Three-level Orthogonal Array Design Research Articles

Supercritical Fluid Extraction of Pyrrolidine Alkaloid from Leaves of Piper amalago L.

Supercritical fluid extraction was used to extract the alkaloid N-[7-(3′,4′-methylenedioxyphenyl)-2(Z),4(Z)-heptadienoyl]pyrrolidine from leaves of Piper amalago L. A three-level orthogonal array design matrix, OAD OA9(34), was used for optimization of the parameters of supercritical extraction of the alkaloid, employing supercritical carbon dioxide: extraction time (20, 40, and 60 min), temperature (40, 50, and 60°C), pressure (150, 200, and 250 bar), and the use of cosolvents (ethanol, methanol, and propyleneglycol). All parameters had significant effect on the alkaloid yield. The alkaloid yield after 60 min of extraction without cosolvents at 9 different conditions (32) in terms of temperature (40, 50, and 60°C) and pressure (150, 200, and 250 bar) was also evaluated. The optimal yield (≈3.8 mg g−1) was obtained with supercritical CO2 + methanol (5% v : v) at 40°C and 200 bar for 60 min of extraction.

Role of combinatorial environmental factors in the behavior and fate of ZnO nanoparticles in aqueous systems: A multiparametric analysis

To better understand the environmental behavior, fate, and exposure risks of engineered nanoparticles in aquatic systems, for the first time, combinatorial aqueous systems were established using three-level orthogonal array design (OAD), an OA27 (313) matrix, to assess the effects of six co-varying environmental factors (organic acid type, organic acid concentration, NP concentration, pH, salt content, and electrolyte type) on the aggregation of commercial zinc oxide nanoparticles (ZnO NPs, mean diameter ∼41nm). A separate set of OA27 (313) experiments including temperature was conducted for the dissolution of these NPs. The results showed that the organic acid concentration and the pH were the most significant factors (p<0.001) influencing aggregation and dissolution of ZnO NPs, respectively. The electrolyte type and the salt content were the next most important factors in both the aggregation and dissolution. Based on the kinetics study of the aggregation, a high rate of the NP aggregation resulted in decreased dissolution, such that observed in the presence of calcium chloride. Clear temperature-induced aggregation and reduced dissolution were further observed with increasing temperature. This approach demonstrates that the behavior of ZnO NP may vary substantially under combinatorial environmental conditions.

Supercritical fluid extraction and characterisation of Moringa oleifera leaves oil

This work was aimed to extract and characterise the Moringa oleifera leaves oils using supercritical fluid extraction (SFE) and to compare the results against those obtained using the conventional Soxhlet extraction method. The oils extracted were analysed using GC–MS. The compounds were identified according to their retention indices and mass spectra (EI, 70eV). The effects of pressure (30MPa, 40MPa, 50MPa), temperature (40°C, 60°C, 80°C) and extraction time (60min, 90min and 120min) on the oil yield were investigated using a three-level orthogonal array design. The experimental results showed that while the oil yield increased with increasing any of the three parameters, temperature had the most significant effect. The highest yield of 6.34% was obtained under the condition of pressure 50MPa, temperature 60°C and an extraction time of 120min. The Soxhlet extraction was performed at 78°C for 8h using hexane as the solvent. A total of 42 compounds were identified in the Soxhlet extracted oil while only 12 compounds were detected in the SFE extracted oil. Some compounds that were found in the Soxhlet extracts were not detected in the SFE samples. This is because the supercritical fluid extraction is more selective than the Soxhlet extraction method. The compositions of the oil extracted by SFE under the different conditions examined were mostly similar and the major compounds identified were 1,2-Benzenedicarboxylic acid, mono (2-ethylhexyl) ester, nonacosane, heptacosane, β-Amyrin, although their quantities differed.

