Effect Of Salt Addition Research Articles

A novel cloud point extraction based on fatty acid deep eutectic solvent combined with high-performance liquid chromatography for determination of ultraviolet absorbent in food packaging bags

A fatty acid deep eutectic solvent (DES) based cloud point extraction (DES-CPE) coupled with high-performance liquid chromatography (HPLC) to determine ultraviolet absorbent (UV) in food packaging bags was presented. In this DES-CPE method, DESs prepared from medium-chain saturated fatty acids (C8-C12) and menthol are pH-dependent phase, and acid-base reactions can be carried out solely by adjusting the pH of the solution. The reaction conditions and extraction conditions, such as pH value, speed and time of vortex, selection and dosage of the extraction solvent, reaction time and temperature, effects of salt addition and centrifugation time were investigated in detail. Under optimal condition, the proposed method showed good linear range from 1 to 100μgmL−1, with good assuming regression coefficients (R2) ≥ 0.997. The limit of detection (LODs), the quantitation (LOQs), the repeatability (RSDs%) were in the range of 0.05–0.17 μgmL−1, 0.18–0.52 μgmL−1, 0.93–2.65%, respectively. The enrichment factor was 10 and the recoveries of three Ultraviolet absorbents were between 82.2% and 103.4%.

Simultaneous determination of drug active compound, hormones, pesticides, and endocrine disruptor compounds in wastewater samples by GC-MS with direct calibration and matrix matching strategies after preconcentration with dispersive liquid-liquid microextraction.

DLLME was coupled with GC-MS for the simultaneous determination of a drug active compound, hormones, pesticides, and endocrine disruptor compounds with high accuracy and reproducibility in this study. Extraction parameters that affect extraction output including types and volumes of dispersive and extraction solvents, and effect of salt addition were optimized to lower the detection limits for 12 compounds. Under the optimum conditions, LOD and LOQ values were found between 1.99-5.05 and 6.63-16.87 ng/mL, respectively. Spiked recovery tests were also applied to wastewater samples to check the applicability of the method. Matrix matching strategy was used to improve the overall recovery results of the analytes obtained for municipal wastewater. Two different municipal wastewater samples were used in the matrix matching studies. Percent recovery values calculated with the matrix matching experiments were between 85-114%. The results obtained indicated that the developed method could be applied for the determination of the analytes of interest with high accuracy and sensitivity.

Effect of Salt Addition upon the Production of Metabolic Compounds by Yarrowia lipolytica Cultivated on Biodiesel-Derived Glycerol Diluted with Olive-Mill Wastewaters

One of the major environmental problems is the highly toxic agro-industrial waste called olive mill wastewater (OMW), deriving from olive oil production. On the other hand, the continuous development of the biological liquid fuel industry (biodiesel and bioethanol) makes it mandatory the process and exploitation of their main by-products, crude glycerol. This study dealt with the biotechnological conversions of biodiesel-derived crude glycerol with the use of the non-conventional yeast Yarrowia lipolytica in media that had been diluted with OMWs. OMWs, employed as simultaneous liquid medium and substrate, is a new trend recently appearing in Industrial Biotechnology, where value-added metabolites could be produced with simultaneous partial detoxification (i.e. decolorization and phenol removal) of the used residue. In the present study, diluted OMWs (containing 2.0 g/L of total phenolic compounds) blended with 70.0 g/L crude glycerol were employed as substrates. Production of value-added compounds by Y. lipolytica strain ACA-YC 5031 was studied in nitrogen-limited media favoring the production of secondary metabolites (i.e. citric acid, polyols, microbial lipids, polysaccharides). Batch-flask cultures were carried out and the impact of the addition of different NaCl concentrations (1.0%, 3.0%, 5.0% w/w) added upon the biochemical behavior of the strain was studied. Remarkable biomass production was observed in all trials, while in the “blank” experiment (no OMWs and no salt added), the metabolism was shifted toward the synthesis of polyols (Σpolyols = mannitol + arabitol + erythritol > 20 g/L and maximum total citric acid-Cit (sum of citric and isocitric acid) = 10.5 g/L). Addition of OMWs resulted in Citmax = 32.7 g/L, while Σpolyols concentration dropped to <15 g/L. Addition of salt in the OMW-based media slightly reduced the produced biomass, while Cit production drastically increased, reaching a final value of 54.0 g/L (conversion yield of Cit produced per unit of glycerol consumed = 0.82 g/g) in the trial with addition of 5.0% NaCl. Finally, significant color and phenols removal were observed, evaluating the yeast as a decontamination medium for the OMW and a great candidate for the production of value-added compounds.

