Effects Of Chemical Interactions Research Articles

Strong synergistic and antagonistic effects of quinones and metal ions in oxidative potential (OP) determination by ascorbic acid (AA) assays

A key challenge in oxidative potential (OP) assays is to accurately assess the cumulative impact of redox-active aerosol species rather than only their individual effects. This study investigates the OP of single and combined mixtures of 1,2-naphthoquinone (1,2-NQ), 1,4-naphthoquinone (1,4-NQ), 9,10-phenanthrenequinone (9,10-PQ), 1,4-benzoquinone (1,4-BQ), Cu, Fe, Mn, and Zn in standard ascorbic acid (OPAA) and the synthetic respiratory tract lining fluid (OPRTLF) assays. In both OPAA and OPRTLF, binary mixtures showed additive and synergistic effects in the presence of 1,2-NQ. The mixture of Cu and Zn showed substantial synergisms in both assays, while the mixtures in the absence of 1,2-NQ primarily induced antagonistic effects. For the first time, we propose linear equations to improve the prediction of OP values by considering the impacts of synergistic and antagonistic effects. Under this approach, we observed that the potential effects caused by binary mixtures in ambient particulate matter (PM) samples could account for up to 68 % of the PM-OP values in Fez, Morocco (OPmAA: 0.34 nmol min−1 µg−1 and OPmRTLF: 0.18 nmol min−1 µg−1). The present study improves the understanding of effects of chemical interaction of potentially toxic substances that are important in the understanding of PM-induced oxidative stress in the human body.

Elucidating the chemical interaction effects of herb pair Danshen-Chuanxiong and its anti-ischemic stroke activities evaluation

Ethnopharmacological relevanceSalvia miltiorrhiza Bunge (Danshen) and Ligusticum chuanxiong Hort. (Chuanxiong) is the core herb pair in traditional Chinese medicines (TCMs) formulae for treating ischemic stroke. However, the synergistic effect of Danshen-Chuanxiong against anti-ischemic stroke and its compatibility mechanism remains unclear. Aim of the studyThis study aimed to uncover the compatibility mechanism of Danshen-Chuanxiong against ischemic stroke through chemical profiling, pharmacodynamics evaluation, network pharmacology and experimental validation. Materials and methodsUltra-high performance liquid chromatography (UHPLC) combined with quadrupole time-of-flight tandem mass spectrometry (QTOF-MS) and UHPLC connected with tandem triple quadrupole mass spectrometry (QQQ-MS) were utilized to conduct the chemical interaction analysis. Then the synergistic effects of Danshen-Chuanxiong against ischemic stroke were comprehensively evaluated by the middle cerebral artery occlusion reperfusion (MCAO/R) mice model, zebrafish ischemic stroke model and glutamic acid-induced PC12 cells injury model. Afterwards, network pharmacology and molecular docking were applied to dissect the significant active compounds and potential mechanisms. Finally, the key target proteins were experimentally validated by Western blot. Results83 compounds were characterized in Danshen-Chuanxiong by UHPLC-QTOF-MS analysis, and 4 compounds were tentatively identified for the first time. The quantification results (24 accurately identified compounds) in 13 proportions of Danshen-Chuanxiong revealed that Danshen significantly increased the dissolution of most phthalides (from Chuanxiong), while Chuanxiong facilitated the dissolution of most phenolic acids (from Danshen) in solution. The anti-ischemic stroke effects of Danshen-Chuanxiong were significantly better than Danshen or Chuanxiong in attenuating infarct size, reducing brain edema and neurological scores in MCAO/R mice. Also, compared with single herbs, this herb pair exerted better effects of suppressing the incidence of cerebral thrombosis in zebrafish, and increasing the cell viability of glutamic acid-induced PC12 cells. In network pharmacology, 7 effective compounds (rosmarinic acid, chlorogenic acid, salvianolic acid B, (Z)-ligustilide, ferulic acid, caffeic acid, tanshinone IIA) and 5 hub targets (AKT, TNF−α, IL-1β, CASP3 and BCL2) as well as 4 key pathways were predicted. Western blot results showed that Danshen-Chuanxiong exert therapeutic effects mainly through decreasing the protein expressions of TNF-α, IL-1β and Cleaved-CASP3, elevating the levels of p-AKT and BCL2. ConclusionsThis work provided an integration strategy for uncovering the synergistic effects and compatibility mechanism of Danshen-Chuanxiong herb pair for treating ischemic stroke, and laid foundation for the further development and utilization of this herb pair.

