Conventional Solvents Research Articles

Primary Amine-Functionalized Chiral Covalent Organic Framework Enables High-Efficiency Asymmetric Catalysis in Water.

Aqueous asymmetric catalysis using chiral covalent organic frameworks (COFs) represents a significant advancement but remains to be explored. Herein, we present the first example of aqueous asymmetric catalysis catalyzed by a primary amine-tagged chiral D-ADP-TAPB COF. The D-ADP-TAPB COF was synthesized by the postsynthetic deprotection of D-ADP-TAPB-Boc bearing a protective tert-butoxycarbonyl (Boc) group, which was constructed by a Schiff-base reaction between an alanine-derived chiral building block (D-ADP-Boc) and 1,3,5-tris(4-aminophenyl)benzene (TAPB). The crystalline D-ADP-TAPB COF exhibits a uniform, spherical morphology with abundant, well-distributed chiral primary amines, rendering it highly active in the asymmetric aldol reaction between cyclohexanone and 4-nitrobenzaldehyde. Notably, this reaction is conducted entirely in water, achieving impressive yields and enantiomeric excess (ee) values of up to 90 and 85%, respectively. To the best of our knowledge, D-ADP-TAPB COF represents the first chiral COF catalyst with high reactivity and enantioselectivity for an asymmetric aldol reaction solely in water, eliminating the need for conventional organic solvents. Moreover, a plausible mechanism for D-ADP-TAPB COF-mediated aqueous asymmetric aldol reactions is elucidated. This work not only expands the toolbox for designing rare primary amine-functionalized chiral COFs for asymmetric catalysis but also opens exciting avenues for developing green and water-based enantioselective catalysis.

OPTIMIZATION ULTRASOUND-ASSISTED EXTRACTION USING CHOLINE CHLORIDE-BASED NATURAL DEEP EUTECTIC SOLVENT TO INCREASE PHENOLIC COMPOUNDS AND ANTIOXIDANTS FROM RHODOMYRTUS TOMENTOSA LEAVES

Objective: The main purpose of this study is to give recommendations for the ideal extraction conditions for improving the extraction yield and antioxidant activity of R. tomentosa leaves. Methods: First, the extraction total phenolic yields of five choline chloride-based Natural Deep Eutectic Solvents (NADES) were evaluated. Then, Box Behnken designs of Response Surface Methodology (RSM) were conducted in order to optimize the extraction condition. The extraction variables investigated were extraction time, water content in NADES, and solid-to-liquid ratio. Meanwhile, total phenolic and 2,2′-azinbis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) free radicals scavenging activity were used as responses. Results: NADES with combination of choline chloride and propylene glycol with a molar ratio of 1:1 was found to be the best solvent for extracting phenolic compound. The total phenolic compound obtained was 29.6351 mg GAE/g dried leaves with ABTS scavenging activity about 96.84% under the optimum extraction condition (extraction time of 60 min, 25% water content in NADES, and solid-to-liquid ratio of 0.02 g/ml). Better results were shown compared to extracts with conventional solvents. Conclusion: In sum, the use of choline chloride-based NADES as extraction solvent under optimum condition was proven to be effective in increasing the extraction efficiency of phenolic compounds and antioxidant activity from R. tomentosa leaves.

A Procedure for Solid-Phase Extractions Using Metal-Oxide-Coated Silica Column in Lipidomics.

Lipid enrichment is indispensable for enhancing the coverage of targeted molecules in mass spectrometry (MS)-based lipidomics studies. In this study, we developed a simple stepwise fractionation method using a titanium- and zirconium-dioxide-coated solid-phase extraction (SPE) silica column that separates neutral lipids, phospholipids, and other lipids, including fatty acids (FAs) and glycolipids. Chloroform was used to dissolve the lipids, and neutral lipids, including steryl esters, diacylglycerols, and triacylglycerols, were collected in the loading fraction. Second, methanol with formic acid (99:1, v/v) was used to retrieve FAs, ceramides, and glycolipids, including glycosylated ceramides and glycosylated diacylglycerols, by competing for affinity with the Lewis acid sites on the metal oxide surface. Finally, phospholipids strongly retained via chemoaffinity interactions were eluted using a solution containing 5% ammonia and high water content (45:50 v/v, 2-propanol:water), which canceled the electrostatic and chelating interactions with the SPE column. High average reproducibility of <10% and coverage of ∼100% compared to those of the non-SPE samples were demonstrated by untargeted lipidomics of human plasma and mouse brain, testis, and feces. The advantage of our procedure was showcased by characterizing minor lipid subclasses, including dihexosylceramides containing very long-chain polyunsaturated FA in the testis, monogalactosyl and digalactosyl monoacylglycerols in feces, and acetylated and glycolylated derivatives of gangliosides in the brain that were not detected using conventional solvent extraction methods. Likewise, the value of our method in biology is maximized during glycolipidome profiling in the absence of neutral lipids and phospholipids that cover more than 80% of the chromatographic peaks.