Effects of Salt on Anaerobic Digestion of Food Waste with Different Component Characteristics and Fermentation Concentrations

Effects of salt on anaerobic digestion are dosage-dependent. As salt is a widely used condiment in food processing, effects of salt are bound to be considered when food waste is digested. In this study, salt addition effects (0, 2, 4, 6, 9, 12 g∙L−1) on biogas and methane yields and kinetics of biogas production were researched. Meanwhile, component characteristics (food waste featured in carbohydrate, protein and fat, respectively) and fermentation concentrations (5 and 8 gVS∙L−1) were also taken into consideration. Results showed that 2–4 g∙L−1 salt addition was the optimal addition dosage for AD systems as they not only have the maximum biogas and methane yields, but also the maximum vs. removal in most cases. Also, according to the results of a modified Gompertz model, which is used to predict biogas and methane production rates, suitable salt addition can accelerate biogas production, improving the maximum biogas production rate (Rmax). Factorial design (2 × 2) proved that interaction of salt and fermentation concentrations was significant for food waste featured with carbohydrate and with protein (p < 0.05). High salt addition and fermentation concentration can break the AD system when the feeding material was food waste featured with carbohydrate, but for food waste featured with protein, interaction of fermentation concentrations and salt addition can alleviate inhibition degrees.

The Effect of Salt on the Structure of Individual Fat Globules and the Microstructure of Dry Salted Cheddar Cheese

Salting is an essential step in the production of Cheddar and other cheese varieties and is a well-studied process but the effect of salt addition on the microstructure of the milk ingredients and resulting cheese is not well known. This study provides insights into how the primary components in milk and the cheese matrix respond to salting. High concentrations of salt (15–25% (w/w) NaCl) disrupted fat globules due to the increased osmotic pressure. This led to fat coalescence, resulting in large fat globules >10 μm in diameter, together with submicron sized fat globules ~ 120–500 nm in diameter. Salt addition also prevented the visualization of the milk fat globule membrane when added at high concentrations (25% (w/w) NaCl) and induced asymmetry in liquid ordered domains at lower concentrations (10% (w/w) NaCl). The microstructure of the surface of the milled curd was compacted by salt, appearing coarse with 5% (w/w) NaCl or more hydrated with a denser protein structure with 2.5% (w/w) NaCl. After pressing, the curd junctions were fine and thin within the unsalted sample but coarse and thick where 5% (w/w) NaCl was added. Such coarse junctions appear to reduce binding between curd particles leading to a less cohesive cheese. Our results show that NaCl can significantly impact on the structure of fat and protein matrix of the curd surface if salt is not evenly distributed during dry salting. High concentrations of salt can also change the microstructure and texture of the cheese, resulting in a more heterogeneous product.

Surfactant-modified Zn/Al-layered double hydroxides for efficient extraction of alkyl phenols from aqueous samples

Zn/Al-layered double hydroxides (LDHs) modified by sodium dodecylsulfate (SDS) were synthesized as a hydrophobic organic sorbent via urea hydrolysis. LDHs were applied as adsorbent for solid phase extraction (SPE) analysis to determine three alkylphenols (namely, p-tert-amylphenol (PTAP), p-cumylphenol (PCP), and p-n-octylphenol (POP)) in water samples using gas chromatography-mass spectrometry. The extraction efficiency was optimized by adjusting key variables of eluent volume, eluent type, sample flow rate, adsorbent amount, pH, and the effect of salt addition. Under the optimal conditions, APs showed excellent linearity (1–250 ng/mL: R2 > 0.99) and reproducibility (relative standard deviation: <5%). The detection limits for PTAP, PCP, and POP were 19, 16, and 33 pg/mL, respectively. LDHs based SPE method offered high recovery for aqueous samples (e.g., 83.2–99.46%) with enhanced reusability (e.g., up to 10 cycles). The feasibility of the developed method has thus been validated for quantitation of three alkyl phenols (i.e., PTAP, PCP, and POP) in aqueous environmental samples with high sensitivity and good stability.

