Acid Concentration Ratio Research Articles

Computational mining of a novel Acetyl‐CoA synthetase for the biosynthesis of unnatural Phenylalanine butyramide

Phenylalanine butyramide (FBA) is an unnatural amide with the potential to be a postbiotic derivative due to its improved organoleptic and physicochemical properties compared to butyric acid and salts. However, a green biosynthesis method to prepare FBA has not been studied to date. In this study, we mined a novel Acetyl‐CoA synthetase from Methanocella arvoryzae (MethACS) for the synthesis of FBA using a sequence and structure‐guided database mining approach that combines solubility prediction with binding free energy of the protein. MethACS exhibits excellent catalytic performance, pH stability, and good thermophilicity. 0.35 g/L FBA could be produced by MethACS with a 100% conversion rate when the concentration ratio of butyric acid to phenylalaninamide was >1:4. Through density‐functional theory calculations and molecular dynamics simulation, we gained insight into the mechanism of the synthesis of FBA catalyzed by MethACS. Trp264 was further identified as a crucial residue influencing the substrate specificity by saturation mutagenesis. Substrate profiling revealed that MethACS can catalyze the formation of amide derivatives of short‐ and medium‐chain fatty acids. This study offers an efficient approach for investigating the biosynthesis of unnatural substances.

Investigation on the effect of operational parameters in a microreactor system on the morphology and size distribution of thorium oxalate

Thorium oxide has recently garnered attention as a nuclear fuel due to the scarcity of uranium resources and the abundance of thorium resources, as well as its favorable thermal and neutronic properties. One of the most desirable characteristics of thorium nuclear fuels is their thermal properties, which are affected by the size distribution and morphology of thorium oxide particles. Thorium nitrate is the most common method for producing thorium oxide. Since no purification processes occur in the production of thorium oxide from oxalates, particle size and shape control are crucial. In this paper, the synthesis of thorium oxalate particles is carried out in a microreactor system to control the parameters of the precipitates. The main parameters that influence the efficiency, size distribution, and morphology of thorium oxalate are the concentration ratio of oxalic acid to thorium nitrate solution, as well as the flow rate ratio of these feed materials. Results show that at lower flow rate ratios of thorium nitrate to oxalic acid solution and higher concentration ratios of acid to thorium nitrate solution, a uniform particle size distribution and smaller particles are obtained, which are suitable for further calcination to prepare high-density and small grain size pellets.

Association of plasma arachidonic acid levels with a bipolar disorder and the effects of a FADS gene variant

Recent genome-wide association studies (GWASs) have identified fatty acid desaturase (FADS) genes, which code key enzymes involved in polyunsaturated fatty acid (PUFA) desaturation as susceptibility genes for bipolar disorder (BD). Several quantitative changes in PUFAs suggest their involvement in BD pathogenesis. Therefore, this study aimed to clarify the relationship between BD and PUFAs by conducting lipidomics covariating with the FADS gene variant (rs174550), which is associated with PUFA levels and BD susceptibility. The concentrations of 23 fatty acids were measured using plasma samples from the BD group (n = 535) and the control group (n = 107). Differences in each PUFA concentration ratio were compared between the two groups. Also, differences in each PUFA concentration ratio were compared for each genotype in rs174550. Our results showed that the BD group had significantly lower concentrations of linoleic acid (LA) (β = −0.36, p = 0.023) and arachidonic acid (AA) (β = −0.18, p = 0.013) than the control group. Concerning the effect of FADS on the PUFA concentration ratio, carriers of C-allele at rs174550 had significantly decreased γ-linolenic acid and AA concentration ratios. A previous GWAS reported that the presence of a C-allele at rs174550 increased the BD risk. This direction is consistent with the lipidomic results of the present study. In conclusion, both the FADS and BD were considered to regulate the AA concentration. Thus, as the FADS gene variant is crucial for conducting lipidomics of BD we believe that the allele frequency of FADS must be analyzed.

