scholarly journals A Validated Ultrasound-Assisted Extraction Coupled with SPE-HPLC-DAD for the Determination of Flavonoids in By-Products of Plant Origin: An Application Study for the Valorization of the Walnut Septum Membrane

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6418
Author(s):  
Natasa P. Kalogiouri ◽  
Victoria F. Samanidou
Keyword(s):  
Functional Properties ◽  
High Performance ◽  
Solid Phase ◽  
Good Precision ◽  
Bioactive Constituents ◽  
Ultrasound Assisted Extraction ◽  
Relative Standard ◽  
Ultrasound Assisted ◽  
Flavonoid Fraction

Walnut byproducts have been shown to exert functional properties, but the literature on their bioactive content is still scarce. Among walnut byproducts, walnut septum is a dry ligneous diaphragm tissue that divides the two halves of the kernel, exhibiting nutritional and medicinal properties. These functional properties are owing to its flavonoid content, and in order to explore the flavonoid fraction, an ultrasound-assisted (UAE) protocol was combined with solid phase extraction (SPE) and coupled to high-performance liquid chromatography with diode array detection (HPLC-DAD) for the determination of flavonoids in Greek walnut septa membranes belonging to Chandler, Vina, and Franquette varieties. The proposed UAE-SPE-HPLC-DAD method was validated and the relative standard deviations (RSD%) of the within-day and between-day assays were lower than 6.2 and 8.5, respectively, showing good precision, and high accuracy ranging from 90.8 (apigenin) to 97.5% (catechin) for within-day assay, and from 88.5 (myricetin) to 96.2% (catechin) for between-day assay. Overall, seven flavonoids were determined (catechin, rutin, myricetin, luteolin, quercetin, apigenin, and kaempferol) suggesting that the walnut septum is a rich source of bioactive constituents. The quantification results were further processed using ANOVA analysis to examine if there are statistically significant differences between the concentration of each flavonoid and the variety of the walnut septum.

scholarly journals Reversed-Phase High-Performance Liquid Chromatography Determination of Selected Phenolic Acids in Propolis Concentrates in Terms of Standardization For Drug Manufacturing Purposes

2006 ◽  
Vol 89 (2) ◽  
pp. 352-358 ◽  
Author(s):  
Jan Krzek ◽  
Jolanta Kaleta ◽  
Urszula Hubicka ◽  
Aneta Niedzwiedz
Keyword(s):  
Antibacterial Activity ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Solid Phase ◽  
Reversed Phase ◽  
Good Precision ◽  
Relative Standard ◽  
Ferulic Acids

Abstract A reversed-phase high-performance liquid chromatography method with gradient elution was developed for the determination of the caffeic, p-coumaric, and ferulic acids in propolis concentrates. Solid-phase extraction on an RP18 column was applied for preliminary purification, and chromatographic separation was performed on 100 RP18e Lichrospher column of particle size 5 m. The mobile phase was obtained by mixing in appropriate ratios 0.03 mM NaH2PO4, acidified with H3PO4 up to pH 3.0, with acetonitrile to obtain a gradient in the elution process. Spectrophotometric detection was conducted at 320 nm. Under the established conditions, the method featured high sensitivity, good precision, and comparability of results, as proven by method validation and statistical analysis of the obtained results. The limits of detection were 0.315, 0.325, and 0.695 g/mL for caffeic, p-coumaric, and ferulic acids, respectively. The corresponding recovery values were 98.14, 101.05, and 99.42 and the linearity ranges from 1.31 to 99.18 g/mL, 1.52 to 119.16 g/mL, and 2.42 to 184.14 g/mL. The precision of the method was expresed by relative standard deviation values that did not exceed 3. It was also shown that the propolis concentrates under examination had similar antibacterial activity against Staphylococcus aureus ranging from 119.8 to 124.3 g/mL, contrary to model mixtures that showed no antibacterial activity.

Fluoroimmunoassay Based on FITC-Labeled Antibody for the Determination of Estradiol

2014 ◽  
Vol 960-961 ◽  
pp. 3-6
Author(s):  
Long Jun Wang ◽  
Wei Li Xue ◽  
Ling Yun Du
Keyword(s):  
Human Urine ◽  
High Performance ◽  
Solid Phase ◽  
High Sensitivity ◽  
Good Precision ◽  
Experimental Conditions ◽  
Time Saving ◽  
Relevant Variable ◽  
Relative Standard

A new fluorescence immunoassay with high sensitivity, time-saving, good precision and reliablility was proposed for the determination of estradiol (E2) in human urine. The complex of FITC-labeled anti-E2antibody was produced and regarded as a probe in this system. Ninety-six microplate was coated with ovalbumin conjugated E2antigen as solid phase for the immunoassay. The method parameters affecting the determination, such as the concentration of immunoreagents, pH, and other relevant variable conditions upon the immunoassay were studied and optimized systematically. Under the optimal experimental conditions, it was found that the proposed method exhibited high performance with the detection limit of 9.2 pg/mL, and the linear range of determination of 0.01-1000 ng/mL. The recoveries were 93.58-105.82% with the relative standard deviations (RSD) 5.52-7.09%. The proposed method has been used for the determination of E2in human urine with satisfactory results, and may be expected to find wide application in other environmental samples.