Combining In Vitro and In Silico New Approach Methods to Investigate Type 3 Iodothyronine Deiodinase Chemical Inhibition Across Species.

New approach methodologies (NAMs) are being developed to reduce and replace vertebrate animal testing in support of ecotoxicology and risk assessment. The US Environmental Protection Agency's Sequence Alignment to Predict Across Species Susceptibility (SeqAPASS) bioinformatic tool was used to evaluate amino acid sequence conservation of the type 3 iodothyronine deiodinase (DIO3) enzyme across species to demonstrate NAM applications for understanding effects of chemical interactions with a specific protein target. Existing literature was used to identify critical amino acids for thyroid hormone binding and interaction with a reducing cofactor. The SeqAPASS tool identifies whether known critical amino acids involved in ligand binding are exact, partial, or not matches across species compared with a template species based on molecular weight and side chain classification. This evaluation guided the design of variant proteins representing critical amino acid substitutions found in various species. Site-directed mutagenesis of the wild-type (WT) human DIO3 gene sequence was used to create six variant proteins expressed in cell culture, which were then tested in vitro for chemical inhibition. Significant differences in in vitro median inhibitory concentration results were observed among variants for potential competitive inhibitors. A molecular model representing the WT human DIO3 was constructed using Molecular Operating Environment (MOE) software and mutated in silico to create the six variants. The MOE Site Finder tool identified the proposed catalytic and cofactor sites and potential alternative binding sites. Virtual docking did not provide affinity scores with sufficient resolution to rank the potency of the chemical inhibitors. Chemical characteristics, function and location of substituted amino acids, and complexities of the protein target are important considerations in developing NAMs to evaluate chemical susceptibility across species. Environ Toxicol Chem 2023;42:1032-1048. © 2023 University of Wisconsin-Madison. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

Review of CO2 sequestration mechanism in saline aquifers

The concentration of CO2 in the global atmosphere, which is increasingly annually with continued industrial development, affects both the global climate and the ecological environment. To control the concentration of atmospheric CO2, various methods of carbon capture and sequestration have been proposed and continue to be developed. Among them, CO2 sequestration in saline aquifers has potential for effective high-capacity carbon storage. This work reviews both the research status of structural, residual, solubility, and mineral CO2 sequestration in saline aquifers, and the research progress associated with the integrity of cement sheaths and caprocks. The findings indicate that structural sequestration research must comprehensively consider the influence of various factors, and that the capacity of structural sequestration must be evaluated based on the actual geological conditions of the saline aquifer, caprock properties, and CO2 injection rate. The heterogeneity of the caprock and dynamic changes of CO2 concentration are not considered in current simulations of the effect of chemical interaction between CO2-rich brine and the caprock. Residual sequestration and solubility sequestration are mutually interactive; therefore, exploration of the residual sequestration mechanism must consider the impact of solubility sequestration. Models for simulation of CO2 solubility sequestration in an entire saline aquifer should be developed to reservoir scale and must consider reservoir heterogeneity.

Molecular Hinges Stabilize Formamidinium‐Based Perovskite Solar Cells with Compressive Strain

AbstractFormamidinium (FA)‐based lead triiodide have emerged as promising light‐harvesting materials for solar cells due to their intriguing optoelectronic properties. However, obstacles to commercialization remain regarding the primary intrinsic materials instability, wherein volatile organic components of FA+ cations are prone to escape under operational stressors. Herein, stabilizing FA‐based perovskite through toughening the interface with the symmetric molecule of 1,1′‐(Methylenedi‐4,1‐phenylene) bismaleimide (BMI) is reported. BMI with two maleimides can simultaneously bind with FA+ and/or undercoordinated Pb2+ through chemical bonding, which also compresses the resultant perovskite lattice. The chemical bonding and strain modulation synergistically not only passivate film defects, but also inhibit perovskite decomposition, thus significantly improving the intrinsic stability of perovskite films. As a result, the BMI‐modified perovskite solar cells (PSCs) show improved power conversion efficiency (PCE) from 21.4% to 22.7% and enhanced long‐term operational stability, maintaining 91.8% of the initial efficiency after 1000 h under continuous maximum power point tracking. The findings shed light on the synergetic effects of chemical interactions and physical regulations, which opens a new avenue for stable and efficient perovskite‐based optoelectronic devices.

