Traditional Solvent Extraction Method Research Articles

An in-situ versatile screening method for identifying SVOC sources in indoor environments

Indoor semivolatile organic compounds (SVOCs) pose a substantial threat to human health. However, identifying the sources of these emissions has been challenging owing to the scarcity of convenient and practical on-site methodologies. Herein, a novel method for source screening was proposed using aluminum silicate sampling strips to adsorb SVOCs from the surface air of indoor materials. The adsorbed SVOC levels indicate the emission intensity of these materials into indoor environments. Additionally, compact sampling strips can be readily fixed to any vertical surface using a static sticker, facilitating the characterization of various materials in practical settings. Laboratory-simulated experiments demonstrated the capability of the proposed method to differentiate between source and non-source materials within a 10-cm distance in the same space. In practical scenarios, the primary emission sources identified via this method exhibited a consistent correlation with the contents of the corresponding materials obtained from the traditional solvent-extraction method. As the adsorbed SVOCs were directly transferred to a GC–MS through thermal desorption instead of the solvent-extraction procedure, the proposed method demonstrated several-fold improvements in analytical sensitivity and efficiency. Using this versatile screening technique, some emerging and important SVOC species were identified within specific indoor materials. Eliminating these sources has been demonstrated as an effective approach to mitigate SVOC pollution. Overall, the proposed method offers a powerful tool for managing indoor pollutants and safeguarding human health.

Direct Extraction and Determination of Free Nicotine in Cigarette Smoke.

The accurate determination of the free nicotine content in cigarette smoke is crucial for assessing cigarette quality, studying harm and addiction, and reducing tar levels. Currently, the determination of free nicotine in tobacco products primarily relies on methods such as pH calculation, nuclear magnetic resonance (NMR) spectroscopy, headspace solid-phase microextraction (HS-SPME), and traditional solvent extraction. However, these methods have limitations that restrict their widespread application. In this study, the free nicotine in cigarette smoke was directly extracted by using cyclohexane according to the traditional solvent extraction method and detected via gas chromatography-mass spectrometry. Compared with the traditional two-phase solvent extraction, our experimental method is easy to execute and eliminates the influence of aqueous solutions on the original distribution of nicotine in cigarette smoke particulate matter. Furthermore, the presence of protonated nicotine in tobacco does not affect the determination. Compared with HS-SPME and NMR spectroscopy, our approach, which involves solvent extraction followed by chromatographic separation and instrumental detection, offers simplicity, improved precision, better detection limits, and reduced interference during the instrumental detection stage. The standard addition recoveries in the conducted experiment ranged from 96.2% to 102.5%. The limit of detection was 2.8 μg/cig, and the correlation coefficient (R2) for the quadratic regression of the standard curve exceeded 0.999. The relative standard deviation for parallel samples was between 1.7% and 3.4% (n = 5), fully meeting the requirements for the determination of free nicotine in cigarette smoke. Analysis of cigarette samples from 38 commercially available brands revealed that the content of free nicotine ranged from 0.376 to 0.716 mg/cig, with an average of 0.540 mg/cig, and free nicotine accounted for 39.1%-88.8% of the total nicotine content.

Natural deep eutectic solvents: promising agents for extracting substances from plant materials

There is a growing trend to replace synthetic products or additives with natural alternatives. Historical experience and developments in human health science demonstrate the adverse effects of xenobiotics on human health and metabolism. The shift toward natural products is essential for enhancing vitality, social activity, and overall quality of life, while preventing adverse events and diseases. Industries such as pharmaceutical, cosmetic, and food are increasingly turning to natural and biologically active chemicals isolated from plants or microorganisms. However, the primary challenge lies in developing effective and eco-friendly methods for their isolation. Deep eutectic solvents are a mixture of two or more components with unique properties like low volatility, low melting points, ease of preparation, cost-effective starting materials, and minimal toxicity to humans. They have gained popularity as environmentally friendly agents for extracting biologically active substances from medicinal plants and as safe alternatives for various industries, including food and pharmaceuticals. Traditional organic solvent extraction methods have several drawbacks, including long extraction times, safety concerns, environmental damage, high cost, and the need for large solvent volumes. This review summarizes research progress on the benefits of using deep eutectic solvents for extracting bioactive compounds, including phenolic acid, flavonoids, isoflavones, catechins, polysaccharides, curcuminoids, proanthocyanidin, phycocyanin, gingerols, ginsenosides, anthocyanins, rutin, and chlorogenic acids. Additionally, it examines the biological activity of these extracts, including antioxidant, antibacterial, and antitumor properties.