Anodization of cast and sintered Fe40Al alloy in etidronic acid: Morphological and semiconductive properties of the oxide films

Fe40Al alloys produced by casting and sintering were anodized to form nanostructured oxide layers. Microstructural characterization revealed a lower grain size for the sintered alloy compared to the cast alloy. Anodizing was performed in four electrolytes with a constant etidronic acid concentration (0.3 M) and different ethylene glycol-water ratios. Different voltages (5–400 V) and treatment times (1–4 hours) were evaluated for cast and sintered Fe40Al alloys. Among the studied anodization regimes, only four anodic films formed on sintered Fe40Al were homogeneous. These films were annealed at 900°C and analyzed by conventional characterization techniques (SEM/EDS and XRD). Results indicated a non-self-ordered morphology and different content of P, Fe, and Al species as a function of the electrolyte composition. Annealing post-treatment led to the formation of Fe/Al oxides and spinels in selected anodic films. An additional peak of FePO4 was detected only in the anodic film formed in pure ethylene glycol. The band gap values (UV-Vis reflectance spectroscopy) of the anodic film formed in ethylene glycol decreased from 2.87 eV to 2.45 eV after annealing. This band gap decrease was associated with the preferential formation of conductive phases (Fe2O3 and FeAlO3) over insulating phases (γ-Al2O3 and FeAl2O4) after annealing.

Anthropogenic sources and liquid water drive secondary organic aerosol formation over the eastern Himalaya

Atmospheric aerosols have a serious impact on altering the radiation balance of the vulnerable Himalayan atmosphere. Organic aerosol (OA), one of the least resolved aerosol fractions in the Himalayas, constrain our competence to assess their climate impacts on the region. Here we investigate water-soluble OA molecules in PM10 samples collected from March to May 2019 at Lachung (27.4°N and 88.4°E), a high-altitude location (2700 m a.s.l.) in the eastern Himalaya, to elucidate their origin and formation process. The dominance of oxalic acid (C2) reveals that water-soluble OA in the eastern Himalaya are atmospherically processed. Backward air mass trajectories and mass concentration ratios of organic tracers as well as relationships with inorganic species (K+, SO42−, NH4+) suggest an anthropogenic origin of water-soluble OA with significant atmospheric processing during long-range transport to the eastern Himalayan region. We used the thermodynamic prediction of aerosol liquid water (ALW) to examine the formation mechanism of secondary OA (SOA) such as oxalic acid. Correlations of ALW with SO42− and water-soluble organic matter show that ALW is sensitive to both anthropogenic sulfate and water-soluble organic compounds in Himalayan aerosols. A strong positive relationship of C2 acid with predicted ALW provides evidence of extensive SOA formation from precursors via aqueous phase photochemical processes. This inference is supported by positive correlations of C2 acid relative abundance with diagnostic mass concentration ratios of C2 acid to precursor molecules. Our findings underscore the importance of anthropogenic sources and ALW in SOA formation through aqueous phase processes in the eastern Himalaya.

Effect ratio of stearic acid and oleic acid on characteristics of diclofenac sodium nanostructured lipid carrier

Background: Osteoarthritis treatment generally involves using a Non-steroidal Anti-inflammatory Drug (NSAID), and the most common is Diclofenac sodium. The oral use of diclofenac sodium presents some adverse effects on the gastrointestinal tract. Trans-dermal diclofenac sodium's biological efficacy can be affected by factors including its log P value of 1.13. Nanostructured Lipid Carrier (NLC) may solve these concerns. Objective: This study examined how stearic and oleic acid concentrations customise diclofenac sodium NLC's physicochemical properties. Method: High shear homogenisation was used to compare stearic acid and oleic acid at 6:4, 7:3, and 8:2. Furthermore, the physicochemical properties of diclofenac sodium NLC were assessed, such as organoleptic, particle size and poly-dispersity index, pH, viscosity, zeta potential, entrapment efficiency, profiles of FTIR and DSC. Result: This study found that particle size ranged from 333.60 ± 144.29 to 791.77 ± 85.57, and entrapment efficiency was 89.38 ± 3.69 to 76.96 ± 3.29. Increasing the content of oleic acid as a liquid lipid reduces particle size and improves diclofenac sodium NLC entrapment. According to One-Way ANOVA, the dependent variable was not significantly affected by any independent variables (p-value > 0.05) except for particle size and entrapment efficiency. Conclusion: Stearic acid-oleic acid concentration ratios affect diclofenac sodium NLC's physicochemical properties.

