SciCombinator

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Concept: Plasticizer

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The occurrence of microplastics (MPs) in saltwater bodies is relatively well studied, but nothing is known about their presence in most of the commercial salts that are widely consumed by humans across the globe. Here, we extracted MP-like particles larger than 149 μm from 17 salt brands originating from 8 different countries followed by the identification of their polymer composition using micro-Raman spectroscopy. Microplastics were absent in one brand while others contained between 1 to 10 MPs/Kg of salt. Out of the 72 extracted particles, 41.6% were plastic polymers, 23.6% were pigments, 5.50% were amorphous carbon, and 29.1% remained unidentified. The particle size (mean ± SD) was 515 ± 171 μm. The most common plastic polymers were polypropylene (40.0%) and polyethylene (33.3%). Fragments were the primary form of MPs (63.8%) followed by filaments (25.6%) and films (10.6%). According to our results, the low level of anthropogenic particles intake from the salts (maximum 37 particles per individual per annum) warrants negligible health impacts. However, to better understand the health risks associated with salt consumption, further development in extraction protocols are needed to isolate anthropogenic particles smaller than 149 μm.

Concepts: Water, Polymer, Carbon, Plastic, Polypropylene, Polyethylene, Plasticizer, Polyethylene terephthalate

29

Di-(2-ethylhexyl) phthalate (DEHP) is a plasticizer widely used in the production of poly-(vinyl) chloride (PVC) materials. It is a reproductive and developmental toxicant in animals and a suspected endocrine modulator in humans. DEHP is not covalently bound within the PVC molecule, which is why migration into a suitable medium can be expected. Since application of infusion solutions is one of the most common medical treatments, the objective of this study was to determine the migration of phthalates from softened PVC storage bags into infusion solution in different time periods within one year from date of production using a gas chromatography-mass spectrometry method. The measured values of DEHP ranged between 0.22 and 14.00 µg l(-1) , but the unexpected presence of other phthalate esters was also detected. It was concluded that values obtained in infusion solutions match the reference data and represent a minor risk for the patient. The presence of other phthalate esters leads to the conclusion that the pharmacopeic requirement for polymer cleanness was not fully met. Since phthalate esters are among the most extensively used industrial chemicals and are widely distributed in the environment, special precautions and further monitoring should be conducted to minimize any possible health risks.

Concepts: Chemistry, Plastic, Phthalates, Phthalate, Plasticizer, Bis(2-ethylhexyl) phthalate, Plasticizers, Diisononyl phthalate

28

Human exposure to phthalates was assessed through digestive and respiratory intakes. Six phthalates (DMP, DEP, DnBP, BBP, DEHP, DnOP) were investigated in drinking water, in current foodstuff and in ambient air. Digestive intake was prevailing (92 %) with a major contribution of food (95.5 %). Phthalate intake from water was mainly due to bottled water (60 %) in spite of the minor volume absorbed daily. From the respiratory tract, it was dominated by DEP: 30.3 ng kg(-1) bw day(-1) and the part played by indoor air prevailed. Total intake were as ng kg(-1) bw day(-1), for DEHP: 1458, DnBP: 191.8, BBP: 164.3, DEP: 107.7, DMP: 79.1.

Concepts: Water, Assessment, Phthalates, Phthalate, Bottled water, Plasticizer, Intake, Bis(2-ethylhexyl) phthalate