Multiple Rounds of In Vivo Random Mutagenesis and Selection in Vibrio natriegens Result in Substantial Increases in REE Binding Capacity.

Rare earth elements (REE) are essential ingredients in many modern technologies, yet their purification remains either environmentally harmful or economically unviable. Adsorption, or biosorption, of REE onto bacterial cell membranes offers a sustainable alternative to traditional solvent extraction methods. But in order for biosorption-based REE purification to compete economically, the capacity and specificity of biosorption sites must be enhanced. Although there have been some recent advances in characterizing the genetics of REE-biosorption, the variety and complexity of bacterial membrane surface sites make targeted genetic engineering difficult. Here, we propose using multiple rounds of in vivo random mutagenesis induced by the MP6 plasmid combined with plate-throughput REE-biosorption screening to improve a microbe's capacity and selectivity for biosorbing REE. We engineered a strain of Vibrio natriegens capable of biosorbing 210% more dysprosium compared to the wild-type and produced selectivity improvements of up to 50% between the lightest (lanthanum) and heaviest (lutetium) REE. We believe that mutations we observed in ABC transporters as well as a nonessential protein in the BAM outer membrane β-barrel protein insertion complex likely contribute to some─but almost certainly not all─of the biosorption changes we observed. Given the ease of finding significant biosorption mutants, these results highlight just how many genes likely contribute to biosorption as well as the power of random mutagenesis in identifying genes of interest and optimizing a biological system for a task.

Influence of solvent-free extraction of fish oil from catfish (Clarias magur) heads using a Taguchi orthogonal array design: A qualitative and quantitative approach.

This study aimed to efficiently utilize catfish heads, enhancing the oil extraction process while improving the cost-effectiveness of fish byproduct management. The study employed the wet rendering method, a solvent-free approach, utilizing a two-factor Taguchi orthogonal array design to identify critical parameters for optimizing oil yield and ensuring high-quality oil attributes. The extraction temperature (80-120°C) and time (5-25 min) were chosen as variables in the wet rendering process. Range analysis identified the extraction time as a more significant (p < 0.05) factor for most parameters, including oil yield, oil recovery, acid value, free fatty acids, peroxide value, and thiobarbituric acid reactive substances. The extraction temperature was more significant (p < 0.05) for oil color. Consequently, the wet rendering method was optimized, resulting in an extraction temperature of 80°C and an extraction time of 25 min, yielding the highest oil yield. This optimized wet rendering process recovered 6.37 g/100 g of oil with an impressive 54.16% oil recovery rate, demonstrating comparable performance to traditional solvent extraction methods. Moreover, Fourier transfer infrared spectra analysis revealed distinct peaks associated with triacylglycerols and polyunsaturated fatty acids (PUFA). The oil recovered under optimized conditions contained higher levels of PUFA, including oleic acid (189.92 μg/g of oil), linoleic acid (169.92 μg/g of oil), eicosapentaenoic acid (17.41 μg/g of oil), and docosahexaenoic acid (20.82 μg/g of oil). Volatile compound analysis revealed lower levels of secondary oxidation compounds under optimized conditions. This optimized wet rendering method offers practical advantages in terms of cost-efficiency, sustainability, reduced environmental impact, and enhanced oil quality, making it an attractive option for the fish processing industries. Future research possibilities may include the purification of the catfish head oil and its application in the food and pharmaceutical industries.