Efficient synthesis of L-malic acid by malic enzyme biocatalysis with CO2 fixation

The malic enzyme (ME) catalyzes the synthesis of L-malic acid (L-MA) from pyruvic acid and CO2 with NADH as the reverse reaction of L-MA decarboxylation. Carboxylation requires excess pyruvic acid, limiting its application. In this study, it was determined that CO2 was the carboxyl donor by parsing the effects of HCO3– and CO2, which provided a basis for improving the L-MA yield. Moreover, the concentration ratio of pyruvic acid to NADH was reduced from 70:1 to 5:1 using CO2 to inhibit decarboxylation and to introduce the ME mutant A464S with a 2-fold lower Km than that of the wild type. Finally, carboxylation was coupled with NADH regeneration, resulting in a maximum L-MA yield of 77 % based on the initial concentration of pyruvic acid. Strategic modifications, including optimal reactant ratios and efficient mutant ME, significantly enhanced L-MA synthesis from CO2, providing a promising approach to the biotransformation process.

Fingerprinting of monovarietal olive oils from Argentina and Uruguay via stable isotope, fatty acid profile, and chemometric analyses

Tracing methods of non-European EVOOs commercialized worldwide are becoming crucial for effective authenticity controls. Limited analytical studies of these oils are available on a global scale, similar to those of European EVOOs. We report for the first time the fatty acid concentrations, bulk-oil 2H/1H, 13C/12C, and 18O/16O ratios and fatty acid 13C/12C ratios of 43 authentic monovarietal EVOOs from different geographical regions in Argentina and Uruguay. The samples were obtained from a wide range of latitudes and altitudes along an E–W profile, from lowlands near the Atlantic Ocean to the pre-Andean highlands near the Pacific Ocean. Principal component scores were used to cluster EVOOs into three groups— central-western Argentina, central Argentina, and Uruguay—based on nine stable isotope ratios and the oleic-linoleic acid concentration ratio. The bulk 2H/1H and 18O/16O values and 13C/12C of palmitoleic and linoleic acids provide good tools for differentiating these oils via linear discriminant analysis.

Plasma bile acids in association with Crohn’s disease

Background In addition to facilitating lipid digestions, bile acids (BA) are signalling molecules acting on receptors on immune cells and along the gastrointestinal (GI) tract. The aim of this study was to assess if altered bile acid profiles in plasma are associated with Crohn’s disease (CD). Method This cross-sectional study included individuals (aged ≥18 years) referred for colonoscopy at a tertiary centre in Stockholm between 2016 and 2019. All participants received bowel preparation, completed a lifestyle questionnaire and provided blood samples for analysis. During colonoscopy, severity of disease was graded, and biopsies were taken from colonic mucosa. In the current substudy, 88 individuals with CD and 88 age-matched controls were selected for analysis of BA in plasma with ultra performance liquid chromatography (UPLC). Linear regression models were then used to compare mean bile acid concentrations and concentration ratios between CD and controls. Results Individuals with CD had lower plasma concentrations of the majority of secondary BA compared to controls, in total CD/CC ratio 0.60 (SE 0.12), p = 0.001. The most prominent observations were lower levels of deoxycolic acid derivates and lithocolic acid derivates among participants with CD. Moreover, plasma concentration for secondary BA among participants with active CD was significantly lower compared to those with CD in remission, CD active/CD remission ratio 0.65 (SE 0.11), p < 0.002. Conclusion Crohn’s disease may be associated with altered plasma bile acid composition. The significance of colonic bacterial diversity in this context needs to be investigated in further studies.

Predicting skin permeation-enhancing effect of fixed oils using saturated to unsaturated fatty acid ratio content

Background: Transdermal drug delivery is non-invasive and advantageous as it improves patient compliance.&#x0D; Objective: This study evaluated the effect of varying ratios of saturated to unsaturated fatty acids in fixed oils on the permeation of ibuprofen across pig dorsal skin.&#x0D; Methods: The solubility of ibuprofen in soybean oil, theobroma oil, and shea butter (fixed oils) was evaluated and in vitro skin permeation studies were conducted using Franz diffusion cells.&#x0D; Results: A significant difference in permeability parameters, such as flux and effective skin permeability, in the different formulations was observed. Skin permeation depended on the ratio of saturated to unsaturated fatty acids. It also depended on the type and concentration of individual saturated and unsaturated fatty acids present in the fixed oils. The skin permeation of ibuprofen increased with an increasing ratio of palmitic acid (PA) to oleic acid (OA) concentrations. The highest flux was obtained in the theobroma oil formulation, with a PA:OA ratio of 0.78. The lowest flux was obtained in the shea butter formulation, with a PA:OA ratio of 0.09. The PA:OA ratio was 0.46 in the soybean oil formulation.&#x0D; Conclusion: These results suggest that the ratio of saturated to unsaturated fatty acids in fixed oils could be used as a model for predicting the rate of skin permeation of drugs in oil-based formulations. Depending on the desired rate of drug permeation, different combinations of the ratio of saturated to unsaturated fatty acids can be used in formulations for transdermal delivery.