28

An electrostatic dry coating process based on a liquid pan coater was developed for enteric coating of tablets with Eudragit(®) L100-55. Two different liquid plasticizers of triethyl citrate (TEC) and PEG400 were used in the coating process. In contrast to TEC, PEG400 produced good powder adhesion and successful coating. DSC results showed that PEG 400 lowered the glass transition temperature (T(g)) of Eudragit(®) L100-55 to a greater extent than TEC at the same blend ratio, indicating that PEG400 was more effective in plasticizing the polymer. PEG 400 showed higher contact angle on both surfaces of tablet cores and coating powders as well as lower absorption into the tablet cores than TEC, suggesting that more PEG400 existed at the interface between tablet core and coating powders. The combination effects of higher plasticizing efficiency and more PEG400 available at the tablet surface produced higher plasticization of Eudragit(®) L100-55, leading to the successfully initial powder adhesion. The powder adhesion was further enhanced by the electrostatically assisted coating process, as confirmed by the higher coating level and coating efficiency with electrical charging (60 kV) than the ones without it (0 kV). The micrographs of scanning electron microscopy and in vitro drug release tests of the coated tablets showed that higher curing temperature and longer curing time led to enhanced film formation and acid resistance. The electrostatic dry coating process has been demonstrated to be a promising process for enteric coating of tablets.

Concepts: Electron, Pharmacology, Liquid, Differential scanning calorimetry, Scanning electron microscope, Glass transition, Coatings, Plasticizer

28

The emission of di-2-ethylhexyl phthalate (DEHP) from vinyl flooring (VF) was measured in specially designed stainless steel chambers. In duplicate chamber studies, the gas-phase concentration in the chamber increased slowly and reached a steady state level of 0.8-0.9 μg/m(3) after about 20 days. By increasing the area of vinyl flooring and decreasing that of the stainless steel surface within the chamber, the time to reach steady state was significantly reduced, compared to a previous study (1 month versus 5 months). The adsorption isotherm of DEHP on the stainless steel chamber surfaces was explicitly measured using solvent extraction and thermal desorption. The strong partitioning of DEHP onto the stainless steel surface was found to follow a simple linear relationship. Thermal desorption resulted in higher recovery than solvent extraction. Investigation of sorption kinetics showed that it takes several weeks for the sorption of DEHP onto the stainless steel surface to reach equilibrium. The content of DEHP in VF was measured at about 15% (w/w) using pressurized liquid extraction. The independently measured or calculated parameters were used to validate an SVOC emission model, with excellent agreement between model prediction and the observed gas-phase DEHP chamber concentrations.

Concepts: Adsorption, Phthalate, Solution, Steel, Stainless steel, Plasticizer, Polyvinyl chloride, Bis(2-ethylhexyl) phthalate

28

A method based on gas chromatography-mass spectrometry (GC-MS) combined with a pressurised liquid extraction (PLE) to determine four organophosphates, seven phthalate esters and bis(2-ethylhexyl) adipate in particulated material of harbour air samples has been developed. Some studies show that these compounds may cause hormone disrupting effects on human health. Moreover, the U.S. Environmental Protection Agency (EPA) has classified benzyl butyl phthalate and di(2-ethylhexyl) phthalate as possible human carcinogens.The chromatographic time per run analysis is less than 15min and the complete separation of all compounds is achieved. The PLE was optimised with recoveries above 90% and the repeatability of the method with real samples is less than 11% (%RSD, n=4). The MDLs (0.004-0.4ngm(-3)) and MQLs (0.02-2ngm(-3)) are limited by the fact of some compounds are present in low levels in sampling blank filters.The method was successfully applied in several samples and most of the compounds under study were found. The most relevant values were the high concentration of di-iso-butyl phthalate (between 28 and 529ngm(-3)) and the significant concentration of di(2-ethylhexyl) phthalate (between MQL and 22ngm(-3)). In addition, benzyl butyl phthalate was also detected in some samples but at low concentration levels (between MQL to 0.2ngm(-3)).

Concepts: Mass spectrometry, Concentration, Chromatography, Analytical chemistry, United States Environmental Protection Agency, Phthalates, Phthalate, Plasticizer

28

Starch extruded in the presence of a plasticizer results in a material called thermoplastic starch (TPS). TPS mixed with poly(butylene adipate co-terephthalate) (PBAT), soybean oil (SO), and surfactant may result in films with improved mechanical properties due to greater hydrophobicity and compatibility among the polymers. This study characterized films produced from blends containing 65% TPS and 35% PBAT with SO added as compatibilizer. The Tween 80 was added to prevention of phase separation. The elongation and resistance were greater in the films with SO. The infrared spectra confirmed an increase in ester groups bonded to the PBAT and the presence of groups bonded to the starch ring, indicating TPS-SO and PBAT-SO interactions. The micrographs suggest that the films with SO were more homogenous. Thus, SO is considered to be a good compatibilizer for blends of TPS and PBAT.