Concurrently Improving both Mechanical and Electrochemical Performances of Quasi-Solid-State Electrical Double-Layer Capacitors by a Rational Design of Gel Polymer Electrolytes.

Aqueous poly(vinyl alcohol) (PVA) gel electrolyte-based quasi-solid-state electrical double-layer capacitors (QSEDLCs) have been extensively investigated in the past ten years, but challenges remain to fabricate the PVA gel electrolyte possessing both superior mechanical and outstanding electrochemical performances. Herein, we develop a strategy to address this issue by a rational design of PVA gel electrolytes, based on a combination of the freeze-thaw (FT) method and sodium perchlorate (NaClO4)-based water-in-salt (WIS) electrolyte. Our study demonstrates that either the FT method or the NaClO4-based WIS electrolyte can improve both the mechanical performance of the PVA gel electrolyte by increasing the crystallization of PVA chains and the electrochemical performance of the PVA gel electrolyte-based QSEDLC by different mechanisms. In comparison with the conventional solvent evaporation method, this work provides an effective strategy to concurrently improve both the mechanical and electrochemical performances of aqueous QSEDLCs.

Eco-friendly solvents in liquid-liquid microextraction techniques for biological and environmental analysis: a critical review.

In recent years, green solvents have emerged as promising alternatives in the field of analytical chemistry, replacing conventional organic solvents known for their toxicity, volatility, and flammability. The combination of these solvents with liquid-liquid microextraction techniques has facilitated the development of simpler, faster, more economical, and environment-friendly methodologies for the analysis of samples of varying complexity. This review discusses the fundamental physicochemical properties and advantages of using deep eutectic solvents, ionic liquids, switchable-hydrophilicity solvents, supramolecular solvents, and surfactants as extractants. Furthermore, analytical methods based on liquid-liquid microextraction techniques developed in the last 5years for the determination of organic compounds and metals in biological and environmental samples are presented and discussed, highlighting their applications and benefits to improve analytical performance and sustainability.

Evaluation of the Thermal and Light Stability of β-Carotene Extracted from Mauritia flexuosa Using Ionic Liquid

The growing concern over the adverse effects of synthetic dyes has generated interest in the use of natural pigments by the food industry. β-carotene, a carotenoid found in various plant sources, is recognized for its antioxidant properties and provitamin A activity. The fruit of the buriti palm (Mauritia flexuosa), which is particularly rich in β-carotene, serves as a significant natural source of this pigment. This study aimed to extract β-carotene from buriti fruit using ionic liquids as an alternative to conventional organic solvents like acetone. β-carotene content was determined by HPLC and showed that extraction with [C4mim] [BF4] not only improved β-carotene extraction efficiency compared to acetone (19.21 and 13.13 mg/100 g, respectively) but also provided greater pigment stability during light, thermal and color stability tests. Moreover, ionic liquids are aligned with the principles of green chemistry and offer a sustainable and safe alternative for the food industry. Its favorable characteristics not only reduce environmental impacts associated with conventional solvents, but also ensure an increase in the shelf life of natural dyes, thus promoting the safety and quality of food products.