A novel hydrangea-like magnetic composite Fe3O4@MnO2@ZIF-67 for efficient selective adsorption of Pd(II) from metallurgical wastewater

The selective adsorption of palladium from wastewater is a feasible solution to solving palladium pollution and resource scarcity. Because traditional solvent extraction methods often involve the use of considerable amounts of organic solvents, research is focused on investigating adsorption techniques that can selectively remove palladium from wastewater. In this paper, the magnetic composite Fe3O4@MnO2@ZIF-67 was synthesized and its performance for the adsorption of Pd(II) in acidic water was investigated. Fe3O4@MnO2@ZIF-67 was characterized by various analytical methods such as TEM, SEM, EDS, BET, XRD, FTIR, zeta potential analysis, VSM, and TGA. The effects of palladium ion concentration, contact time, pH, and temperature on adsorption were evaluated. The kinetics were shown to follow the pseudo-second-order kinetic model and Elovich model, and the rate-limiting step was chemisorption. Thermodynamic studies showed that increasing the temperature promoted the adsorption of Pd(II), and the maximum uptake capacity of Fe3O4@MnO2@ZIF-67 for Pd(II) was 531.91 mg g−1. Interestingly, Fe3O4@MnO2@ZIF-67 exhibited superior selectivity for Pd(II) in the presence of Ir(IV), Pt(IV), and Rh(III). The adsorbent can be used repeatedly for selective adsorption of palladium. Even at the fifth cycle, the uptake rate of Pd(II) remained as high as 83.1%, and it showed a favorable adsorption capacity and selectivity for Pd(II) in real metallurgical wastewater. The adsorption mechanism was analyzed by SEM, FTIR, XRD, XPS, and DFT calculations, which indicated that electrostatic interactions and coordination with nitrogen-containing groups were involved. Fe3O4@MnO2@ZIF-67 is a promising adsorbent for the efficient adsorption and selective separation of palladium ions.

Thermal desorption-based method for quantifying semi-volatile organic compounds in house dust: Method development and evaluation

As an important storage medium of semi-volatile organic compounds (SVOC) in indoor environments, house dust has been extensively used to assess the pollution level of indoor SVOC. SVOC in house dust are commonly quantified using solvent-extraction methods, which are however solvent-consuming, time-consuming and laborious. Thermal desorption (TD, solvent-free and easy-to-use) is a good alternative to solvent extractions, but its performance for analyzing house dust is still unverified. Therefore, we proposed a TD-based method for quantifying SVOC in house dust by incorporating the TD technique with GC-MS. Laboratory experiments (48 samples with high SVOC concentrations) and field-test experiments (12 samples with low SVOC concentrations) were performed to justify the proposed method by comparing its results to those of a traditional solvent-extraction method (Soxhlet extraction). For laboratory dusts, the accuracy (relative deviation &lt; 20%) and repeatability (relative standard deviation &lt; 13%) of the TD-based method were comparable to the solvent-extraction method. For field-test dusts, higher SVOC concentrations were typically obtained by the TD-based method, implying its superior performance. These results gave evident confidence in the performance of the TD-based method, which facilitated the simple, solvent-free and accurate quantification of SVOC in house dust.

Microwave-ultrasonic technique development coupled with natural deep eutectic solvents in anthocyanin extraction from perilla leaves (Perilla frutescens var. Acuta).