Efficient hydrophobization and solvent microextraction for determination of trace nano-sized silver and titanium dioxide in natural waters

Hydrophobic silver and titanium (IV) oxide nanoparticles (commercial Ag and TiO2 NPs with average particle sizes of 17 and 19nm, respectively) were quantitatively transferred into organic phase in natural water samples. Five NP surface modification and solvent extraction agents (reagents) types, mercaptocarboxylic acid, alkylamine, mediator solvent, extraction solvent, and surfactant, were investigated and optimized with three-level orthogonal array design (OAD), an OA27 (313) matrix. The most favorable reagents and experimental conditions were then examined. The best extraction efficiencies of 78.6 and 73.7% were obtained for 1mgL−1 citrate-stabilized Ag and TiO2 NPs, respectively, with 0.5mM of 11-mercaptoundecanoic acid, 1.5mM of octadecylamine, 1mL of methanol, 150μL of cyclohexane, 0.05mM of tetra-n-octylammonium bromide, pH=8.0, adsorption time of 2h, sonication time of 3min, and centrifugation time of 10min. Enrichment factors were 97 and 83, for Ag and TiO2 NPs, respectively. The optimum extraction conditions were successfully applied to genuine water samples at spiking levels of 2–100μgL−1 of Ag and TiO2 NPs. The relative recoveries of (69.0–85.1)% and (61.5–78.5)% were obtained for Ag and TiO2 NPs, respectively. The extracted surface-modified NPs were characterized with transmission electron microscopy, selected area electron diffraction, energy-dispersive X-ray, ultraviolet–visible, and Fourier transform infrared spectroscopic techniques. Based on the results, efficient ligand exchange and acid–base pair formation were observed on the NP surface without significant change in its original properties. The organic phase was microwave digested, and analyzed with inductively coupled plasma (ICP) optical emission spectroscopy and ICP mass spectrometry (ICP-MS). Detection limits of ICP-MS analyses of Ag and TiO2 NPs were 0.02 and 0.07μgL−1, respectively.

Comparison of Essential Oil Composition of Eucalyptus Oleosa Obtained by Supercritical Carbon Dioxide and Hydrodistillation

Essential oil of Eucalyptus oleosa, cultivated in Iran, was obtained by hydrodistillation and supercritical (carbon dioxide) extraction methods. The effects of supercritical carbon dioxide extraction parameters such as pressure, temperature, dynamic extraction time and modifier volume on the extraction efficiency were investigated by the three-level orthogonal array design. Regarding the percentages of α-pinene and 1,8- cineole, the optimum supercritical fluid extraction (SFE) results were obtained at the following experimental conditions: pressure = 100 atm, T = 45°C, dynamic time = 25 min, and Vmodifier = 2 mL. The composition of the extracts obtained from E. oleosa using supercritical fluid extraction was compared with the essential oil obtained by hydrodistillation. The composition of the SFE products was markedly different from the corresponding hydrodistillated oil.

Chemometric Analytical Approach for the Cloud Point Extraction and Inductively Coupled Plasma Mass Spectrometric Determination of Zinc Oxide Nanoparticles in Water Samples

Cloud point extraction (CPE) with inductively coupled plasma mass spectrometry (ICPMS) was applied to the analysis of zinc oxide nanoparticles (ZnO NPs, mean diameter ~40 nm) in water and wastewater samples. Five CPE factors, surfactant (Triton X-114 (TX-114)) concentration, pH, ionic strength, incubation temperature, and incubation time, were investigated and optimized by orthogonal array design (OAD). A three-level OAD, OA(27) (3(13)) matrix was employed in which the effects of the factors and their contributions to the extraction efficiency were quantitatively assessed by the analysis of variance (ANOVA). Based on the analysis, the best extraction efficiency (87.3%) was obtained at 0.25% (w/v) of TX-114, pH = 10, salt content of 15 mM NaCl, incubation temperature of 45 °C, and incubation time of 30 min. The results showed that surfactant concentration, pH, incubation time, and ionic strength exert significant effects on the extraction efficiency. Preconcentration factors of 62 and 220 were obtained with 0.25 and 0.05% (w/v) TX-114, respectively. The relative recoveries of ZnO NPs from different environmental waters were in the range 64-123% at 0.5-100 μg/L spiked levels. The ZnO NPs extracted into the TX-114-rich phase were characterized by transmission electron microscopy (TEM) combined with energy-dispersive X-ray spectroscopy (EDS) and UV-visible spectrometry. Based on the results, no significant changes in size and shape of NPs were observed compared to those in the water before extraction. The extracted ZnO NPs were determined after microwave digestion by ICPMS. A detection limit of 0.05 μg/L was achieved for ZnO NPs. The optimized conditions were successfully applied to the analysis of ZnO NPs in water samples.