Solubility and extractability enhancement of the main food flavonoids by using choline chloride-based natural deep eutectic solvents

This study investigates the solubility of ten primary food flavonoids in both conventional solvents and natural deep eutectic solvents (NADES), utilizing five choline chloride-based NADES. These NADES were formulated with lactic acid, ascorbic acid, urea, sorbitol, and 1,2-propanediol as hydrogen bond donors (HBD). Conventional solvents used in the comparison included water, menthol, and ethanol. The flavonoids studied—catechin, daidzein, quercetin, naringenin, luteolin, genistein, kaempferol, apigenin, diosmetin, and chrysin—were analyzed for solubility and extractability via both solvents. Flavonoid solubility was observed to vary based on both the structural characteristics of the flavonoid and the choice of HBD. Notably, catechin demonstrated the highest solubility across all solvent systems, followed by naringenin and quercetin. Among the NADES systems, the blend based on 1,2-propanediol notably enhanced the solubility of quercetin and luteolin to 53.4 mg/mL and 26.9 mg/mL, respectively, surpassing their solubility in conventional solvents. The empirical findings were consistent with theoretical predictions made using the COSMO-RS method, confirming the efficacy of NADES in solubilizing food flavonoids more effectively than conventional solvents.

Unleashing the potential of castor oil as extraction solvent of carotenoids from tomatoes

Adding carotenoids to cosmetic formulations aligns with the industry’s growing ethos of producing safer, more sustainable, and nature-inspired products. While synthetic compounds still have their place in cosmetics, the shift towards natural ingredients such as carotenoids reflects a more significant commitment across the industry to satisfy consumer preferences and contribute to a greener future. Castor oil is a well-known natural oil used in several cosmetic formulations because it reduces moisture loss and enhances skin hydration. However, it’s only added to cosmetics simultaneously with all the other components, including natural extracts. Thus, this work goes behind literature and classic downstream approaches. A simplification of cosmetics formulations is intended by using castor oil directly as the extraction solvent of natural bioactive compounds, such as carotenoids from tomatoes. A comparison of its extraction performance with conventional extraction solvents was made, and all the process operating conditions were optimized (SLR = 0.06 gbiomass.mLsolvent-1, percentage of castor oil = 50 % (v/v), and time of extraction = 90 min) to achieve a maximum recovery of 3.2 ± 0.2 mgCar.gbiomass-1. Additionally, its capacity as a preservative of carotenoids degradation was also tested against a conventional solvent to enhance natural pigments’ shelf life showcasing increased stability (especially at 75 °C), a current problem of their application in industry. The environmental performance of the process proposed was analyzed based on the carbon footprint, with electricity consumption identified as the most significant contributor. This impact could be greatly reduced by utilizing photovoltaic energy. Lastly, a conceptual process design has been proposed to envision its practical application in an industrial setting.

Direct Extraction of Lipids, β-Carotene, and Polyphenolic Compounds from Wet Microalga Dunaliella salina by Liquefied Dimethyl Ether.

Extraction of lipids and high-value products from highly wet microalgae requires significant energy for the drying pretreatment. In this study, we examined the direct extraction of lipids, β-carotene, and polyphenolic compounds from wet Dunaliella salina using liquefied dimethyl ether (DME), which is effective in lipid extraction for biofuel production. The amount of DME-extracted β-carotene was 7.0 mg/g, which was higher than that obtained from the chloroform-methanol extraction. Moreover, the total phenolic content extracted with DME and its antioxidant capacity were slightly higher than those extracted with chloroform-methanol. DME removed almost all the water and extracted 29.2 wt% of total lipids and 9.7 wt% of fatty acids. More lipids were extracted from wet samples by liquefied DME than by chloroform-methanol extraction. The C/N ratio of lipids extracted with DME was 112.0, higher than that of chloroform-methanol. The high C/N ratio suggests that nitrogen-containing phosphatidylcholines may be less easily extracted by liquefied DME and may be highly selective. However, the ratio of saturated fatty acids was 34.8%, lower than that of chloroform-methanol. Na+ and Mg2+ in the culture medium were not extracted using DME. Thus, using the extract with DME has both advantages and disadvantages compared to using the extract with chloroform-methanol; however, it has satisfactory extraction properties. DME is expected to be an environment-friendly alternative solvent because it does not require drying, which is necessary for conventional extraction solvents.