QuEChERS with ultrasound-assisted extraction combined with high-performance liquid chromatography for the determination of 16 polycyclic aromatic hydrocarbons in sediment

2021 ◽  
Author(s):  
Ling Wu ◽  
Qiurong He ◽  
Jing Zhang ◽  
Yongxin Li ◽  
Weiqing Yang ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Aromatic Hydrocarbons ◽  
High Performance ◽  
Ultrasound Assisted Extraction ◽  
Sediment Samples ◽  
Assisted Extraction ◽  
Polycyclic Aromatic ◽  
Ultrasound Assisted

Abstract Background Polycyclic aromatic hydrocarbons (PAHs) have attracted worldwide attention due to their carcinogenic, teratogenic and mutagenic effects, environmental persistence and bioaccumulation characteristics. Therefore, the sensitive, reliable and rapid detection of PAHs in sediment is of great importance. Objective To develop a high-performance liquid chromatography (HPLC) with fluorescence and ultraviolet detection after QuEChERS treatment for simultaneous determination of 16 U.S. Environmental Protection Agency priority PAHs in sediment samples. Methods The samples were ultrasonically extracted with acetone and then the supernatant was purified with a modified QuEChERS method. After centrifugation, the supernatant was injected into the HPLC system for analysis. The separation was accomplished on a ZORBAX Eclipse PAH column (150 × 4.6 mm, 3.5 μm) and the column temperature was set at 30 °C. The flow rate of the mobile phase consisting of water and acetonitrile in gradient elution mode was fixed at 0.9 mL/min. Detection was conducted on an ultraviolet detector and a fluorescence detector simultaneously. The qualitative analysis was based on retention time and the quantification was based on standard curves. Results Under the optimal conditions, this method showed good linearities in the range of 10–200 μg/L with correlation coefficients greater than 0.9993. The method had the limits of detection (LODs) ranging from 0.00108 to 0.314 ng/g. The mean recoveries ranged from 78.4 to 117% with the intra-day and inter-day relative standard deviations (RSDs) of 0.592–10.7 and 1.01–13.0%, respectively. The proposed method was successfully applied to the detection of 16 PAHs in sediment samples collected from the Funan River in Chengdu, China with the total contents of 431 to 2143 ng/g·dw. Conclusions The established method is simple, rapid, environment-friendly and cost- effective. It can be applied to the analysis of 16 PAHs in sediment samples. Highlights A method of QuEChERS with ultrasound-assisted extraction combined with HPLC has been established for the analysis of 16 PAHs in sediment samples and the proposed method has been successfully applied to the analysis PAHs in real sediment samples.

scholarly journals Determination of Patulin in Apple Juice: Comparative Evaluation of Four Analytical Methods

2007 ◽  
Vol 90 (1) ◽  
pp. 162-166 ◽  
Author(s):  
David R Katerere ◽  
Sonja Stockenström ◽  
Gabriele Balducci ◽  
Gordon S Shephard
Keyword(s):  
Comparative Evaluation ◽  
High Performance ◽  
Apple Juice ◽  
Solid Phase ◽  
Phase Extraction ◽  
Low Concentrations ◽  
Relative Standard ◽  
Purification Methods ◽  
Union Directive

Abstract The performance of 4 purification methods for the analysis of patulin in apple juice was evaluated by high-performance liquid chromatography (HPLC). Samples were spiked with patulin at 10, 20, 50, 100, and 150 ppb (ng/mL) and extracted by one of 4 methods (3 solid-phase extraction and one liquidliquid extraction), and then analyzed by HPLCUV under the same isocratic conditions. The methods were validated for recovery, linearity, and precision at high and low concentrations. Recoveries were all >70% for spiking range 10-150 ppb. The relative standard deviation for repeatability was found to meet European Union Directive requirements. In addition, all the methods showed baseline separation from hydroxymethylfurfural.

Simultaneous Determination of Four Plant Hormones in Soil by Ultrasound-Assisted Ionic Liquid Based Dispersive Liquid-Liquid Microextraction

2014 ◽  
Vol 675-677 ◽  
pp. 181-184 ◽  
Author(s):  
Gui Qi Huang ◽  
She Ying Dong ◽  
Zhen Yang ◽  
Ting Lin Huang
Keyword(s):  
Ionic Liquid ◽  
Plant Hormones ◽  
High Performance ◽  
Extraction Solvent ◽  
Target Analytes ◽  
Relative Standard ◽  
Ultrasound Assisted ◽  
Dispersive Liquid Liquid Microextraction ◽  
Liquid Microextraction

An ultrasound-assisted ionic liquid based dispersive liquid-liquid microextraction (UA-IL-DLLME) was developed for the determination of four plant hormones (6-benzyladenine (6-BA), kinetin (6-KT), 2, 4-dichlorophenoxy acetic acid (2, 4-D) and uniconazole (UN)) in soil, using high performance liquid chromatography (HPLC)-diode array detection (DAD). Several important parameters including the type and volume of extraction solvent, the volume of disperser solvent, ultrasound time, pH of the solution and salt effect were studied and optimized. Under optimum conditions, the limits of detections (LODs) for the target analytes were in the range of 0.002-0.01 μg g-1. And satisfactory recoveries of the target analytes in the soil samples were 79.3-96.7 %, with relative standard deviations (RSD, n=5) that ranged from 4.3 to 6.7%.

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