Combustion synthesis of α-Si3N4 assisted by molten salt additives

Combustion synthesis (CS) of silicon nitride (Si3N4), assisted by molten salt additives under high N2 pressure, is reported. The effect of salt additives (NaCl, MgCl2, and MgCl2∙6H2O) on the reaction temperature and the final α-Si3N4 content is studied. The maximum reaction temperature (Tmax) decreased with an increase in the amount of the salt additives. NaCl is found to be the most suitable as it results in 57.8% α-Si3N4 at 30 mass% concentration. MgCl2 is strongly hygroscopic, and MgCl2∙6H2O decomposes at very low temperature. Therefore, they absorb heat at low temperatures, which makes it difficult to reach the ignition temperature, thereby hindering the reaction propagation. Si3N4 is necessary as a diluent for creating pores in the raw materials to allow effective penetration and contact of N2 gas with the Si particles.

Organizing thermodynamic data obtained from multicomponent polymer electrolytes: Salt‐containing polymer blends and block copolymers

ABSTRACTThe objective of this review is to organize literature data on the thermodynamic properties of salt‐containing polystyrene/poly(ethylene oxide) (PS/PEO) blends and polystyrene‐b‐poly(ethylene oxide) (SEO) diblock copolymers. These systems are of interest due to their potential to serve as electrolytes in all‐solid rechargeable lithium batteries. Mean‐field theories, developed for pure polymer blends and block copolymers, are used to describe phenomenon seen in salt‐containing systems. An effective Flory–Huggins interaction parameter, χeff, that increases linearly with salt concentration is used to describe the effect of salt addition for both blends and block copolymers. Segregation strength, χeffN, where N is the chain length of the homopolymers or block copolymers, is used to map phase behavior of salty systems as a function of composition. Domain spacing of salt‐containing block copolymers is normalized to account for the effect of copolymer composition using an expression obtained in the weak segregation limit. The phase behavior of salty blends, salty block copolymers, and domain spacings of the latter systems, are presented as a function of chain length, composition and salt concentration on universal plots. While the proposed framework has limitations, the universal plots should serve as a starting point for organizing data from other salt‐containing polymer mixtures. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019, 57, 1177–1187

Simultaneous determination of five phthalate esters and bisphenol A in milk by packed-nanofiber solid-phase extraction coupled with gas chromatography and mass spectrometry.

A novel polystyrene/pyridine composite nanofiber was synthesized and utilized as the sorbentmaterial for the solid-phase extraction of bisphenol A and five common phthalate esters in milk. The method of extraction integrated extraction and preconcentration of target analytes into a single step. Bisphenol A and five common phthalate esters were selected as target compounds for the development and evaluation of the method. The effects of operating parameters for nanofiber-based solid-phase extraction, such as selection and amount of sorbent, the volume fraction of perchlorate (precipitate protein), desorption solvent, volume of desorption solvent, and effect of salt addition were optimized. Under optimal conditions, higher extraction recoveries (89.6-118.0%) of the six compounds in milk spiked at three levels were obtained, and the satisfied relative standard deviation were ranged from 0.6 to 10.9%. The detection limits and quantification limits of the method ranged from 0.01 to 0.06μg/L and 0.05 to 0.53μg/L, respectively. Matrix effects were also verified and well controlled in the range of 91.3-109.3%. The new method gave better performance metrics than Chinese standard method and other published methods. Thus, the proposed method may be applied to the analysis of the phthalate esters and bisphenol A in complex matrixes.