Optimizing liquid-liquid extraction: comparing ultrasound-assisted and conventional solvent techniques for molybdenum with N-(2-Hydroxybenzylidene) aniline

Optimizing liquid-liquid extraction: comparing ultrasound-assisted and conventional solvent techniques for molybdenum with N-(2-Hydroxybenzylidene) aniline

Leveraging conventional and natural solvents: physical extraction of 4-hydroxybenzoic acid

Leveraging conventional and natural solvents: physical extraction of 4-hydroxybenzoic acid

Valorisation of white wine lees: optimisation of subcritical water extraction of antioxidant compounds

This study explored the extraction of antioxidant compounds from white wine lees using subcritical water extraction (SWE). First, SWE was compared to extraction using conventional solvents mixed with water: 50 % methanol, 50 % ethanol and 50 % acetonitrile. The antiradical activity of the extract increased to 12.8 mg TE/g of extract dry matter (DM) using conventional solvents and to 29.2 mg TE/g DM with SWE, compared to the antiradical activity of dried lees, which was 5.7 mg Trolox Equivalent/g of dry matter (mg TE/g DM). Second, SWE conditions were optimised to obtain lees extracts with a high antioxidant activity by applying a Doehlert design and response surface methodology (RSM). The extraction parameters modulated during RSM optimisation were extraction time (t, 15 – 60 min), temperature (T, 100 – 250 °C) and stirring speed (S, 100 – 1000 RPM). Antioxidant activity was assessed using DPPH and FRAP tests, as well as by measuring the Oxygen Consumption Rate (OCR) of lees extracts. Temperature was found to be the main parameter that had a significant effect on antioxidant activity. The results of the RSM showed the optimal conditions (temperature, duration and speed) for attaining maximum antioxidant activity to be: 240 °C, 15 min and 550 RPM respectively. The best-known antioxidant compounds in white wine lees, Total Polyphenol Content (TPC), Glutathione (GSH) and Total Sulfhydryl groups (TSH) were also quantified. Extracts with the highest antioxidant capacity had the highest TPC and TSH concentrations. In conclusion, this study showed (i) that subcritical water extraction is a green process that has potential as an alternative to using conventional solvents for extracting white wine lees, (ii) the chemical components involved in their antioxidant capacity, and (iii) the potential of the lees for oenological and other industrial applications.

Optimizing alginate extraction using Box-Behnken design: Improving yield and antioxidant properties through ultrasound-assisted citric acid extraction

The Box-Behnken Design was employed to optimize the extraction of alginate (ALG) from Sargassum cymosum C. Agardh using ultrasound-assisted treatment and substituting hydrochloric acid with citric acid during the acidic step. The study aimed to maximize yield and enhance the functional properties of the polysaccharide. The effects of pH of the citric acid (CA) solution, ultrasound power, and treatment time were evaluated in terms of yield, viscosity-average molecular weight (Mw), dynamic viscosity (µdyn), and antioxidant capacity (AC) of the ALG. The optimized conditions (176 W, 15 min, pH 1) resulted in a yield of 54.20 %, Mw of 202.56 kDa, µdyn of 10.43 mPa•s, and AC of 80.81 µM Trolox g-1. The lowest pH was found to be optimal for enhancing alginate extraction efficiency and improving its properties (viscosity and antioxidant capacity). Under optimized conditions, the CA solution resulted in a higher ALG yield with minimal changes in Mw and µdyn, while also retaining the main functional groups and chemical bonds, and doubling the AC compared to hydrochloric acid. The results indicate that ultrasound-assisted extraction is a promising method for extracting alginate from brown algae and that CA can satisfactorily replace the conventional solvent used in the acidic treatment.

Simultaneous rare earth sulfate transformation and carbon dioxide mineralization

The wet metallurgical process route for recovering rare earth elements usually uses sulfuric acid. To obtain marketable individual rare earth products, converting rare earth sulfates to chlorides is essential. Conventional chemical precipitation and solvent extraction methods result in significant amounts of ammonia wastewater and greenhouse gas emissions. Therefore, we propose a novel process that integrates CO2 mineralization with rare earth sulfates transformation. By utilizing a base-catalyzed mechanism with trioctylamine (TOA), CO2 is effectively employed for selective precipitation of more than 95 % of rare earths from magnesium and calcium under optimized conditions. Subsequently, dissolution in hydrochloric acid allows for enrichment of the concentration of rare earths up to 188.3 g/L. The reaction mechanism is examined through Visual MINTEQ simulations and various analytical techniques. This process not only offers a sustainable approach to rare earth sulfates transformation but also contributes to carbon capture, utilization, and sequestration efforts.

