacities of metals dissolving in water are correlated with the metal species but particle sizes. Particularly, Zn, Mn, and Pb exhibit relatively higher capacities than Cu, Cr, Al, Fe, and Ni. Exposure of the gas-exchange region of the lungs to WS metals were in the range of 4.9% to 34.6% of the corresponding metals in air by considering the particle-size selection in lungs, metal composition by particle size, and the capacities of each metal dissolving in water.

Fe-Assisted Hydrothermal Liquefaction of Lignocellulosic Biomass for Producing High-Grade Bio-Oil

Although bio-oils produced by pyrolysis and hydrothermal synthesis demonstrate potential toward building a sustainable society, large amounts of char generated as a byproduct and their thermal instability owing to high oxygen content hinder their applications. Hence, a novel approach for the production of high-grade bio-oil was proposed herein. In this approach, zerovalent Fe was used as an agent for generating hydrogen in situ in the hydrothermal liquefaction of oil palm empty fruit bunch (EFB), a lignocellulosic biomass source, affording bio-oil containing water-soluble (WS) and water-insoluble (WI) fractions in high yields. Hydrogen generated by the reaction between Fe and H2O efficiently converted unstable intermediates obtained from the degradation of EFB into stable compounds, resulting in reduced char formation. Hydroxyketones were detected as components characteristic of the WS fraction in the H2O/EFB/Fe system, which were stable under hydrothermal condition. WS fractions were treated with the HZS...