Isopropanol Concentration Research Articles

Selective adsorption of dyes on TiO2-modified hydroxyapatite photocatalysts morphologically controlled by solvothermal synthesis

Many industries use purification technologies to employ environmentally sustainable processes, and hydroxyapatite (HAp) is an excellent candidate as a catalyst support for the removal of organic pollutants. The adsorption and catalytic efficiency of HAp are considered to tune by changing the crystallographic properties of HAp. Needle-shaped HAp crystals were synthesized with TiO2 nanoparticles by solvothermal treatment using isopropanol at 150 °C. The concentration of isopropanol in the solvent ranged from 10% to 75%. The photocatalytic and adsorption properties of the samples were investigated using 5–100 ppm solutions of acidic acid fuchsin (AF) and basic methylene blue (MB) dyes. The aspect ratio of the HAp changed from 19.5 to 16.5 as the isopropanol concentration increased. In contrast to MB, the amount of AF adsorbed on the samples decreased as the aspect ratio increased, and the initial photocatalytic decolouration rate increased slightly. Although the zeta potential significantly decreased with the addition of TiO2, the change from 6.5 mV to −6.5 mV derived from the HAp aspect ratio clearly affected the adsorption of the dyes. These findings indicate the adsorption characteristics of HAp can be controlled by changing its aspect ratio, which will contribute to the design of HAp-based remediation materials.

Effect of 2-propanol content on solute retention mechanisms determined using amylose tris(3,5-dimethylphenylcarbamate) chiral stationary phase under normal- and reversed-phase conditions

The electrostatic interactions between chiral solutes and polysaccharide (PS)-based chiral selectors are the key to achieving chiral recognition; however, PS-based sorbents, derivatized of phenyl moieties, can exhibit considerably non-polar characteristics, and they are also useful for the separation of enantiomers in the reversed-phase mode. In this study, an immobilized amylose 3,5-dimethylphenylcarbamate-based sorbent was used to investigate the balance between electrostatic interactions and solvophobic interactions, with complementary effects on solute retention behavior when the isopropanol (IPA) concentration was altered. It was proposed that in both normal- and reversed-phase modes, information on the retention mechanisms could be obtained by observing the curvature of the logarithm of the retention factor versus the logarithm of the IPA concentration, and the slope values of the curves were related to the number of displaced IPA molecules upon solute adsorption. Using the proposed model and the two-site adsorption model, the retention behaviors of pantolactone (PL) enantiomers in both normal- and reversed-phase modes were investigated. The PL−sorbent interactions were classified into four types: electrostatic/enantioselective, electrostatic/nonselective, solvophobic/enantioselective, and solvophobic/nonselective. At IPA concentrations below 50 vol.% in n-hexane, the retention behaviors of PL were dominated by electrostatic/enantioselective sites, whereas at IPA concentrations beyond 50 vol.%, the solvophobic interactions of PL−sorbent were strengthened and mostly nonselective. By contrast, in the reversed-phase mode, a reverse in the enantiomeric elution order of PL was observed at 10 vol.% IPA, and considerably different enantioselectivity behaviors were found below and above 20 vol.%, indicating an abrupt change in the sorbent molecular environment. At IPA concentrations beyond 40 vol.%, the presence of PL-sorbent electrostatic interactions enhanced chiral recognition.

Clustering and Nonclustering Modifier Mixtures in Differential Mobility Spectrometry for Multidimensional Liquid Chromatography Ion Mobility-Mass Spectrometry Analysis.

Modifiers provide fast and reliable tuning of separation in differential mobility spectrometry (DMS). DMS selectivity for separating isomeric molecules depends on the clustering modifier concentration, which is typically 1.5-3 mol % ratio of isopropanol or ethanol in nitrogen. Low concentrations (0.1%) of isopropanol were found to improve resolution and sensitivity but at the cost of practicality and robustness. Replacing the single-channel DMS pump with a binary high-performance liquid chromatography (HPLC) pump enabled the generation of modifier mixtures at a constant flow rate using an isocratic or gradient mode, and the analytical benefits of the system were investigated considering cyclohexane, n-hexane, or n-octane as nonclustering modifiers and isopropanol or ethanol as clustering modifiers. It was found that clustering and nonclustering modifier mixtures enable optimization of selectivity, resolution, and sensitivity for different positional isomers and diastereoisomers. Data further suggested different ion separation mechanisms depending on the modifier ratios. For 85 analytes, the absolute difference in compensation voltages (CoVs) between pure nitrogen and cyclohexane at 1.5 mol % ratio was below 4 V, demonstrating its potential as a nonclustering modifier. Cyclohexane's nonclustering behavior was further supported by molecular modeling using density functional theory (DFT) and calculated cluster binding energies, showing positive ΔG values. The ability to control analyte CoVs by adjusting modifier concentrations in isocratic and gradient modes is beneficial for optimizing multidimensional LCxDMS-MS. It is fast and effective for manipulating the DMS scanning window size to realize shorter mass spectrometry (MS) acquisition cycle times while maintaining a sufficient number of CoV steps and without compromising DMS separation performance.