As potent antioxidants, anthocyanins can protect the body from free radicals. However, the traditional solvent extraction method has the disadvantages of requiring a high extraction temperature and long extraction time, so it is necessary to develop an efficient extraction method for anthocyanins. In this study, the technique of natural deep eutectic solvents (DESs) was applied to extract anthocyanins from purple perilla leaves with the aid of microwave-ultrasonic assisted extraction (MUAE). The response surface methodology (RSM), based on the Box-Behnken design (BBD), predicted the maximum extraction yield of anthocyanins to be 619.62 mg (100 g)-1 under the following conditions: x1 (ultrasonic extraction power)=357.25 W, x2 (time)=25.62 min, and x3 (temperature)=57.80 °C. The biological activity of the extract obtained was evaluated by examining its radical-scavenging effect on 1,1-diphenyl-2-picrylhydrazyl, hydroxyl radical, and superoxide anion radicals. Its bacteriostatic impact was investigated on four typical bacteria: Shewanella putrefaciens (S. putrefaciens), Pseudomonas fluorescens (P. fluorescens), Escherichia coli (E. coli), and Staphylococcus aureus (S. aureus). The integrated extraction method of DESs with MUAE was efficient, energy-saving, green, and sustainable. © 2022 Society of Chemical Industry.

Improving the Photovoltaic Performance of Dithienobenzodithiophene-Based Polymers via Addition of an Additional Eluent in the Soxhlet Extraction Process.

Dithieno[2,3-d;2',3'-d']benzo[1,2-b;4,5-b']dithiophene (DTBDT) is a kind of pentacyclic aromatic electron-donating unit with unique optoelectronic properties, but it has received less attention in the design of photovoltaic polymers. In this work, we copolymerized DTBDT with the electron-deficient unit of dithieno[3',2':3,4;2″,3″:5,6]benzo[1,2-c][1,2,5]thiadiazole (DTBT) and obtained two polymers, PE55 and PE56, with a synergistic heteroatom substitution strategy. When blended with the classic nonfullerene acceptor Y6, PE55 and PE56 achieve power conversion efficiencies (PCEs) of 13.78% and 14.49%, respectively, which indicates that the introduction of sulfur atoms on the conjugated side chain of the D unit is a promising method to enhance the performance of DTBDT-based polymers. Besides, we utilize dichloromethane and chloroform to separate the low molecular weight (Mw) fractions in the solvent extraction process to obtain PE55-CF and PE56-CB, and the PCEs are further improved to 15.00% and 16.11%, respectively. The stronger π-π stacking, optimized blend film morphology, and higher charge mobilities contribute to the enhanced PCEs for polymers with higher Mw obtained via the multistep solvent extraction strategy. Our results not only provide a simple and effective way to improve the photovoltaic performance of conjugated polymers but also imply that some reported polymers purified from the traditional one-step solvent extraction method might be seriously underestimated.

Anti-aging and Antioxidant Activities of Ethanol and Three-phase Partitioned Extracts of Inula viscosa

Inula viscosa is a plant commonly used to treat inflammation, germicide, expectorant, cough reducer, diuretic, anemia, and cancer. In addition to its medicinal effect, this plant has been preferred because it is thought to be a free radical scavenger and anti-aging effect due to its phenolic compounds. The aim of the study was to determine whether the plant has antioxidant and anti-aging potential. The plant was extracted with both the traditional solvent extraction method with ethanol and the novel three-phase partitioned (TPP) system, and the two methods were compared. The methods of DPPH free radical scavenging, ABTS cation radical scavenging, superoxide anion radical scavenging, and reduction of copper and iron ions were used to determine the antioxidant effects of the obtained extracts. In addition, elastase enzyme inhibition was studied to investigate the anti-aging potential. TPP method (23.9% yield) was performed at a higher yield than the solvent extraction (8.99% yield). The ethanolic extract and TPP extract of plant inhibited the DPPH free radical with IC50=0.27 µg/mL and IC50=0.026 µg/mL, and ABTS cation radical with IC50=0.28 µg/mL and IC50=0.13 µg/mL, and superoxide anion radical with IC50=3.53 µg/mL and IC50=2.43 µg/mL, respectively. According to the elastase inhibition results, IC50=3.11 µg/mL for ethanol extract and IC50=3.05 µg/mL for TPP extract were obtained. Both extracts of I. viscosa showed antioxidant and anti-aging effects at levels close to the standards. In addition, according to the results, TPP extract was found to be more effective than ethanol extract.