Concepts: Ester, Soybean, Hydrolysis, Plasticizer, Paint

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Some phthalates are endocrine disruptors and reproductive and developmental toxicants. Data on newborn phthalate exposure and elimination characteristics are scarce. We determined 21 urinary phthalate metabolites (indicating exposure to 11 parent phthalates) in two study approaches: in the first approach we collected the urine of 20 healthy newborns at days 2-5 post partum together with 47 urine samples of 7 women during pregnancy. In the second fine tuned approach we collected first urine samples of 9 healthy newborns together with their mother’s urine shortly before birth. To ensure full and contamination free collection of the newborns first urines we used special adhesive urine bags for children. All urine samples revealed ubiquitous exposures to phthalates comparable to other populations. Metabolite levels in the newborns first day urine samples were generally lower than in all other samples. However, the newborns urines (both first and day 2-5 urines) showed a metabolite pattern distinctly different from the maternal and general population samples: in the newborns urines the carboxy-metabolites of the long chain phthalates (DEHP, DiNP, DiDP) were the by far dominant metabolites with a relative share in the metabolite spectrum up to 6 times higher than in maternal urine. Oppositely, for the short chain phthalates (DBP, DiBP) oxidized metabolites seemed to be less favored than the simple monoesters in the newborns urines. The skewed metabolite distribution in the newborns urine warrants further investigation in terms of early phthalate metabolism, the quantity of internal phthalate exposure of the fetus/newborn and its possible health effects.

Concepts: Pregnancy, Childbirth, Infant, Metabolism, Phthalates, Phthalate, Plasticizer, Bis(2-ethylhexyl) phthalate

26

The daily intakes (DI) were estimated in a Belgian general population for 5 phthalates, namely diethyl phthalate (DEP), di-n-butyl phthalate (DnBP), di-iso-butyl phthalate (DiBP), butylbenzyl phthalate (BBzP) and di-2-ethylhexyl phthalate (DEHP), based on the urinary measurements of their corresponding metabolites. DI values ranged between

Concepts: Risk, Phthalates, Phthalate, Diethyl phthalate, Plasticizer, Intake, Bis(2-ethylhexyl) phthalate, Plasticizers

24

Two novel cefquinome sulfate (CFQ)-selective electrodes were performed with dibutyl sebacate as a plasticizer using a polymeric matrix of polyvinyl chloride. Sensor 1 was prepared using sodium tetraphenylborate as a cation exchanger without incorporation of ionophore, whereas 2-hydroxy propyl β-cyclodextrin was used as ionophore in sensor 2. A stable, reliable, and linear response was obtained in concentration ranges 3.2 × 10(-5) to 1 × 10(-2) mol/L and 1 × 10(-5) to 1 × 10(-2) mol/L for sensors 1 and 2, respectively. Both sensors could be sufficiently applied for quantitative determination of CFQ in the presence of degradation products either in bulk powder or in pharmaceutical formulations. Sensor 2 provided better selectivity and sensitivity, wider linearity range, and higher performance. Therefore it was used successfully for accurate determination of CFQ in biological fluids such as spiked plasma and milk samples. Furthermore, an online kinetic study was applied to the CFQ alkaline degradation process to estimate the reaction rate and half-life with feasible real-time monitoring. The developed sensors were found to be fast, accurate, sensitive, and precise compared with the manufacturer’s reversed-phase chromatographic method.

Concepts: Cathode, Electrochemistry, Chemistry, Sodium chloride, Stability, Plasticizer, Polyvinyl chloride, Electrodes