Effect of Isopropyl Alcohol Concentration on the Size and Number of Droplets after Coal-Water Fuel Spraying

AbstractCoal-water slurries are promising fuels for thermal power engineering. One of the main problems with their combustion is formation of fairly large (with characteristic sizes of more than 1 ...

High performance isopropanol sensor based on spinel ZnMn2O4 nanoparticles

Spinel-type ZnMn2O4 nanoparticles with sizes between 40 and 90 nm were synthesized successfully via an ultrasound-assisted colloidal method using dodecylamine as a surfactant agent. The formation of spinel ZnMn2O4 was identified from structural and morphological characterizations using X-ray diffraction, Raman spectroscopy, electron microscopy, energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. The ZnMn2O4 sensor exhibited good gas sensing performance to isopropanol vapor at an operating temperature of 250 °C. The sensor was able to detect concentrations of isopropanol in the range of 10–100 ppm, having a gas response from 22 to 99 %, respectively. A theoretical detection limit of 666 ppb with a gas response of ∼5.2 % was estimated. The ZnMn2O4 sensor also showed a reproducible, repeatable, and stable electrical signal. The outstanding gas sensing performance revealed that the ZnMn2O4 can be used as a new sensing material for isopropanol vapor.

Hydrogen bonding and percolation in propan-2-ol – Water liquid mixtures: X-ray diffraction experiments and computer simulations

Synchrotron X-ray diffraction measurements have been conducted on aqueous mixtures of propan-2-ol (a.k.a. isopropanol, or 2-propanol), for alcohol contents between 10 and 90 mol%, from room temperature down to 230 K. Molecular dynamics simulations, by using an all-atom parametrization of the propan-2-ol molecule and the well-known TIP4P/2005 water model, were able to provide semi-quantitative descriptions of the measured total structure factors. Various quantities related to hydrogen bonding, like hydrogen bond numbers, size distribution of cyclic entities and cluster size distributions, have been determined from the particle co-ordinates obtained from the simulations. The percolation threshold at room temperature could be estimated to be between isopropanol concentrations of 62 and 74 mol%, whereas at very low temperature, calculations yielded a value above 90 mol%.

Fabrication and study of Raman signal enhancement of pyramid/nano-Ag structured Silic substrate

The pyramid-structured silicon substrate was successfully fabricated by a chemical corrosion method with an average thickness of about 1 - 3 μm with the optimal parameters such as corrosion temperature of 70oC, corrosion time of 5 min, concentration KOH of 3 M and isopropyl alcohol concentration of 1 M. After that, the silver nanoparticles layer (thickness 20 nm) was coated on the silicon substrate by a sputtering method to enhance the SERS signal. The results proved that the Pyramid/nano Ag structure silicon substrate showed the enhancement effect of Raman signal, and Rhodamine 6G pigment in food at low concentration (10-6 M) was detected and the enhancement factor was 9.7 × 102.

Tuned Transport Behavior of the IPA-Treated PEDOT:PSS Flexible Temperature Sensor via Screen Printing

A flexible temperature sensor based on poly-(3, 4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) with isopropyl alcohol (IPA) treatment is successfully fabricated by screen printing. The distribution of PEDOT is investigated by the SEM, AFM, and Raman techniques. It can be found that the microstructure is manipulated by the ratio of the PEDOT:PSS to IPA content. Raman spectra demonstrate that the transition between quinoid and benzoid structures of PEDOT are tuned by IPA treatment as well. The temperature dependence of resistance for IPA-treated PEDOT:PSS film is found to be well fitted by non-adiabatic small polaron hopping transport. Moreover, a constant temperature coefficient of resistance (TCR) value can be obtained by the optimized ratio of IPA to PEDOT:PSS. Therefore, this paper suggests that the tuned microstructure of PEDOT:PSS film can be realized by IPA treatment, which plays an important role in the physical properties of the temperature sensor based on PEDOT:PSS.