Layered Double Hydroxide@Metal-Organic Framework Hybrids for Extraction of Indole-3-Carbinol From Cruciferous Vegetables.

Cruciferous vegetables are rich in glucosinolates, which can be metabolized to produce the antitumor compound indole-3-carbinol (I3C). The conventional solvent extraction method for I3C is inefficient. To improve the extraction efficiency of I3C from cruciferous vegetables, we prepared a metal-organic framework (MOF) material (Fe3O4@Zn-Al-LDH@B-D-MIL-100). First, Fe3O4 nanoparticles were introduced to layered double hydroxides by in situ polymerization. Then, the MOF material was grown on the surface of the layered double hydroxide by co-precipitation and the layer-by-layer self-assembly method. This gave Fe3O4@Zn-Al-LDH@B-D-MIL-100, which was characterized using a variety of techniques. The results showed that Fe3O4@Zn-Al-LDH@B-D-MIL-100 had a double-layer porous structure, excellent superparamagnetism (11.54955 emu/g), a large specific surface area (174.04 m2/g), and a pore volume (0.26 cm3/g). The extraction conditions for I3C were optimized. Non-linear fitting of the static adsorption model showed that the adsorption was mainly monolayer. Fe3O4@Zn-Al-LDH@B-D-MIL-100 had fast adsorption kinetics and could extract 95% of I3C in 45 min. It is superior to the traditional solvent extraction method because of its high enrichment efficiency in a short time and environmental friendliness. The successful preparation of the new nanomaterial will provide a new reference for the enrichment and extraction of the I3C industry.

Lipid extraction from microalgae using pure caprolactam-based ionic liquids and with organic co-solvent

Background The main process limitation of microalgae biofuel technology is lack of cost-effective and efficient lipid extraction methods. Thus, the aim of this study was to investigate the effectiveness and efficiency of six caprolactam-based ionic liquids (CPILs) namely, Caprolactamium chloride, Caprolactamium methyl sulphonate, Caprolactamium trifluoromethane sulfonate, Caprolactamium acetate, Caprolactamium hydrogen sulphate and Caprolactamium trifluoromethane-acetate—for extraction of lipids from wet and dry Spirulina platensis microalgae biomass. Of these, the first three are novel CPILs. Methods The caprolactam-based ionic liquids (CPILs) were formed by a combination of caprolactam with different organic and inorganic Brønsted acids, and used for lipid extraction from wet and dry S. platensis microalgae biomass. Extraction of microalgae was performed in a reflux at 95 °C for 2 h using pure CPILs and mixtures of CPIL with methanol (as co-solvent) in a ratio of 1:1 (w/w). The microalgae biomass was mixed with the ILs/ methanol in a ratio of 1:19 (w/w) under magnetic stirring. Results The yield by control experiment from dry and wet biomass was found to be 9.5% and 4.1%, respectively. A lipid recovery of 10% from dry biomass was recorded with both caprolactamium acetate (CPAA) and caprolactamium trifluoroacetate (CPTFA), followed by caprolactamium chloride (CPHA, 9.3 ± 0.1%). When the CPILs were mixed with methanol, observable lipids’ yield enhancement of 14% and 8% (CPAA), 13% and 5% (CPTFA), and 11% and 6% (CPHA) were recorded from dry and wet biomass, respectively. The fatty acid composition showed that C16 and C18 were dominant, and this is comparable to results obtained from the traditional solvent (methanol-hexane) extraction method. The lower level of pigments in the lipids extracted with CPHA and CPTFA is one of the advantages of using CPILs because they lower the cost of biodiesel production by reducing the purification steps. Conclusion In conclusion, the three CPILs, CPAA, CPHA and CPTFA can be considered as promising green solvents in terms of energy and cost saving in the lipid extraction and thus biodiesel production process.