Designing dual-confined nanoreactor with built-in small-sized platinum nanoparticles for advanced Li-SeS2 batteries

A dual-confined nanostructured reactor, featured with the small-sized platinum nanoparticles embedded in dendritic mesoporous silica nanospheres with a hierarchical porous graphene-like carbon protection shell, is designed and synthesized as an efficient SeS2 host for high-performance lithium-selenium/sulfur batteries. The rationally designed host framework, which combines the merits of strong chemical interaction effect, abundant catalytic active sites, and excellent conducting network, can realize efficient anchoring and fast conversion of lithium polysulfides/polyselenides during the electrochemical processes. Thus, this SeS2-based cathode shows a high initial capacity of 1013 mAh g−1 at 0.2 A g−1 and an outstanding cycling stability, with a capacity of 426 mAh g−1 over 500 cycles at 2 A g−1, corresponding to a low capacity decay of 0.07% per cycle. This study demonstrates a novel and efficient approach to overcome the hurdles of current lithium-sulfur systems for stable rechargeable batteries.

Quantitative In Vitro-to-In Vivo Extrapolation for Mixtures: A Case Study of Superfund Priority List Pesticides.

In vitro cell-based toxicity testing methods generate large amounts of data informative for risk-based evaluations. To allow extrapolation of the quantitative outputs from cell-based tests to the equivalent exposure levels in humans, reverse toxicokinetic modeling is used to conduct in vitro-to-in vivo extrapolation (IVIVE) from in vitro effective concentrations to in vivo oral dose equivalents. IVIVE modeling approaches for individual chemicals are well-established; however, the potential implications of chemical-to-chemical interactions in mixture settings on IVIVE remain largely unexplored. We hypothesized that chemical coexposures could modulate both protein binding efficiency and hepatocyte clearance of the chemicals in a mixture, which would in turn affect the quantitative IVIVE toxicokinetic parameters. To test this hypothesis, we used 20 pesticides from the Agency for Toxic Substances and Disease Registry Substance Priority List, both individually and as equimolar mixtures, and investigated the concentration-dependent effects of chemical interactions on in vitro toxicokinetic parameters. Plasma protein binding efficiency was determined by using ultracentrifugation, and hepatocyte clearance was estimated in suspensions of cryopreserved primary human hepatocytes. We found that for single chemicals, the protein binding efficiencies were similar at different test concentrations. In a mixture, however, both protein binding efficiency and hepatocyte clearance were affected. When IVIVE was conducted using mixture-derived toxicokinetic data, more conservative estimates of activity-to-exposure ratios were produced as compared with using data from single chemical experiments. Because humans are exposed to mixtures of chemicals, this study is significant as it demonstrates the importance of incorporating mixture-derived parameters into IVIVE for in vitro bioactivity data in order to accurately prioritize risks and facilitate science-based decision-making.

Effect of chemical interaction on solidification of the melts Al-Cu-Ni with 10 at.% NI at low cooling

Effect of chemical interaction on solidification of the melts Al-Cu-Ni with 10 at.% NI at low cooling

Sand failure: effect of biocide on the geomechanical properties of outcrop carbonate rock under static condition

The effects of chemical interaction of a biocide with formation rocks on the rock geomechanical properties are examined. A combination of analytical tests (scanning electron microscopy/energy-dispersive X-ray analysis, X-ray powder diffraction and particle size distribution) and uniaxial compression test was used in this study. The particle size distribution in the effluent showed an increase in D50 with poor sorting for the chemically treated outcrop carbonate core samples. The XRPD shows evidence of altered minerals in the chemically treated samples. It was observed that the interaction led to precipitation of new materials that clogged the pore space of the samples leading to up to 150% increase in compressive strength of the carbonate following treatment with the biocide. The results give more insight into the limitations of existing sand production prediction models with respect to the effect of oilfield chemicals on the strength of the reservoir rocks.