A Simple Method for Separating Phenanthrene from Soil by Cloud-Point Extraction

ABSTRACT Contamination of soil by polycyclic aromatic hydrocarbons (PAHs) is currently widespread in urban and industrial areas, and the decontamination of PAHs remains a challenge. In addition, recovering PAHs from large volumes of soil washings is costly. Therefore, in this study, we focused on cloud-point extraction (CPE) without centrifugation, which separates PAHs from the washing solution through gravitational sedimentation. Specifically, we examined the conditions for the separation of phenanthrene (a typical PAH pollutant) from soil using CPE. After evaluating the water and phenanthrene solubilities of 23 commercially available nonionic surfactants, Brij 30 was found to be optimal. We simulated contaminated soil by adding phenanthrene to three soils with different particle sizes and varying amounts of organic matter. We examined the Brij 30 washing conditions and the effects of salt additives that promote phase separation during CPE. The addition of either sodium chloride or sodium sulfate enabled CPE at 25°C, but sodium sulfate was found to be more effective at lower concentrations than sodium chloride. A phenanthrene recovery rate of 58–88% was observed for each laboratory-simulated contaminated soil by CPE using salt additives. This method is economical and effective for processing large amounts of contaminated soil.

Are fungal strains from salinized streams adapted to salt-rich conditions?

Anthropogenic salinization of freshwater is a global problem with largely unknown consequences for stream functions. We compared the effects of salt addition (6 g l-1 NaCl) in microcosms on leaf mass loss and microbial parameters in single- and multispecies assemblages of fungal strains (Heliscus lugdunensis, HELU; Tetracladium marchalianum, TEMA; Flagellospora curta, FLCU) isolated from a reference (R) or salinized (S) stream. Fungal growth and interactions were also assessed. Salinization inhibited leaf decomposition and fungal biomass, but no differences were observed between species, strains or species combinations. Sporulation rates in monocultures were not affected by added salt, but differed among species (FLCU > HELU > TEMA), with S strains releasing more conidia. Fungal assemblages did not differ significantly in total conidia production (either between strains or medium salt concentration). HELU was the dominant species, which also had highest growth and most pronounced antagonistic behaviour. Fungal species, irrespective of origin, largely maintained their function in salinized streams. Strains from salt-contaminated streams did not trade-off conidial production for vegetative growth at high salt levels. The expected reduction of fungal diversity and potential changes in nutritional litter quality owing to salinization may impact leaf incorporation into secondary production in streams.This article is part of the theme issue 'Salt in freshwaters: causes, ecological consequences and future prospects'.

Problems Caused by Moisture in Gas Chromatographic Analysis of Headspace SPME Samples of Short-Chain Amines

Volatile amines are usually problematic compounds in sampling, sample pretreatment and gas chromatographic analysis due to their chemical characteristics (polarity, basicity and reactivity). Headspace solid-phase microextraction (SPME) Arrow sampling of aqueous samples were proven to be complicated since moisture in the headspace was also sorbed into the SPME sorbent and resulted in distorted or split peaks for the volatile amines. This was the case especially with old used sorbents not so much with the new ones. Volume of the water sample, sampling conditions, quality of the SPME sorbent and desorption conditions greatly influenced the concentration of water in the headspace and in the sorbent phase. This, in turn, affected the length of the water film in the column which determined the degree of peak splitting and distance between the split amine peaks (water film trapped part of the amine molecules). Addition of the salt to the sample solution and additional drying of the SPME sorbent after the sampling were shown to effectively decrease the amount of water in the headspace and in the sorbent phase. This combined effect of salt addition and drying step resulted in much better peak shapes and intensities for the amines. In the best cases, the peak splitting for the volatile amines could in this way be completely avoided.