Liquid-liquid extraction of rare earth elements using systems that are more environmentally friendly: Advances, challenges and perspectives

• Alternative liquid–liquid techniques for rare earth extraction are reviewed. • Properties and green characteristics of alternative methods are assessed. • Comparisons with traditional solvent extraction method are presented. • Cloud point extraction demonstrates analytical pre-concentration method potential. • Aqueous biphasic systems demonstrate potential for large scale implementation. The rare earth elements, a group of metals consisting of the lanthanide series, together with yttrium and scandium, are increasingly important in high technology industries worldwide. Given the need to expand production of these elements, there is a search for processes to obtain them that are less environmentally damaging, since the rare earths production chain is associated with several environmental problems and concerns. Solvent extraction, one of the important steps involved in the obtaining of rare earth elements, is receiving much attention in the scientific and industrial community, with a renewed search for approaches that avoid the use of organic solvents. Among the various options, cloud point extraction and the use of aqueous two-phase systems are alternatives to the use of traditional organic solvents. This review considers these two more environmentally friendly techniques and their use for the extraction and/or separation of rare earth elements. The issues addressed include their potential to replace traditional liquid–liquid extraction, in terms of the efficiency, toxicity, and biodegradability of the components forming the systems, as well as their potential applications and future perspectives.

Design and application of online derivatization device for polar organics on atmospheric particulate filter

设计制作了一套用于气相色谱-质谱(GC-MS)分析极性有机物的在线衍生装置,并将其应用于大气颗粒物样品中极性有机物的检测。将大气颗粒物滤膜样品置于GC-MS进样口,通过使用套针组件,匀速引入气态衍生试剂N-甲基-N-(三甲基硅烷)三氟乙酰胺(MSTFA),使其在衬管内于310 ℃下与待测物接触,10 min即可完成硅烷化在线反应。反应过程中,色谱柱箱保持低温,衍生产物得以在柱头保留,反应完成后色谱柱箱程序升温,使衍生产物直接进行后续分离检测。应用在线衍生装置建立有机酸分析方法,获得了一元酸、二元酸、芳香酸、醇等极性有机物的检测信息,涵盖了大气化学分析常见的大部分目标化合物。该方法检出限为0.02~0.53 mg/L,线性相关系数为0.976~0.996,日内、日间RSD为0.27%~7.28%,适用于批量大气环境样品检测。与传统离线衍生技术相比,本装置使衍生反应处于高温惰性气体氛围,排除空气中水分对衍生试剂的损耗和衍生产物降解风险,反应稳定、效率高;固体滤膜上有机物进行热解吸的同时完成在线衍生,样品需求量小,操作简单,零有机试剂污染,并有望应用于醇类、酚类等多种极性有机化合物的分析。此外, 该装置搭建简单,可模块化设计,适用于不同品牌气相色谱仪,具有商业化推广前景。

A clean and efficient method for separation of vanadium and molybdenum by aqueous two-phase systems

The growing demand for vanadium and molybdenum in the high-tech industry has spurred researches into recycling from a variety of sources. A green and simple process for separation of vanadium and molybdenum was proposed by aqueous two-phase systems consisting of non-ionic surfactants (triblock copolymer, L35; octaphenyl polyoxyethylene, Triton X-100 and polyethylene glycol, PEG2000) and sodium sulfate without any extractant. The effects of aqueous pH, temperature, vanadium and molybdenum concentration，and different surfactants on separation performance of vanadium and molybdenum were systematically studied. The results indicated that the extraction rate of molybdenum and vanadium increased from 73% to 92% and from 11% to 30%, respectively, with increasing aqueous pH from 0.6 to 0.9. The extraction rate of vanadium decreased and the extraction rate of molybdenum increased with increasing temperature from 313.15 K to 343.15 K. Furthermore, with strengthening of molybdenum concentration from 1 g/L to 10 g/L and vanadium concentration from 1 g/L to 5 g/L, the extraction rate of vanadium and molybdenum increased. The sequence on separation efficiency of both metals is L35, Triton X-100 and PEG2000 from high to low. The extraction rate of molybdenum reached 91% and the extraction rate of vanadium was below 18% and the separation factor of both metals was above 47 under the optimal conditions of aqueous pH of 0.70–0.75 and extracting temperature of 343.15 K for L35 + Na2SO4 + H2O aqueous two-phase system. It has obvious advantages in terms of safety production, environmental protection compared with traditional organic solvent extraction method.