Identification of volatile compounds of Atractylode lancea Rhizoma using supercritical fluid extraction and GC–MS

Supercritical fluid was used to extract volatile components from the rhizoma of Atractylode lancea (A. lancea). An orthogonal array design (OAD), L(9) (3)(4), was employed as a chemometric method for the optimization of the supercritical fluid extraction (SFE) of volatile compounds from the herbal medicine. Four parameters, namely, pressure, temperature, dynamic extraction time, and flow rate of CO(2), were studied and optimized by a three-level OAD in which the interactions between the parameters were neglected. These compounds were identified according to their retention times and mass spectra by GC-MS. A total of 30 compounds of SFE extracts were identified. Atractylon (8.63%), hinesol (1.44%), beta-eudesmol (6.64%), elemol (0.42%), and atractydin (13.92%) were the major sesquiterpenes identified in A. lancea SFE extracts.

Extraction of Cuminum cyminum essential oil by combination technology of organic solvent with low boiling point and steam distillation

Abstract Extraction of essential oil from Cuminum cyminum seeds using a combination of organic solvent with low boiling point and steam distillation was explored. The effect of different parameters, such as particle size (40, 60, 80 mesh), temperature (°C) 10, 15, 20 and extraction time (3, 5, 8 h), on the extraction yield was investigated using three-level orthogonal array design. The experimental results showed that the temperature had the largest effect on the yield of the extract (oleoresin), followed by extraction time and particle size. The optimum parameters, such as temperature, particle size, and extraction time were in turn 20 °C, 80 mesh, and 8 h. Essential oil of C. cyminum seeds obtained by supercritical fluid extraction (SFE), hydrodistillation (HD), combination technology of organic solvent with low boiling point and steam distillation (OS-SD) were further analysed by gas chromatographic/mass spectrometric detection to compare the extraction methods. Forty-five compounds in the C. cyminum essential oil were identified, showing that the composition of the extraction by different methods was mostly similar, whereas relative concentration of the identified compounds was apparently different. General characteristics of the C. cyminum essential oil obtained by different methods were further compared, and OS-SD was considered as the optimum process among the three processes to obtain C. cyminum essential oil for high quality, simple technology and low cost.

Supercritical fluid extraction of monoamine oxidase inhibitor from antler velvet

Supercritical fluid extraction (SFE) of the monoamine oxidase (MAO) inhibitor from antler velvet with CO 2 was explored. The effect of different parameters, such as particle size, the kind of co-solvent, extraction temperature and pressure, on the extraction yield ( Y) and the total inhibitory activity (TI) on MAO-B were investigated using three-level orthogonal array design. The experimental results show that when the absolute ethanol as co-solvent was used and the particle size was 120 μm, the extraction temperature was 70 °C, the extraction pressure was 30 MPa, the extract yield reached 3.58% and the TI of the extract was 3319.13 U/g. Evaluation of the inhibitory activity of extract on MAO indicated that the extracts had strong inhibitory effects on MAO-B, but had slight effects on MAO-A. The MAO-B activity was inhibited by 93.77% at the concentration of 278.15 mg/L, which was much higher than that of water extract and ethanol extracts. The compositions of estradiol, uracil, hypoxanthine, p-hydroxybenzaldehyde and phospholipids in the SFE extracts were identified, which were reported to have the inhibitory effect on MAO.

Optimization of supercritical fluid extraction of dl-tetrahydropalmatine from rhizome of Corydalis yanhusuo W.T. Wang with orthogonal array design