Mechanism of Gold-Silver Alloy Nanoparticle Formation by Laser Coreduction of Gold and Silver Ions in Solution.

Photochemical reduction of aqueous Ag+ and [AuCl4]- into alloy Au-Ag nanoparticles (Au-Ag NPs) with intense laser pulses is a green synthesis approach that requires no toxic chemical reducing agents or stabilizers; however size control without capping agents still remains a challenge. Hydrated electrons produced in the laser plasma can reduce both [AuCl4]- and Ag+ to form NPs, but hydroxyl radicals (OH·) in the plasma inhibit Ag NP formation by promoting the back-oxidation of Ag0 into Ag+. In this work, femtosecond laser reduction is used to synthesize Au-Ag NPs with controlled compositions by adding the OH· scavenger isopropyl alcohol (IPA) to precursor solutions containing KAuCl4 and AgClO4. With sufficient IPA concentration, varying the precursor ratio enabled control over the Au-Ag NP composition and produced alloy NPs with average sizes less than 10 nm and homogeneous molar compositions of Au and Ag. By investigating the kinetics of Ag+ and [AuCl4]- coreduction, we find that the reduction of [AuCl4]- into Au-Ag NPs occurs before most of the Ag+ is incorporated, giving us insight into the mechanism of Au-Ag NP formation.

Concentrations of volatile substances in costal cartilage in relation to blood and urine - preliminary studies.

The study aimed to examine whether volatile substances (ethanol, isopropanol, and acetone) can be detected in costal cartilage and also if concentrations of detected substances reliably reflect their concentrations in the peripheral blood - the standard forensic material for toxicological analyses. Such knowledge can be useful in cases when a cadaver's blood is unavailable or contaminated. Ethanol, isopropanol, and acetone concentrations were determined in samples of unground costal cartilage (UCC), ground costal cartilage (GCC), femoral venous blood, and urine. The samples were analysed by gas chromatography (GC) with a flame ionization detector using headspace analysis. Volatile substances were detected in 12 out of 100 analysed samples. There was a strong positive correlation between ethanol concentration in the blood and urine (r = 0.899, p < 0.001), UCC (r = 0.809, p < 0.01), and GCC (r = 0.749, p < 0.01). A similar strong correlation was found for isopropanol concentration in the blood and urine (r = 0.979, p < 0.001), UCC (r = 0.866, p < 0.001), and GCC (r = 0.942, p < 0.001). Acetone concentration in the blood strongly correlated only with its concentration in urine (r = 0.960, p < 0.001). We demonstrated for the first time the possibility of detecting volatile substances: ethanol, isopropanol and acetone in a human costal cartilage. Also, the study showed that higher volatiles concentrations were better determined in ground samples.

Dynamic Simulation, Parameter Optimization, and Control of a Reactive Distillation Column for Production of Isopropanol via Propylene Hydration

In this study, a reactive distillation column for production of isopropanol was investigated. Firstly, a dynamic model was developed for the process. The model of the process was then programmed, and the process simulated using a base case obtained from the literature. Results showed that distillate contained more than 58 mol% propylene-free&lt;br /&gt; isopropanol. In the next step, optimization of some operating variables was performed to&lt;br /&gt; maximize concentration of isopropanol in distillate with condenser temperature as constraint, which was considered to be above the freezing point of water. Several simulations were performed by changing operating parameters, and finally optimum isopropanol content in distillate was obtained above 58 mol%. Results of using classic controllers showed that PID controller had the best performance for both condenser temperature set-point tracking and disturbance rejection.