Ionic Liquid-Based Ultrasonic-Assisted Extraction Coupled with HPLC and Artificial Neural Network Analysis for Ganoderma lucidum.

Ganoderma lucidum is widely used in traditional Chinese medicine (TCM). Ganoderic acid A and D are the main bioactive components with anticancer effects in G. lucidum. To obtain the maximum content of two compounds from G. lucidum, a novel extraction method, an ionic liquid-based ultrasonic-assisted method (ILUAE) was established. Ionic liquids (ILs) of different types and parameters, including the concentration of ILs, ultrasonic power, ultrasonic time, rotational speed, solid–liquid ratio, were optimized by the orthogonal experiment and variance analysis. Under these optimal conditions, the total extraction yield of the two compounds in G. lucidum was 3.31 mg/g, which is 36.21% higher than that of the traditional solvent extraction method. Subsequently, an artificial neural network (ANN) was developed to model the performance of the total extraction yield. The Levenberg–Marquardt back propagation algorithm with the sigmoid transfer function (logsig) at the hidden layer and a linear transfer function (purelin) at the output layer were used. Results showed that single hidden layer with 9 neurons presented the best values for the mean squared error (MSE) and the correlation coefficient (R), with respectively corresponding values of 0.09622 and 0.93332.

Extraction optimization of accelerated solvent extraction for eight active compounds from Yaobitong capsule using response surface methodology: Comparison with ultrasonic and reflux extraction

This work described the development of a novel method for simultaneous extraction of eight active compounds (including catechin, albiflorin, paeoniflorin, ferulic acid, ginsenoside Rg1, tetrahydropalmatine, ginsenoside Rb1 and osthole) from Yaobitong capsule by accelerated solvent extraction (ASE). Response surface methodology (RSM) with desirability functions was employed to optimize the extraction conditions yielding the optimal conditions of ASE (extraction time 8 min, extraction temperature 80 °C, extraction solvent 70% methanol and flushing volume 100%). A high-performance liquid chromatography coupled with a diode array detector (HPLC-DAD) method was developed and validated for simultaneous quantification of the eight compounds in Yaobitong capsule. The values of correlation coefficient (R) were satisfactory between 0.9992 and 0.9999 over the linear concentration range of 0.5–1000 μg mL−1. It was found that the limits of detection (LODs) and the limits of quantification (LOQs) for the eight active compounds were 0.10–2.90 μg•mL−1 and 0.30–9.40 μg•mL−1, respectively. The recoveries of the eight main active compounds in Yaobitong capsule were in the range of 93.31%–106.22%. And the contents of the analytes extracted by ASE under the optimal conditions were compared to traditional solvent extraction methods, such as ultrasonic and reflux extraction. The results indicated that the ASE method proved to be more suitable for the extract of active compounds in Yaobitong capsule, which could obtain higher extraction efficiency. At last, the proposed method was applied to analyze ten batches of actual samples, which provided high extraction efficiency and had wide potential application in the analysis of traditional Chinese medicines.