Effect of chemical interaction at modification layer/substrate interface on molecular orientation of dinaphtho[2,3-b:2′,3′-f]thieno[3,2-b]thiophene thin films

The molecular orientation of dinaphtho[2,3-b:2′,3′-f]thieno[3,2-b]thiophene (DNTT) thin films on modified silicon dioxide (SiO2) and copper oxide (CuOx) substrates whose surfaces were treated by 6-[(3-trisilanol)propylamino]-1,3,5-triazine-2,4-bis(2-aminoethylamine) (TAS) was investigated using near-edge X-ray absorption fine structure and ultraviolet/X-ray photoelectron spectroscopy. The standing orientation of DNTT was obtained in DNTT/TAS/SiO2 and DNTT/TAS/CuOx. The amount of amorphous region in DNTT/TAS/SiO2 was larger than that in DNTT/TAS/CuOx. The TAS treatment on the substrates formed interfacial dipoles at TAS/SiO2 and TAS/CuOx interfaces by chemical interaction, resulting in the vacuum level shift by −0.9 and −1.2 eV, respectively. Functional groups at the outermost TAS surface were amino groups in TAS/SiO2 and silanol groups in TAS/CuOx. The intermolecular distance of DNTT was widened in DNTT/TAS/SiO2 because of an electrostatic repulsion with nitrogen. The interfacial dipole at the modification layer/substrate interface and functional groups at the modified surface affect the molecular orientation of DNTT thin films on the modification layer.

Effect of hydrogen enrichment of laminar ethylene diffusion flames on thermal structure and soot yields at pressures up to 10 bar

A series of high-pressure experiments were conducted to assess the influence of hydrogen enrichment of laminar diffusion flames of nitrogen-diluted ethylene on the thermal flame structure and soot yields at pressures above atmospheric. In parallel experiments, added hydrogen is replaced by helium, either in equal mole fractions or in mass fractions, to evaluate the thermal, dilution, and direct chemical interaction effects of hydrogen in soot formation. Experiments covered pressures from atmospheric to 10 bar. In the first set of experiments, conducted at 3, 6, and 10 bar pressure, base fuel was an ethylene-nitrogen mixture with 33.3% ethylene and 66.7% nitrogen (by mole as well as by mass). This base fuel was doped with either hydrogen or helium such that hydrogen and helium mass fractions and mole fractions in the fuel stream are matched in two cases. In the second set of experiments, which were conducted at 1.2 bar pressure with ethylene as the base fuel, hydrogen or helium is added such that additive mole fraction in the fuel stream was 44%. Temperature measurements in the first set of experiments indicate that, when hydrogen is added to nitrogen-diluted ethylene, the changes in the temperature field of the co-flow diffusion flames are negligible, except at lower in the flame where hydrogen added flames display slightly higher temperatures. When helium is added instead of hydrogen, however, the temperatures were measurably lower than those of the base fuel. Results show that, once the dilution effects are accounted for, the hydrogen addition to ethylene does not suppress soot formation by direct chemical interaction at elevated pressures. These findings, which are not in agreement with the previous experimental results obtained at atmospheric pressure, are discussed in terms of the higher molecular diffusivity of hydrogen and shorter residence times of high-pressure flames.

Effects of chemical interaction of nutrients and EDTA on metals toxicity to Pseudokirckneriella subcapitata

We studied the effect of the chemical interaction of nutrients and the ethylenediamine tetraacetic acid (EDTA) on metals toxicity. Growth inhibition tests of Pseudokirchneriella subcapitata by nutrient metals copper (Cu) and zinc (Zn), and the non-nutrient metal lead (Pb), were performed. The high-enriched Bold's Basal medium (BBm) and two low-enriched standard media, recommended by the Organization for Economic Cooperation and Development (OECDm) and Environmental Protection Agency-algal assay procedure medium (AAPm), were used in this study. The metals toxicity was affected by the interaction of nutrients and EDTA. Cu+2 was more toxic in the OECDm (EC50 20.3 μg/L), while Pb+2 (EC50 23.1 μg/L) and Zn+2 (EC50 99.4 μg/L) in the AAPm. Non-toxic effect of these metals was observed in BBm, but the exclusion of EDTA shifted it into a toxic medium. Finally, we found that the toxicity of the studied nutrient metals is mainly influenced by EDTA, which reduced the concentration of ionized metals, while the toxicity of the non-nutrient metal is affected by EDTA and phosphates.