Optimal pH for indirect electrochemical oxidation of isopropyl alcohol with Ru-Ti anode and NaCl electrolyte

When the levels of human waste exceed an ecosystem’s native purification capacity, pollution causes large, long-term damage. Therefore, to prevent wastewater spillage from damaging the environment and raising external cost to the society, industries are required to degrade pollutants in wastewater to an acceptable level according to local regulations before emission. This investigation uses an electrochemical system to degrade isopropanol—a common pollutant found in wastewater—and find the optimal pH level at which the highest degradation of isopropanol takes place. We hypothesized that by decreasing the pH value due to an increase in the amount of HClO (a strong oxidant) in the solution, the degradation of isopropanol (IPA) into acetone should increase. The result supports the hypothesis and shows the electrochemical system under acidic conditions has a higher efficiency than alkaline conditions. Under pH 5–6, NaCl concentration of 2%, initial IPA concentration of 500 ppm total organic carbon, and a current of 1 ampere, the electrochemical system degrades 98.6% of IPA into acetone and other intermediate compounds in under 180 minutes. Furthermore, with such a high transfer rate, the system demonstrates its potential to degrade isopropanol to generate acetone, which is a commonly-used agent found in a variety of products ranging from lab cleaning products to nail varnish.

Determining the influence of cavitation treatment on the octane number of gas-condensate gasoline modified with isopropanol

This paper reports a study into the effect of cavitation on the octane number of gas-condensate gasoline with the addition of isopropanol in the amount of 0‒12 % by volume. The papers that confirm the impact of cavitation on the intensification of oil cracking reactions have been analyzed. Cavitation also initiates reactions of interaction between free radicals and alcohols. A laboratory installation scheme has been proposed to investigate the cavitation treatment process on the characteristics of gasoline modified with alcohols. A methodology has been devised for studying the effect of cavitation treatment intensity on the octane number of gasoline. A 0.3‒0.9-point increase in the octane number of gas-condensate gasoline modified with isopropanol was experimentally proven following its cavitation treatment. The effect of the number of cavitation treatment cycles on the octane number indicator has been studied; it is shown that the stable value of an increase in the octane number is achieved over 7‒8 cycles of cavitation treatment at a pressure at the outlet from the nozzle of 9.0 MPa. A reduction in the isopropanol additive, required to produce gasoline brands A-95 and A-98, when using a cavitation treatment technology was substantiated. It has been experimentally confirmed that compared to simple mechanical mixing of alcohol and hydrocarbon gasoline, the application of cavitation reduces the consumption of isopropanol by 17 % (from 3.0 % to 2.5 % by volume) in the production of gasoline brand A-95; and by 14 % (from 8.1 % to 7.0 % % by volume) in the production of gasoline brand A-98. The effect of isopropanol concentration on the increase in the octane number of gasoline, measured by research method, under conditions of cavitation treatment is nonlinear in nature: with highs at concentrations of 1.0 % by volume, 3.5 % by volume, and 6.5 % by volume. Varying the initial concentration of isopropanol and the octane number of a hydrocarbon gasoline fraction can optimize the technological mode of production of gasoline brands A-95 and A-98 in terms of raw materials and energy consumption

Dual-target gas-phase biosensor (bio-sniffer) for assessment of lipid metabolism from breath acetone and isopropanol

Volatile organic compounds (VOCs) in breath and skin gas are promising samples for non-invasive and simple disease screening and metabolism assessment. In addition, simultaneous measurement of multiple VOCs helps to improve the examination quality and allows for more reliable disease screening and investigation of detailed metabolic pathways. In this study, we have developed a dual-target gas-phase biosensor (bio-sniffer) that allows for measurement of isopropanol (IPA) and acetone vapours, relevant VOCs for lipid metabolisms, by simply exchanging coenzyme solutions. The measurement exploited a reversible redox reaction that was catalysed by secondary alcohol dehydrogenase (S-ADH). IPA/acetone was oxidised/reduced together with reduction/oxidation of a coenzyme, oxidised (NAD+)/reduced (NADH) form of β-nicotinamide adenine dinucleotide, depending on surrounding pH (8.5/7.5). This reaction resulted in producing/consuming NADH which exhibited autofluorescence (λex = 340 nm, λfl = 490 nm), by which IPA/acetone was measured. The characterization of the dual-target bio-sniffer showed the dynamic ranges for IPA and acetone vapour were 3.3–1000 ppb and 13.0–3000 ppb, respectively, which encompasses those in the breath of healthy people (IPA, 10–30 ppb; acetone, 200–900 ppb). Finally, the dual-target bio-sniffer was applied for measurement of IPA and acetone in the breath of healthy people. As with the standard IPA and acetone vapour, intermittent and repeated measurement of both VOCs in the breath was demonstrated. These results indicated that the dual-target bio-sniffer would be a useful tool to assess the lipid metabolism in detail by measuring temporal changes of IPA and acetone concentrations in the breath.