Investigating the impact of solvent extraction parameters on oil yield and oil properties: a review

Oilseeds are rich in fatty acids, proteins, fibers, minerals, and vitamins that are necessary for human health. It mainly comprises triglycerides and other minor components, including phytosterols, phenols, carotenoids, tocopherols, and phospholipids. Oils can be extracted using a variety of extraction methods including but not limited to the conventional mechanical and solvent method, and novel methods like supercritical fluid extraction. However, the quality and quantity of extracted oil depends on the process parameters. Among many process parameters temperature is the main parameter which controls the yield and its quality. Temperature range depends upon the nature and type of oilseed. High temperature leads to increased yield while relatively low temperature results in low oil yield and longer extraction time. Large particle size of the solid creates a temperature gradient between the inner and outer surface of the seeds which in turn lowers oil yield. Based on this review, an extraction temperature slightly below the boiling point of the solvent is recommended.

Bioactivity and application potential of O/W emulsions derived from carboxylic acid-based NADES-extracted total saponins from Polygonatum cyrtonema Hua

This study focuses on evaluating new methods for the green extraction of saponin compounds from Polygonatum cyrtonema Hua (PCH). This study utilized a combination of carboxylic acid-based natural deep eutectic solvents (NADES) and various extraction techniques including conventional heat reflux-, ultrasound-, and microwave-assisted extraction. The primary objectives were to assess total saponin yield, antioxidant capacity, and enzyme inhibition efficiency. Additionally, the solvents and extracts were evaluated for their antibacterial activity. Oil-in-water (O/W) emulsions of NADES extracts were also characterized and analyzed for stability. Results indicated that three NADES systems were effective in extracting saponins, with choline chloride and lactic acid (ChCl-LA) system being the most efficient. The ChCl:LA extract exhibited antimicrobial and antioxidant activities superior to conventional organic solvent extracts. Additionally, it demonstrated maximum inhibitory activity (IC50 values: 0.98 ± 0.03 and 1.46 ± 0.07 mg/mL, respectively) against α-glucosidase and α-amylase. The NADES extract as an aqueous phase significantly improved the stationarity of the O/W emulsion. Collectively, the study highlights the antimicrobial and technological advantages of NADES as a potential solvent for extracting saponin compounds from PCH.

Using natural deep eutectic solvents for the extraction of antioxidant compounds from cornelian cherry (Cornus mas L.) fruits

Traditionally used extraction methods are usually based on toxic and/or flammable solvents. Therefore, currently, increased attention has been focused on environmentally friendly green extraction techniques. We aimed to develop a green extraction procedure by using natural deep eutectic solvents (NADES) to recover antioxidant compounds from cornelian cherry fruits (Cornus mas L.). Natural deep eutectic systems combined with maceration with shaking extraction were tested to recover of antioxidant compounds from cornelian cherry fruits. In this study, four different independent variables, namely solvent type (Glu-CA; Glu-Gly; LA-Glu), water concentration (30, 50, and 70 %; v/v), extraction time (30, 60, 90, and 120 min), and extraction temperature (25, 40, and 50 °C) were investigated. Glucose-glycerin (Glu-Gly; 1:1 M ratio) based solvent provided the best results. In addition, one-factor-at-a-time (OFAT) optimization showed that a temperature of 25 °C, 120 min of extraction time, and water concentration of 50 % (v/v) to be the best extraction parameters for Glu-Gly based NADES extraction. The developed method has been successfully applied for the extraction of antioxidant compounds from 13 different cornelian cherry cultivars. NADES can be used safely to extract phenolic compounds from cornelian cherry fruits compared to conventional extraction solvents (water and 80 % (v/v) ethanol).

Chemical-Functional Analysis of Extracts Obtained from Zuccagnia punctata Powder Using Green Solvents (NaDESs) in Conjunction with Traditional and Non-Traditional Techniques.