The effect of chemical interaction on the morphology of metal-carbon composites formed in a graphite arc

This work deals with the analysis of mechanism of nanostructured composite formation at joint electric-arc spraying of graphite electrodes with addition of various elements. It is shown that the morphology of nanoparticles, formed at condensation of carbon vapors with the additive elements that have similar pressures of saturated vapors, can vary significantly. This difference is explained by chemical interaction of an additive element with the carbon matrix.

A ZIF-67-derived–sulfur sandwich structure for high performance Li–S batteries

Herein, a novel ZIF-67-derived material, PZ67, is developed as an effective coating to construct a sandwich-structured electrode for high performance lithium sulfur batteries. Taking advantage of the synergistic effect of chemical interaction, physical barrier, and high conductivity of PZ67 coatings, we found that the PZ67/S/PZ67 structured cathode can effectively enhance the active materials reaction kinetics, prohibit the shuttling effect, and improve the batteries’ cycling performance, achieving a superior electrochemical performance. It delivers an initial capacity of 1158.1 mA h g−1 and retains at 715 mA h g−1 after 300 cycles, which is more than twice of that of a bare sulfur-based cell. Even at the current density of 1 C, the discharge capacity still approaches 916.7 mA h g−1.

Influence of vacuum annealing on the photoresponse of thermally evaporated cadmium telluride thin films

Post-deposition annealing of thin films can induce significant changes in their properties. Annealing in vacuum is particularly important because it elucidates the influence of thermal energy rather than the effects of chemical interactions with a specific ambient. Cadmium telluride (CdTe) is one of the most promising materials for photovoltaic applications. Annealing in cadmium chloride has been established as the standard method to activate the efficiency of CdTe. Nevertheless, annealing CdTe in vacuum was rarely investigated. In this work, CdTe thin films were grown by thermal evaporation, and subsequently subjected to annealing in vacuum. The resulting changes in the structural, chemical, optical, and photoelectric properties of the films were investigated. Annealing caused substantial changes in the crystallinity, surface morphology, surface chemical composition, light absorption, photocurrent and photoresponse of the films.

AgNP/crystalline PANI/EBP‐composite‐based supercapacitor electrode with internal chemical interactions

ABSTRACTIn this article, polyaniline (PANI) was conformally coated on epoxide‐functionalized buckypaper (EBP). Because of the presence of epoxide functional groups, chemical interactions occurred between oxygen in the epoxide groups and NH in the PANI. These chemical interactions were identified by peak shifts and intensity changes in Raman spectra. Additionally, crystalline peaks were clearly observed through X‐ray diffraction. However, Raman peak changes or crystalline peaks were not observed in nonfunctionalized buckypaper (purified pristine buckypaper [PPBP])‐based composites. Both hydrogen bonding and crystalline nature of EBP‐PANI enhanced its electrical conductivity, producing a specific capacitance better than that of PPBP‐PANI. Finally, Ag nanoparticles (AgNPs) were applied to EBP‐PANI to further enhance its electrical conductivity. Owing to the presence of AgNPs and their interactions with the N in PANI, the specific capacitance of EBP‐PANI‐AgNP reached 915.62 F/g. These results emphasize the positive effect of chemical interactions and crystalline nature of EBP‐based composites on their electrochemical performance. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48164.

Low to intermediate temperature oxidation studies of dimethoxymethane/n-heptane blends in a jet-stirred reactor

Kinetic research concerning fuel blends of ethers or dithers and larger alkanes at low temperatures is extremely scarce. In this work, a study of the oxidation of dimethoxymethane (DMM)/n-heptane fuel blends (neat n-heptane, 25/75, 50/50, neat DMM) was performed using an atmospheric pressure jet-stirred reactor over the temperature range of 500–1100 K, at a residence time of 2.0 s, at three equivalence ratios (0.5, 1.0, and 2.0), and at a constant fuel inlet mole fraction of 0.005 (with high dilution in argon). The reliability of the newly built JSR setup was validated against literature data. A chemical kinetic model capable of describing the low temperature chemistry of the fuel blends was constructed. The effect of using AramcoMech 1.3 and AramcoMech 2.0, respectively, as the base-mechanism has been tested and some important reactions such as Ḣ +O2 (+M) <=> HȮ2 (+M), have been found to be responsible for their different performances. Not unexpectedly, the reactivity of DMM is remarkably enhanced in the fuel blends and correspondingly, that of n-heptane is inhibited. To quantify the degree to which the reactivity of n-heptane is inhibited, an inhibiting coefficient was introduced. It is interesting that the correlation between the inhibiting intensity and equivalence ratio is non-monotonic. Rate of production analysis was conducted to investigate the chemical interaction effect on their respective decomposition pathways at lower temperatures. Kinetic analysis combined with the experimental observations indicate that the rate coefficients for H-abstraction reactions by ȮH from DMM were overestimated. Possible modifications to the reaction rate of this reaction type were suggested, leading to a better prediction. Three intermediate representatives were discussed in detail to elucidate the chemical interactions between the two fuel components.