dl-Tetrahydropalmatine ( dl-THP), an alkaloid occurring in plant, has been intensively studied due to its pharmacological actions. In this report, dl-THP from rhizome of Corydalis yanhusuo W.T. Wang was extracted using supercritical fluid extraction (SFE). Determinations of the extracts were performed by high-performance liquid chromatography. An orthogonal array design (OAD), OA 9(3 4), was employed for optimization of supercritical fluid extraction of parameters of the compound. Four factors, namely various modifiers, the dynamic extraction time, temperature and pressure of the supercritical fluid, were studied and optimized by a three-level OAD. The effects of the parameters on the yield of dl-THP were studied using analysis of variance (ANOVA). Temperature had significant effect on the yield of dl-THP, while the other three factors, i.e. various modifiers, dynamic extraction time and pressure, were not identified as significant factors under the selected conditions, based on ANOVA. The result shown that the optimization for the extraction condition of dl-THP was 1,2-propanediol used as modifier of supercritical CO 2, extraction time 60 min, temperature 70 °C and pressure 200 bar, and that higher yield (1.324 mg/g) was obtained than that obtained by the other extraction condition.

Supercritical fluid extraction of ecdysterone from the roots of Achyranthes bidentata BL.

Ecdysterone has been found in a great many plants and animals and has some valuable pharmaceutical properties. The present study was conducted to investigate optimal conditions for the extraction of the compound by supercritical fluid extraction from the roots of Achyranthes bidentata BL. An orthogonal array design (OAD), OA(9)(3(4)), was employed as a chemometric method for optimization of the extraction of ecdysterone from the herbal medicine. Four parameters, namely, pressure and temperature of the supercritical fluid, the dynamic extraction time, and the flow rate of dimethyl sulfoxide, were studied and optimized by a three-level OAD. Determinations of the extracts were performed by high-performance liquid chromatography. The effects of the parameters were studied using analysis of variance. The results shown that the yield of ecdysterone could be influenced by the four parameters to a similar degree. The yield for DMSO-modified supercritical CO(2) was in the range from 0.65 to 1.03 mg/g under the selected conditions. In comparison with methanol-modified supercritical CO(2 )and Soxhlet extraction, a higher yield was obtained when DMSO-modified supercritical CO(2) was used.

Extraction of essential oil from Pimpinella anisum using supercritical carbon dioxide and comparison with hydrodistillation

Supercritical fluid extraction (SFE) of essential oil from Pimpinella anisum, using carbon dioxide as a solvent is presented in this work. An orthogonal array design OA9 (34) was applied to select the optimum extraction condition. The effects of pressure, temperature, dynamic extraction time and methanol volume on the extraction efficiency were investigated by the three-level orthogonal array design. Results show that pressure has a significant effect on the extraction efficiency. The extract obtained from P. anisum by using supercritical fluid extraction was compared with the essential oil obtained by hydrodistillation, considering both quantity and quality of the product. SFE products were found to be of markedly different composition, compared with the corresponding hydrodistilated oil. The total amount of extractable substances obtained in SFE (7.5%) is higher than that obtained by hydrodistillation (3.1%) and SFE is faster than hydrodistillation method.

Orthogonal array design for the optimization of supercritical fluid extraction of baicalin from roots of Scutellaria baicalensis Georgi

Supercritical fluid was used to extract baicalin from the roots of Scutellaria baicalensis Georgi. An orthogonal array design (OAD), OA(9)(3(4)), was employed as a chemometric method for the optimization of the supercritical fluid extraction of baicalin from the herbal medicine. Four parameters, namely, modifiers, temperature and pressure of supercritical fluid, and the dynamic extraction time, were studied and optimized by a three-level OAD in which the interactions between the parameters were neglected. Determinations of the extracts were performed by high-performance liquid chromatography. The effects of parameters were studied using analysis of variance. The results showed that selection of the modifier was the main factor in attaining higher yields of baicalin. While the other three factors had some effect on the extraction of the compound, the effect was much less than that of the modifiers. 1,2-Propanediol-modified supercritical fluid was more effective than 95% ethanol-modified supercritical carbon dioxide or methanol-modified supercritical carbon dioxide for the extraction of baicalin from the solid matrix. Finally, experimental conditions were proposed which can provide the highest extraction yield with respect to the considered factors.