Zuccagnia punctata Cav. (Family Fabaceae. Subfamily Caesalpinioideae) is a native plant species with a long history of use in Argentine traditional medicine. The purpose of the present study was to extract bioactive compounds with antioxidant and antifungal activity from Z. punctata aerial parts using conventional solvents (water, ethanol 60°, vegetal oil) and unconventional solvents (natural deep eutectic solvents or NaDESs) such as green solvents with and without the assistance of ultrasound (UAE) and microwaves (MAE). NaDESs such as glucose: lactic acid (LGH), sucrose: citric acid (CAS), choline chloride: urea (CU) and glucose: fructose: sucrose (FGS) were used. LGH and CU were effective in the extraction of phenolic compounds (6710 ± 10.12 µg GAE/mL and 7140 ± 15.00 µg GAE/mL, respectively) as well as ethanol (6270 µg ± 12.00 µg GAE/mL) using conventional methods. Two chemical markers of Z. punctata (2',4'-dihydroxychalcone and 2',4'-dihydroxy -3-methoxychalcone) were extracted in a high proportion in ethanol, oil, LGH and CU with UAE. The ABTS antioxidant capacity was higher in the extracts obtained with LGH and CU (SC50: 0.90 ± 0.10 µg GAE/mL and 1.08 ± 0.16 µg GAE/mL, respectively). The extract obtained with vegetal oil was the most potent as antifungal, followed by the extracts in ethanol, LGH and CU. These findings highlight the importance of using environmentally friendly solvents such as NaDESs to obtain bioactive metabolites from Z. punctata, an endemic plant of Argentina with a potential application in the food, cosmetic and pharmaceutical industries.

Extraction of apple pomace polyphenols using natural deep eutectic solvents: A sustainable approach

To effectively utilize apple pomace resources, we extracted apple pomace polyphenols using natural deep eutectic solvent (NADES) as the medium, with a solvent-to-solid ratio of 50 mL/g, for a duration of 120 min. Compared to conventional extraction solvents (ethanol and methanol), four NADES significantly enhanced the extraction efficiency of polyphenols from apple pomace. Notably, NADES 1 (betaine: urea = 1:1, 30% water) and NADES 2 (betaine: malic acid = 1:1, 30% water) exhibited superior extraction capabilities, with maximum values reaching 5.245 ± 0.124 mg GAE/g pomace and 5.157 ± 0.164 mg GAE/g pomace, respectively, in Qinguan apple pomace. Both solvents reached their maximum extraction efficiency within 120 min, with NADES 1 achieving a maximum extraction amount of 4.8325 mg GAE/g and NADES 2 achieving 5.3039 mg GAE/g from Fuji apple pomace. NADES 1 and NADES 2 were more efficient in extracting monophenols such as quercetin, rutin, gallic acid, and procyanidin, whereas organic solvents (methanol and ethanol) were more effective for monophenols like methyl gallate and phlorizin. Furthermore, polyphenol extracts obtained using NADES from Fuji apple pomace displayed varying levels of antibacterial effectiveness, with NADES 4 (glucose: lactic acid = 1:5, 60% water) and NADES 2 showing superior efficacy against Escherichia coli and Staphylococcus aureus. This comprehensive study not only demonstrated the potential of NADES in extracting polyphenols from apple pomace but also highlighted their applicability as natural preservatives in the food industry.

Using Diglycolamide Extractants in an Imidazolium-Based Ionic Liquid for Rare Earth Element Extraction and Recovery.

Growing demands for rare earth elements (REEs) have prompted sustainability concerns worldwide. Given the need for sustainable extraction methods amidst REEs, ionic liquids (ILs) have been investigated as tunable extraction substitutes for conventional organic solvents, offering negligible volatility and diverse physical and chemical properties. Recent reports have shown that the introduction of extractants, like N,N,N',N'-tetraoctyldiglycolamide (TODGA) or N,N-dioctyldiglycolamic acid (DODGAA), into ILs can provide high selectivity and affinity for REE capture. Precipitate formation has been observed in IL-extractant systems across several studies; however, the molecular interactions that drive this phenomenon have yet to be explored. This study investigates the coordination environment in the precipitate formed between [Yb3+], DODGAA, and the 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM+][PF6 -]) IL. The composition of the precipitate was confirmed using several spectroscopic techniques and revealed an underlying hydrogen bonding interaction between the fluorine atom of [PF6 -] anion and -OH of the Yb-DODGAA complex. Computational studies were also conducted to examine the coordination environment of the Yb-TODGA and Yb-DODGAA complexes. The binding affinity of the extractants toward [Yb3+] is analyzed by calculating the associated binding energy values. The results clearly show a stronger binding affinity of the extractants toward [Yb3+], supporting the observed high extraction efficiencies of DODGAA and TODGA.