Crosslinking induced photoluminescence quenching in polyvinyl alcohol-carbon quantum dot composite

Highly luminescent and water-soluble carbon quantum dots (CQDs) have been integrated into polyvinyl alcohol (PVA) recently to realize composites with synergistic functionalities. The effects of chemical interactions between CQDs and PVA matrix on the changes in optical properties of CQDs or physicochemical properties of PVA are yet to be investigated fully. Herein, we first synthesized CQDs with different surface chemistry via varying the molar ratio between citric acid (CA) and ethylenediamine and then embedded the CQDs into PVA with or without additional CA crosslinking. Infrared and UV–vis studies on CQDs and composites showed that condensation between CQDs and PVA induced a redshift in the absorption peak originating from CQDs’ surface fluorophore groups. Interestingly, CA crosslinking significantly increased the water resistance, but it quenched the photoluminescence of composites. The quenching effects were reduced by using CQDs having less reactivity with CA.

Effect of chemical interaction between oleic acid and L-Arginine on oral perception, as a function of polymorphisms of CD36 and OBPIIa and genetic ability to taste 6-n-propylthiouracil.

Oral sensitivity to fats varies in individuals influencing nutritional status and health. Variations in oleic acid perception are associated with CD36 and odorant binding protein (OBPIIa) polymorphisms, and 6-n-propylthiouracil (PROP) sensitivity, which is mediated by TAS2R38 receptor. L-Arginine (L-Arg) supplementation was shown to modify the perception of the five taste qualities. Here we analyzed the effect of three concentrations (5, 10, 15 mmol/L) of L-Arg on oral perception of oleic acid in forty-six subjects classified for PROP taster status and genotyped for TAS2R38, CD36 and OBPIIa polymorphisms. L-Arg supplementation was effective in increasing the perceived intensity of oleic acid in most subjects. The lowest concentration was the most effective, especially in PROP non-tasters or medium tasters, and in subjects with at least an allele A in CD36 and OBPIIa loci. Density Functional Theory (DFT) calculations were exploited to characterize the chemical interaction between L-Arg and oleic acid, showing that a stable 1:1 oleate·ArgH+ adduct can be formed, stabilized by a pair of hydrogen bonds. Results indicate that L-Arg, acting as a ‘carrier’ of fatty acids in saliva, can selectively modify taste response, and suggest that it may to be used in personalized dietetic strategies to optimize eating behaviors and health.

Kinetic study of Ni(II) removal using ion flotation: Effect of chemical interactions

In this kinetic study, the separation mechanism and chemical interactions of Ni(II) ion removal from synthetic wastewater were evaluated by ion flotation. The influence of effective factors such as pH, collector concentration, ionic strength, activity coefficient, foreign salts, and gas type were also evaluated on the kinetics of Ni(II) ion removal and water removal during the process. By increasing pH, the Ni(II) removal rate increased, in which foam fractionation occurred at pH levels of 3, 5.5, and 8 and ion flotation at a pH level of 9.7. The difference between foam fractionation and ion flotation is related to the flotation of a soluble or insoluble complex of the ion–collector. The kinetic study was also used to determine the separation mechanism. The order of Ni(II) foam fractionation was two, while the order of Ni(II) ion flotation was one. The Ni(II) removal rate was faster than the water removal rate, which indicated that Ni(II) ion removal was carried out by true flotation. The effect of chemical interactions on the characterization of the sublate (insoluble complexes formed in the scum layer) were studied using scanning electron microscopy coupled with energy dispersive X-ray (SEM/EDX) spectroscopy and Fourier transform infrared (FTIR) spectroscopy. The results showed that the chemical conditions have an important effect on the Ni(II) ion flotation efficiency.