Low current density electropolishing and corrosion resistance study of 304 stainless steel

In response to the challenge posed by electrical breakdown occurrences during the conventional current density electrolytic polishing of large-scale stainless steel workpieces, this investigation delved into the parameters of low current density electrolytic polishing process. The study scrutinised the surface morphology and corrosion resistance of 304 stainless steel, employing tools such as metallographic microscopy, a roughness gauge, and an electrochemical workstation. Within a sulphuric acid–phosphoric acid-based electrolyte characterised by a volume ratio of 1:2, the optimal mass concentration ratio of salicylic acid and saccharin was ascertained to be 3:3. By configuring the process parameters to 10 A dm−2 and 20 min, outcomes of electrolytic polishing were obtained that stood on par with the conventional current density approach. The stainless steel surface exhibited a surface roughness measuring a mere 0.08 µm and characterised by a corrosion current density of 1.907 × 10−8 A cm−2 and a corrosion potential of −0.0965 V.

Synthesis and Characterization of Nanoherbal of Reed Root Ethanol Extract (Imperata cylindrica L) Using Ionic Gelation Method

The purpose of this study was to determine the characteristics of nanoherbal of reed root ethanol extract (Imperata cylindrica L) and optimal variations of alginate and CaCl2 for the manufacture of nanoherbal of reed root ethanol extract. Nanoherbal are made using the ionic gelation method by mixing ethanol extract of reed root, alginate solution, and CaCl2 solution. There are three variations in the composition of alginate and CaCl2 solutions used, namely the ratio of 1: 6.66, 1: 3.33 and 1: 2.5. The solids in the nanoherbal colloids are separated using centrifuges. The residue is washed with aqueous and freeze dryer for 24 hours. Colloidal nanoherbal were characterized using PSA to determine particle size and potential zeta values. Nanoherbal solids were characterized using SEM to determine their surface morphological shape. The nanoherbal that were successfully made were faded yellow and white solids. The IR spectrum of nanoherbal shows absorption bands at O-H extended vibrations, C-O bending vibrations, and C=C bending vibrations that undergo shifting, as well as the emergence of manuronat fingerprint bond vibrations in the infrared spectrum supporting the formation of nanoherbal. Characterization using PSA showed a size of 186.2 nm at an optimal concentration ratio of alginic acid and CaCl2 of 1:6.66. SEM results show solids particles are not spherical, uneven, and in the form of loose aggregates on the surface.

Paired Liver:Plasma PFAS Concentration Ratios from Adolescents in the Teen-LABS Study and Derivation of Empirical and Mass Balance Models to Predict and Explain Liver PFAS Accumulation.

Animal studies have pointed at the liver as a hotspot for per- and polyfluoroalkyl substances (PFAS) accumulation and toxicity; however, these findings have not been replicated in human populations. We measured concentrations of seven PFAS in matched liver and plasma samples collected at the time of bariatric surgery from 64 adolescents in the Teen-Longitudinal Assessment of Bariatric Surgery (Teen-LABS) study. Liver:plasma concentration ratios were perfectly explained (r2 > 0.99) in a multilinear regression (MLR) model based on toxicokinetic (TK) descriptors consisting of binding to tissue constituents and membrane permeabilities. Of the seven matched plasma and liver PFAS concentrations compared in this study, the liver:plasma concentration ratio of perfluoroheptanoic acid (PFHpA) was considerably higher than the liver:plasma concentration ratio of other PFAS congeners. Comparing the MLR model with an equilibrium mass balance model (MBM) suggested that complex kinetic transport processes are driving the unexpectedly high liver:plasma concentration ratio of PFHpA. Intratissue MBM modeling pointed to membrane lipids as the tissue constituents that drive the liver accumulation of long-chain, hydrophobic PFAS, whereas albumin binding of hydrophobic PFAS dominated PFAS distribution in plasma. The liver:plasma concentration data set, empirical MLR model, and mechanistic MBM modeling allow the prediction of liver from plasma concentrations measured in human cohort studies. Our study demonstrates that combining biomonitoring data with mechanistic modeling can identify underlying mechanisms of internal distribution and specific target organ toxicity of PFAS in humans.