Microwave-assisted Petroporphyrin Release from Asphaltene Aggregates in Polar Solvents

This work presents an efficient approach for the primary separation of the petroporphyrin component from asphaltene aggregates. The n-pentane asphaltenes separated from the vacuum residue of Canadian oil sands bitumen were used as the feedstock. The release behavior of petroporphyrins from feed asphaltenes in polar solvents with the assistance of microwave irradiation was investigated. UV–vis spectroscopy was utilized to calculate the petroporphyrin release efficiency (PRE). The effects of asphaltene concentrations and solvent properties on the PRE were discussed. Results show that, under the microwave irradiation, asphaltenes could be rapidly separated into soluble and insoluble fractions. The solubles are enriched with vanadyl porphyrins, while the insolubles present only weak absorption of nickel porphyrins at proper asphaltene concentrations. The dispersion force (fd) of solvents has a strong correlation with the PRE. Under the optimized conditions of the methanol/toluene volume ratio of 2:1, the microwave time of 10 min, and the asphaltene concentration of 0.08 g/L, the PRE can reach up to 45%. Compared with the traditional solvent extraction method, the PRE of this new method is improved prominently. The possible mechanism of selective activation of petroporphyrin motivated by the microwave irradiation and the formation of asphaltene vesicles is proposed. This work could provide a more efficient technique to purify petroporphyrins from asphaltenes and could give insight into the interactions between petroporphyrins and asphaltene aggregates.

Improved extraction of the natural anticancerigen pristimerin from Mortonia greggii root bark using green solvents and aqueous two-phase systems

Two green and sustainable strategies for pristimerin recovery from Mortonia greggii (Celastraceae) root bark were assayed using ionic liquids and ethanol-phosphate biphasic systems. The yields of pristimerin extraction with ionic liquids (1-ethyl-3-methylimidazolium acetate (EMIMAc) and 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4)) were lower than those obtained through a traditional solvent extraction method. Even more, the implantation of a BMIMBF4-phosphate Aqueous Two-Phase System (ATPS) did not improve the pristimerin recovery yield. Therefore, extractions in ATPS using mixtures of ethanol and phosphate salts considering as factors the extraction time and the number of extraction steps were performed. The obtained extract on the ethanol-rich phase showed a comparable pristimerin yield (7.16 ± 0.09 mg/g) and twice the purity (12.82 ± 0.42 mg/g) to that obtained in traditional solvent extraction (30 min) with a shorter (15 min) extraction time. The proposed methodology represents a feasible, scalable and environmentally-friendly procedure to obtain sufficient amounts of this natural anticarcinogenic compound for in vivo bioactivity assays.

Thermo-vaporization for decontaminating hydrocarbon source rocks

Although use of oil based mud (OBM) benefits drilling engineers, it creates complications for analyses and interpretations of geochemical samples. Pyrolysis of such samples frequently displays masking effects on the true pyrolysis Tmax (e.g., true maturity). When this phenomenon goes undetected, erroneously reported Tmax-based thermal maturity may wrongly influence exploration efforts. The consequences can be even more dramatic when such data is used for calibration of basin models that aim to reconstruct burial and temperature histories and determine hydrocarbon generation from source rock(s).Solvent extraction is generally an effective and commonly employed method for removal of solvent-soluble organic contaminants from samples, but it is expensive and time consuming. Here, we report a new and a faster method called “thermo-vaporization” (TV) that is capable of replacing solvent-extraction processes, thereby eliminating the need for lengthy solvent extraction. This can lead to further contamination. Careful thermo-vaporization conducted below kerogen cracking temperatures guarantees that the solid organic matter (kerogen) is not affected, excluding low level effects determined for immature sulfur-rich kerogen containing samples. The thermo-vaporization method saves time and reduces the potential effect of sample contamination. It provides a rapid workflow to assess thermal maturity with greater confidence.The study described in this article confirms that solvent extractable organic contaminants can be removed from samples by the novel thermo-vaporization method. The method is based on programmed pyrolysis and can be performed with a variety of available pyrolysis apparatus. After optimization, it was found that TV at 350 °C for 60 min or 375 °C for 30 min are both sufficient for removal of contaminants similar to the traditional solvent extraction method. A workflow for a thermo-vaporization based sample cleaning prior to pyrolysis is provided.