Comparison of essential oils of clove buds extracted with supercritical carbon dioxide and other three traditional extraction methods

Supercritical fluid extraction (SFE) of essential oil from clove buds with CO 2 was explored. The effect of different parameters, such as temperature (30 °C, 40 °C, 50 °C), pressure(10 MPa, 20 MPa, 30 MPa) and particle size (three degree index), on the extraction yield and the content of eugenol in extracts was investigated using three-level orthogonal array design. The experimental results show that the temperature has the largest effect on the eugenol content of the extracts, and particle size has the maximum effect on the oil yield. The essential oil of 19.56% yield, in which the maximum content of eugenol in extracts is 58.77%, can be extracted from clove buds at pressure of 10 MPa and temperature of 50 °C. Essential oil of clove buds obtained by SFE, hydrodistillation, steam distillation and Soxhlet extraction were further analyzed by gas chromatography/mass spectrometric detection to compare the extraction methods. Twenty three compounds in the clove oils have been identified, showing that the composition of the clove oil extracted by different methods is mostly similar, whereas relative concentration of the identified compounds is apparently different. General characteristics of the clove oils obtained by different methods were further compared, and SFE is considered as the optimum process among the four processes for obtaining clove oil with high quality.

Orthogonal Array Design for the Optimization of Supercritical Carbon Dioxide Extraction of Different Metals from a Solid Matrix with Cyanex 301 as a Ligand

In this study, different metal cations such as Ag+, Pd2+, Mn2+, In3+, Au3+, and Bi3+ were removed from a solid matrix using supercritical CO2 containing cyanex 301 as a ligand. When the solvating power of supercritical CO2 is combined with the metal ion complexing power of an organic ligand, a clean alternative to conventional liquid−liquid and liquid−solid extraction is obtained. An orthogonal array design (OAD), OA9 (34), was employed as a chemometric method for the optimization of the supercritical fluid extraction (SFE) of metal cations from a solid matrix. Four parameters, namely, the pressure and temperature of the supercritical fluid, the dynamic extraction time, and the volume of modifier, were studied and optimized by a three-level OAD in which the interactions between the parameters were temporarily neglected. To optimize the SFE condition for each cation, nine experiments were performed in random order. Determinations of the extracts were performed by atomic absorption spectroscopy. The effects of parameters were studied using analysis of variance (ANOVA). The results showed that Ag+, Pd2+, Mn2+, In3+, Au3+, and Bi3+ could be effectively extracted from the solid matrix by using supercritical fluid extraction and cyanex 301 as a chelating agent. Finally, the experimental conditions providing the highest extraction yield inside the experimental domain considered were proposed.

Orthogonal Array Design for Optimizing the Capillary Zone Electrophoretic Analysis of Heterocyclic Amines

Orthogonal array design (OAD) has been applied to the optimization of the capillary zone electrophoretic (CZE) analysis of heterocyclic amines (HCAs), carcinogenic and mutagenic compounds that are found in cooked foods. The factors affecting separation efficiency, such as the pH of the buffer solution, organic modifier and buffer concentrations, the applied potential, and the operating temperature, are studied in two steps under OAD. In the first experiment, each variable is tested at two levels using an OA16 (2(15)) matrix to determine the most important factors and the interactions between them. Based on the results of the first step, the second experiment is implemented according to a three-level OAD with an OA9 (3(4)) matrix, in which more exact values for the important variables are chosen. Finally, the determined optimum conditions for the CZE analysis of the 12 HCAs are applied and evaluated.

Orthogonal array design as a chemometric method for the optimization of analytical procedures. Part 5. Three-level design and its application in microwave dissolution of biological samples.

The theory and methodology of a three-level orthogonal array design as a chemometric method for the optimization of analytical procedures were developed. In the theoretical section, firstly, the matrix of a three-level orthogonal array design is described and orthogonality is proved by a quadratic regression model. Next, the assignment of experiments in a three-level orthogonal array design and the use of the triangular table associated with the corresponding orthogonal array matrix are illustrated, followed by the data analysis strategy, in which significance of the different factor effects is quantitatively evaluated by the analysis of variance (ANOVA) technique and the percentage contribution method. Then, a quadratic regression equation representing the response surface is established to estimate each factor that has a significant influence. Finally, on the basis of the quadratic regression equation established, the derivative algorithm is used to find the optimum value for each variable considered. In the application section, microwave dissolution for the determination of selenium in biological samples by hydride generation atomic absorption spectrometry is employed, as a practical example, to demonstrate the application of the proposed three-level orthogonal array design in analytical chemistry.