Reliable Identification of Relevant Factors for the Reactive Extraction of Succinic Acid from Electrolyte Containing Solutions

ABSTRACT Reactive extraction of succinic acid by tertiary amines is an effective separation technique. Its potential application for the initial recovery of bio-based succinic acid from fermentation broth. However, the co-extraction of inorganic anions significantly impairs the extraction performance. In this study, we use a statistically backed design of experiments method (DoE) to screen and identify the factors with a significant effect and relevant impact on extraction yield and selectivity. Eight operational factors (Extractant, solvent, succinic acid concentration, amine concentration, initial pH, the type of anion, electrolyte concentration, and temperature) were screened by applying an orthogonal design plan for the experiments. The choice of the extractant and diluent as well as the type of anion had the most significant effect on the extraction yield. In contrast, the selectivity was mainly affected by the concentration ratios of succinic acid and electrolyte. The screening plan reduced the number of experiments from 1728 possible combinations to 72 experiments required to identify the factors while maintaining the significance of the identified effects. We suggest competing mass-action relationships between the pH-dependent protonation of amines and the complexation of succinic acid to explain the observed trends.

Thermal Transformations of Porous Anodic Aluminum Oxide Formed in Sulfuric Acid/Oxalic Acid Mixed Electrolytes

Aluminum anodizing in electrolytes comprising mixtures of several acids opens way to manufacture porous films of anodic aluminum oxide (AAO) with a widely tunable structure period. Study of thermal transformations in AAO films produced in mixed electrolytes is a separate task, as a complex chemical composition of the material can give rise to some specifics in subsequent annealing. Impurity oxalate and sulfate ions were detected in the AAO produced by aluminum anodizing in sulfuric acid/oxalic acid mixed electrolytes. The sulfate weight fraction appears about one order of magnitude higher than the oxalate weight fraction, and it increases as the concentration ratio of sulfuric acid to oxalic acid in the electrolyte increases. In the same way, the crystallization temperature of amorphous AAO to a mixture of low-temperature Al2O3 polymorphs increases in response to increasing concentration ratio of sulfuric acid and oxalic acid. Thus, the component ratio in the mixed electrolyte used influences the composition and thermal transformations of AAO.

Purification of crude terephthalic acid using phosphomolybdic acid supported on MCM-41 and TiO2 photocatalysts

The present research introduces the photocatalytic process for the conversion of 4-carboxybenzaldehyde to terephthalic acid through the synthesis of phosphomolybdic acid (PMo) supported on TiO2 and MCM-41 as the new class of photocatalysts for this application. As synthesized photocatalysts were characterized through XRD, FT-IR, N2 adsorption–desorption, and FESEM-EDS. It was found that the maximum conversion of 4-carboxybenzaldehyde to para-toluic acid was achieved by 25% PMo/TiO2 photocatalyst with a value of 97.85%. To investigate the effect of parameters such as UV irradiation power intensity, temperature, catalyst dosage, and persulfate concentration, Response Surface Methodology (RSM) was used. Finally, the experimental results showed the UV irradiation power intensity of 2.3 W/mL, the temperature of 24 °C, and the concentration ratio of terephthalic acid to persulfate and catalyst of 3.1 mg/mg and 7.2 mg/mg, respectively as the optimum values. At this operating condition, the concentration of 4-carboxybenzaldehyde decreased from 1870 ppm to 40.2 ppm after 90 min.

Kinetics and mechanism of manganese reductive leaching from electrolytic manganese anode slag with elemental sulfur in sulfuric acid solution

Recycling EMAS in an eco-friendly manner is crucial to alleviate the demand for manganese resource and reduce environmental pollution. Hydrometallurgical reductive leaching of EMAS with elemental sulfur is proposed, but sulfur is chemically inert. To improve the rate and degree of reductive dissolution of EMAS using elemental sulfur. Reductive leaching kinetics of EMAS by elemental sulfur with the aid of H2SO4 at atmospheric pressure have been conducted. A shrinking core model was used to explain the leaching data obtained, and the apparent activation energy was determined to be 63.8 kJ mol−1, indicating the leaching was controlled by chemical reation. The reaction order with respect to sulfuric acid concentration and mass ratio of sulfur to EMAS were 2.6 and 0.9, respectively. The leaching rate equation was established based on the shrinking core model, and good agreement between experimental data and predicted rate curves was obtained. Mechanism of reductive leaching was reasonably speculated with the assistance of X-ray diffraction and scanning electron microscope, revealing that the manganese reduction and sulfur oxidation progressed step by step, following the order Mn4+→Mn3+→Mn2+ and S0→S1+→S2+→ S4+→S6+. The ring opening reaction of [S8]•+ was identified as the rate-determining step. The results of this research provide a theoretical guidance for improving the speed and degree of manganese reduction leaching.