Synthesis of graphene oxide/polyaniline nanocomposite for measuring cadmium(II) by solid phase extraction combined with dispersive liquid-liquid microextraction

An analytical route containing solid-phase extraction combined with dispersive liquid–liquid microextration (SPE–DLLME), was established to determine Cd ions in water samples. In this regard, Graphene oxide/polyaniline nanocomposite was synthesized through chemical method and then the graphene oxide/polyaniline nanocomposite was characterized by using XRD, FESEM, FTIR and TGA techniques. The prepared nanocomposite was investigated as a adsorbent in the presence of chelating dithizone ligand in solid phase extraction with dispersive liquid-liquid microextraction and used to measure cadmium (II) ions in aqueous media. In this method, firstly; single-variable parameters such as the amount of adsorbent, extraction time, type of desorption solvent, desorption time were investigated. Then, with using the design of expert, the parameters affecting the extraction efficiency such as the effect of salt addition (ionic strength), pH, volume of extraction solvent and the volume of dispersive solvent have been optimized. The analytical figure of merit such as limit of detection (0.1 μg L−1), limit of quantification (0.4 μg L−1), linear dynamic ange (0.4–1000 μg L−1), repeatability (%1.3), enrichment factor (210) and relative recovery percentage (99%), were obtained for cadmium (II) spike aqueous samples. Finally, the method was successfully used and evaluated for the extraction and quantification of Cd ions from real samples and relative recoveries varied from 91%–107%.

Ionic Liquids and Organic Ionic Plastic Crystals: Advanced Electrolytes for Safer High Performance Sodium Energy Storage Technologies

AbstractElectrolytes composed entirely of salts, namely, ionic liquid solvents paired with a target ion salt, have been studied extensively within lithium batteries and have recently garnered interest as advanced electrolytes for sodium chemistries. In this review, the unique properties of ionic liquid electrolytes and their solid‐state analogs, organic ionic plastic crystals, are examined. Structure–property relationships, the effect of salt addition, cation and anion functionalization, and their effect upon physicochemical and thermal character are discussed. The authors discuss the use of ionic liquid electrolytes paired with organic solvents (referred to as hybrids) and briefly present the impact of using water as an additive. The majority of the literature presented herein covers studies of sodium electrolytes at Na+ concentrations greater than 50 mol%, labelled as superconcentrated electrolytes, which have recently been investigated for their beneficial device performance and improved target ion mobility. The developing research of ionic liquids toward the oxygen reduction reaction is also presented toward the realization of Na–O2 chemistries to rival that of conventional Li‐ion; gaining fundamental understanding of the active species during discharge, its resultant nucleation and character. Additionally, the properties of the electrode–electrolyte interface resulting from the interaction between typical sodium anodes with ionic liquid electrolytes are discussed.

Development of Dispersive Liquid-Liquid Microextraction method combined with UV spectrophotometry for the Determination of Malathion Pesticide

A simple and novel method was developed by combination of dispersive liquid-liquid microex-traction with UV spectrophotometry for the preconcentartion and determination of trace amount of malathion. The presented method is based on using a small volume of ethylenechloride as the extraction solvent was dissolved in ethanol as the dispersive solvent, then the binary solution was rapidly injected by a syringe into the water sample containing malathion. The important parame-ters, such the type and volume of extraction solvent and disperser solvent, the effect of extraction time and rate, the effect of salt addition and reaction conditions were studied. At the optimum conditions, the calibration graph was linear in the range of 2-100 ng mL-1 of malathion with a limit of detection of 0.8 ng L-1. In addition, the enrichment factor was 30. The developed method was successfully applied for the determination of malathion pesticide in water samples

Fluorescence Quenching of CdTe Quantum Dots with Co (III) Complexes via Electrostatic Assembly Formation

Abstract The photoluminescence quenching of CdTe QDs in the presence of three different Co (III)-complexes is studied to elucidate the role of interactions between functional groups of positively charged cysteamine capped CdTe QDs and negatively charged Co (III) complexes bearing carboxylic groups. The steady state and time resolved spectroscopy has been used to investigate the mechanism of quenching. After detailed analysis, it is concluded that quenching is contributed by both static as well as dynamic processes. The static contribution has been assigned to the electrostatic assembly formation via ionic interactions between the amine functional groups of positively charged cysteamine capped CdTe QDs and carboxylic acid groups of negatively charged complexes. The electrostatic interactions were confirmed by zeta potential measurement as well as from effect of salt addition. These studies have implications in designing donor/acceptor pairs having complementary functional groups for efficient optoelectronic devices or photocatalytic systems.