Ultra-Sensitive Isopropanol Biochemical Gas Sensor (Bio-Sniffer) for Monitoring of Human Volatiles.

Our groups have previously developed a biochemical gas sensor to measure isopropanol (IPA) in exhaled air and have applied it for breath IPA investigation in healthy subjects and diabetes patients. In this study, the original bio-sniffer was modified with a series of components that improved the limit of detection (LOD). First, the modified IPA bio-sniffer used a C8855-type photomultiplier tube (PMT) that performed well in the photon sensitivity at the peak wavelength of nicotinamide adenine dinucleotide (NADH) fluorescence. Second, the multi-core bifurcated optical fiber, which incorporated 36 fibers to replace the previous dual-core type, enhanced the fluorescence collection. Third, the optical fiber probe was reinforced for greater width, and the flow-cell was redesigned to increase the area of the enzyme-immobilized membrane in contact with the air sample. These modifications lowered the detection limit to 0.5 ppb, a significant increase over the previous 1.0 ppb. Moreover, the modified bio-sniffer successfully analyzed the IPA concentration in exhaled air from a volunteer, which confirmed its capability for real-world sample detection. The modified bio-sniffer is more applicable to breath measurement and the detection of other extremely-low-concentration samples.

Gas-phase isopropanol degradation by nonthermal plasma combined with Mn-Cu/-Al2O3.

In this study, the dielectric barrier discharge (DBD) induced by nonthermal plasma (NTP) technology was used for isopropanol (IPA) degradation. IPA, intermediate, final product, and ozone concentrations were analyzed using GC-MS, carbon dioxide detector, and ozone detector. The experimental flow rate and concentration were fixed to 1 L/min and 1200 ppm ± 10%, respectively. Different reaction procedures were proposed for self-made metal catalyst combined with a plasma system (plasma alone and γ-Al2O3 combined with plasma, Cu (5 wt%)/γ-Al2O3 combined with plasma, Mn (3 wt%)-Cu (5 wt%)/γ-Al2O3 combined with plasma). In addition, the effect of the carrier gas oxygen content (0%, 20%, and 100%) on IPA conversion and intermediate and carbon dioxide selectivity was also investigated. The results revealed that the Mn (F)-Cu/γ-Al2O3 combined with plasma exhibited more efficient IPA conversion. In the 100% oxygen environment, the IPA conversion rate increased from 79.32 to 99.99%, and carbon dioxide selectivity increased from 3.82 to 50.23%. IPA was completely converted after 60 min of plasma treatment with the acetone selectivity, carbon dioxide selectivity, and tail ozone concentration of 26.71% ± 1.27%, 50.23% ± 0.56%, and 1761 ± 11 ppm, respectively. This study proved that the current single planar DBD configuration is an effective advanced treatment technology for the decomposition of VOCs.

Study of conductivity, contact angle and surface free energy of anionic (SDS, AOT) and cationic (CTAB) surfactants in water and isopropanol mixture

The thermodynamic properties of cationic surfactant CTAB (cetyltrimethylammonium bromide), anionic surfactant SDS (sodium dodecyl sulfate), and AOT (Aerosol OT) in pure water and 0.1, 0.2, 0.3, and 0.4 volume fraction of isopropanol were observed by measuring the conductivity at 298.15 K. Various physicochemical properties like CMC, α and the thermodynamic properties like standard free energy of micellization (∆Gmo), the free energy of surfactant tail transfer (∆Gtranso) were calculated. Also, (log S1 and log S2), α, CMC, K0KCMC, ∆Gmo and ∆Gtranso are correlated with the volume fraction of isopropanol. The result revealed a sharp increase in conductivity with an increase in surfactant concentration. With the increasing isopropanol content in the solvent composition, the critical micelle concentration (CMC) of the CTAB and SDS increased. The degree of micellar dissociation (α) as well as the Gibbs' free energy was found to be increased with the increasing volume fraction of isopropanol. The correlation of ∆Gmo with the solvent parameters and the solvophobic parameter were also included. The contact angle and surface free energies over the aluminum foil surface were also evaluated using a drop shape analyzer (DSA-25E).