Functional Characteristics of Whey Protein-Derived Peptides Produced Using Lactic Acid Bacteria Hydrolysis

Hydrolysis of whey-derived proteins using lactic acid bacteria (LAB) utilizes the mass culture method and fermentation of LAB to produce effective bioactive peptides. Whey protein has the biological potential of its precursors, but the active fragments may not be released depending on the hydrolysis method. As an alternative to these problems, the nutritional and bioactive functionality of the hydrolysis method have been reported to be improved using LAB for whey protein. Peptide fractions were obtained using a sample fast protein liquid chromatography device. Antioxidant activity was verified for each of the five fractions obtained. In vitro cell experiments showed no cytotoxicity and inhibited nitric oxide production. Cytokine (IL [interleukin]-1α, IL-6, tumor necrosis factor-α) production was significantly lower than that of lipopolysaccharides (+). As a result of checking the amino acid content ratio of the fractions selected through the AccQ-Tag system, 17 types of amino acids were identified, and the content of isoleucine, an essential amino acid, was the highest. These properties show their applicability for the production of functional products utilizing dietary supplements and milk. It can be presented as an efficient method in terms of product functionality in the production of uniform-quality whey-derived peptides.

Prediction of Apple Fruit Quality by Soil Nutrient Content and Artificial Neural Network

The effect of soil nutrient content on fruit yield and fruit quality is very important. To explore the effect of soil nutrients on apple quality we investigated 200 fruit samples from 40 orchards in Feng County, Jiangsu Province. Soil mineral elements and fruit quality were measured. The effect of soil nutrient content on fruit quality was analyzed by artificial neural network (ANN) model. The results showed that the prediction accuracy was highest (R2 = 0.851, 0.847, 0.885, 0.678 and 0.746) in mass per fruit (MPF), hardness (HB), soluble solids concentrations (SSC), titratable acid concentration (TA) and solid-acid ratio (SSC/TA), respectively. The sensitivity analysis of the prediction model showed that soil available P, K, Ca and Mg contents had the greatest impact on the quality of apple fruit. Response surface method (RSM) was performed to determine the optimum range of the available P, K, Ca, and Mg contents in orchards In Feng County, which were 10∼20 mg⋅kg−1, 170∼200 mg⋅kg−1, 1000∼1500 mg⋅kg−1, and 80∼200 mg⋅kg−1, respectively. The research also concluded that improving the content of available P and available Ca in orchard soil was crucial to improve apple fruit quality in Feng County, Jiangsu Province.

Recovery of Au and Cu from waste memory modules by electrolysis with hydrochloric acid-hydrogen peroxide system

E-waste is regarded as a special kind of solid waste, because its core components-waste memory modules (WMMs)-contain a large amount of high-value metal resources. However, there has been little research on the green recycling of key metals in WMMs. The difficulty lies in finding out how to reduce or eliminate the secondary pollution caused by the massive use of chemicals, and to improve the resource recovery rate. Therefore, this study constructed three systems based on an electrochemical method, to explore the leaching effects and principles of Au and Cu under different conditions (voltage, temperature, acid concentration and molar ratio). A response surface methodology called Box-Behnken Design was employed to optimize the parameters. The results showed that compared with other additives or without additives, H2O2 has the best effect on selective leaching of Au and Cu from WMMs. Meanwhile, HCl + H2O2 + direct current (DC) is the best system for selectively leaching Au and Cu compared to HCl + DC and HCl + H2O2. Appropriate increasing voltage, temperature and HCl concentration could effectively increase Au and Cu leaching rate, while the increase of mole ratio might inhibit Au and Cu leaching. The response surface quadratic model showed that the significance of Au response values was: voltage > n(HCl/H2O2) > temperature. Under the optimal conditions of 4.1 V DC constant voltage, 40 °C, 8.9 mol/L HCl concentration and 45 M ratio of acid to oxidant, the leaching rates of Au and Cu were 98.87 % and 92.10 %, respectively. It is worth noting that the electrolyte was composed of only HCl + H2O2, and electron was used as an oxidizing agent for potential controlling, which had the advantage of using less non-toxic and non-corrosive chemicals. The research results can provide a basis and technical support for e-waste recycling.