Gel properties and interactions of Mesona blumes polysaccharide-soy protein isolates mixed gel: The effect of salt addition

Effect of different salt ions on the gel properties and microstructure of Mesona blumes polysaccharide (MBP)-soy protein isolates (SPI) mixed gels were investigated. Sodium and calcium ions were chosen to explore their effects on the rheological behavior and gel properties of MBP-SPI mixed gels were evaluated by using rheological, X-ray diffraction, protein solubility determination, and microstructure analysis. Results showed that the addition of salt ions change the crystalline state of gels system, the crystal of gel was enhanced at low ion concentrations (0.005–0.01 M). The two peaks of gel characteristic at 8.9° and 19.9° almost disappeared at high salt ions concentrations (0.015–0.02 M), and new crystallization peaks appeared at around 30° and 45°. The elasticity, viscosity, gel strength, water holding capacity, and thermal stability of gel were increased at low ion concentration. Results showed that the main interactions which promoted gel formation and maintain the three-dimensional structure of the gel were electrostatic interactions, hydrophobic interactions, and disulfide interactions.

PENGARUH PENAMBAHAN GARAM NaCl PADA LUMPUR PEMBORAN BERBAGAI TEMPERATUR

The unidealized of physical and rheological mud can occured when drilling on rock layers with high salt concentrations. It is therefore necessary to add an additive to balance the effect of the salt. The aims of this study is to see the effect of salt addition on various temperature drilling mud.This research will use two types of mud with different oil-water ratio. The drilling mud will be divided into four compositions, ie LA, LB, LC, and LD. LA and LC compositions have an oil-water ratio of 80% oil and 20% fresh water. While LB and LD compositions have oil-water ratio of 75% oil and 25% fresh water. Then the study was conducted at various temperatures, ie 80 °F, 130 °F, 180 °F, 230 °F, 280 °F, and 330 °F. After observing of the physical properties and rheology of drilling mud, it was found that the effect of adding salt NaCl can improve the physical and rheological properties of mud such as density, viscosity, gel strengh, mud cake, and solid content. Conversely, the effect of adding NaCl salt may reduce the nature of electrical stability. While the increasing of the temperature can reduce the physical and rheological properties of mud and on the contrary the loss of water and mud cake will increase.

Solvate and protic ionic liquids from aza-crown ethers: synthesis, thermal properties, and LCST behavior.

In recent years, solvate and protic ionic liquids (ILs) have attracted much attention. We synthesized both types of ILs from alkyl aza-crown ethers (L = N-propyl-1-aza-15-crown-5 (L1) and N-C6F13C2H4-1-aza-15-crown-5 (L2)). The solvate ILs [ML][Tf2N] (M = Na+, K+) were solids (Tm = 58-68 °C), whereas the solvate ILs [ML][Tf2N] (M = Li+, Ag+) and protic ILs [HL][Tf2N] were liquids with low glass transition temperatures. The ILs containing Na ions were more crystalline and exhibited higher melting points than the other ILs. The decomposition temperatures of the protic ILs were higher than those of the solvate ILs. A protic IL with a paramagnetic anion, [HL1][FeCl4] (Tm = 70.5 °C), was also synthesized and its crystal structure was determined. The solvate ILs [NaL2][X] (X = Cl-, CF3CO2-, TsO-, PhSO3-) exhibited a lower critical solution temperature (LCST)-type behavior in water. The effects of salt addition on the LCST of L2 were also investigated. The LCST of these ILs generally increased with increasing hydrophilicity or basicity of the counter anion. This tendency, which is nearly opposite to that of ILs with quaternary onium cations, is ascribed to the amphiphilic nature of the cation. The corresponding protic ILs did not exhibit LCST behavior.

エリスリトールの過冷却特性に対する塩添加の影響

エリスリトールの過冷却特性に対する塩添加の影響