Ignition of coal‐water fuel droplets with addition of isopropyl alcohol

Coal-water fuels have been actively studied in the last decade due to the fact that when they are burned in the furnaces of steam and hot-water boilers, much less anthropogenic oxides of sulfur, nitrogen, and carbon are formed in comparison with coal. The main problem that hinders the widespread introduction of such fuels in the energy sector is long (up to 30 seconds) ignition delay times. Significant (10%-50%) reduction in the ignition delay time is possible when a small (up to 10%) amount of available and inexpensive liquid combustible organic compounds are added to the suspension. The purpose of the work is to substantiate (from the results of experimental studies) the possibility of significant reduction of the ignition delay times of coal-water fuels by introducing a third component into the suspension—isopropyl alcohol in relatively small (from 3% to 8%) concentrations. According to the results of experimental studies on the ignition process of multicomponent coal-water fuel droplets, based on long-flame coal, with addition of isopropyl alcohol in oxidizer (still air) heated to high temperatures (from 873 to 1273 K), with recording the processes of heating, ignition, and combustion by a high-speed video camera (speed of shooting up to 105 frames per second), the mechanism, characteristics, and conditions of ignition of the researched compositions of quite promising fuels were established. Experiments have shown that the delay time of stable ignition of the studied suspensions based on long-flame coal decreases by 12% to 47% with the increase (from 3% to 8%) of the mass concentration of isopropyl alcohol in the composition of coal-water fuel at the initial characteristic size of droplets from 1.5 to 3.5 mm. Each studied composition was compared with conventional coal-water fuel burned under similar conditions. The influence of mass concentration of isopropyl alcohol in the composition of the coal-water fuel on the characteristics of the initiation of ignition and combustion processes, established in the experiments, proves the possibility of effective an application of such three-component suspensions in thermal power engineering. The possibility of formation of a significantly larger quantity (about 80%) of small droplets (250-400 μm) in the flow during atomization of coal-water fuel with addition of isopropyl alcohol in comparison with the usual coal-water suspension was experimentally proved. The results are of significant practical importance because they illustrate the possibility of achieving optimum conditions for ignition and combustion of promising multi-component coal-water slurries with the addition of alcohol in the furnaces of boiler plants of large- and small-scale power engineering.

Effect of solvent absorption on the optical properties of 3D printed methacrylate waveguide

Methacrylate-based photopolymer waveguides are 3D printed using stereolithography as a single-step fabrication technique and the light propagation through these waveguides is investigated in the presence of various solvents. Solvent absorption on the photopolymer surface is found to play a significant role in the optical output power of the waveguide. Swelling of the photopolymer caused by the solvent absorption is found to increase the optical power transmission through the waveguide. Mixing isopropanol and glycerol with DI water separately at specific concentrations so that their respective refractive indices remain similar, it is observed that isopropanol samples increase the optical power by ~36% compared to glycerol samples, which showed optical power enhancement around 4.9%. A first-order optical model is presented that shows the increase in optical power has a spontaneous response due to the change in the refractive index of the waveguide surface upon solvent contact, followed by a dynamic response due to the formation of the swelling layer as the absorbed solvent diffuse inside the polymer. The methacrylate-based waveguide also showed selectivity towards different concentrations of isopropanol. Results from our study show that the optical properties of the given methacrylate-based photopolymer are largely affected by the absorption affinity of the solvent towards the photopolymer rather than the solvent’s refractive index, which can be crucial for designing integrated optical devices using methacrylate-based photopolymers that work in a different solvent condition.

Primary Purification of Plasmid DNA Using Differential Isopropanol Precipitation.

A method for the intermediate recovery of plasmid DNA (pDNA) from alkaline lysates is described that comprises differential isopropanol precipitation steps. In a first low-cut precipitation, a smaller amount of isopropanol (20% v/v) is used so that only high molecular weight RNA precipitates. After solid liquid separation, a high-cut precipitation is performed by bringing isopropanol concentration to 70% v/v to precipitate pDNA. Tests made with lysates show that the differential precipitation increases purity threefold compared to the conventional one-step precipitation at 70% v/v without affecting pDNA recovery (>80%).