The US-SPE-HPLC–UV extraction procedure. Display omitted
•We synthesis molecularly imprinted nanoparticles with different porogen solvent.•Selective extraction of celecoxib using molecularly ...imprinted nanoparticles-ultrasound assisted was developed.•Extraction optimization using five variables at five levels were applied.•This method had highly selective compare with other technique.•Ultrasound shows considerable advantage on the solid phase extraction.
In this work molecular imprinted nanoparticles (MINPs) was synthesized and applied for ultrasonic assisted solid phase extraction of celecoxib (CEL) from human plasma sample following its combination by HPLC–UV. The MINPs were prepared in a non-covalent approach using methacrylic acid as monomer, CEL as template, ethylene glycol dimethacrylate as cross-linker, and 2,2-azobisisobutyronitrile (AIBN) as the initiator of polymerization. pH, volume of rinsing and eluent solvent and amount of sorbent influence on response were investigated using factorial experimental design, while optimum point was achieved and set as 250mg sorbent, pH 7.0, 1.5mL washing solvent and 2mL eluent by analysis of results according to design expert (DX) software. At above specified conditions, CEL in human plasma with complicated matrices with acceptable high recoveries (96%) and RSD% lower than 10% was quantified and estimated.
The proposed MISPE-HPLC–UV method has linear responses among peak area and concentrations of CEL in the range of 0.2–2000μgL−1, with regression coefficient of 0.98. The limit of detection (LOD) and quantification (LOQ) based on three and ten times of the noise of HPLC peaks correspond to blank solution were 0.08 and 0.18μgL−1, respectively.
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•Phthalic acid as switchable-hydrophilicity solvent for the extraction of sildenafil.•No sample cooling is required for the solidification of phthalic acid.•The analytical protocol is ...rapid using environmentally friendly solvents.
Herein, a green liquid phase microextraction protocol using phthalic acid as switchable hydrophilicity solvent (SHS) is reported for the quantification of sildenafil in authentic human urine. The analyte was extracted onto phthalic acid solid particles which were produced through acidification of the sample. Its solidification was accomplished at ambient conditions without sample cooling. The determination of the sildenafil was carried out using high performance liquid chromatography-ultraviolet detection (HPLC-UV). The microextraction parameters that affect the extraction efficiency of the drug (i.e. SHS type and its concentration, acid type and concentration, extraction time, filter type) have been studied. The optimized analytical protocol involved the mixing of 300 μL of phthalate solution (0.75 M) with 600 μL of sample, followed by the addition of 50 μL of concentrated H3PO4. The produced solid was collected using membrane syringe filter (0.45 μm) and was finally dissolved in 500 μL of CH3OH. Method validation data showed determination coefficient ≥ 0.99 for the linear range of 50 – 2000 ng/mL. The limit of detection (LOD) and the lower limit of quantitation (LLOQ) were 30 and 100 ng/mL, respectively. The accuracy (expressed as % recovery) of the method ranged between 88.0 – 108.9 % while the precision (expressed as % RSD) was less than 17.8 % in all cases. The robustness of the microextraction procedure and the instrumental method were investigated using Plackett-Burman experimental designs. The applicability of the method was demonstrated by analyzing both spiked and authentic human urine samples after oral administration of drug-containing pharmaceutical formulation. The developed protocol offers cost-efficiency, handling simplicity, and high throughput. Its green character was evaluated using Green Analytical Procedure Index and Blue Applicability Grade Index.
Although the occurrence of glandular trichomes is frequently reported for aerial vegetative organs, many questions still remain opened about the presence of such trichomes in underground systems. ...Here, we present, for the first time, a comparative study concerning the structure, ultrastructure and chemical aspects of both, the aerial and underground glandular trichomes of two different Chrysolaena species, C. obovata and C. platensis. Glandular trichomes (GTs) were examined using LM, SEM, and TEM and also analyzed by GC–MS and HPLC coupled to UV/DAD and HR-ESI-MS (HPLC–UV–MS). In both aerial (leaf and bud) and underground (rhizophore) organs, the GTs are multicellular, biseriate and formed by five pairs of cells: a pair of support cells, a pair of basal cells, and three pairs of secreting cells. These secreting cells have, at the beginning of secretory process, abundance of smooth ER. The same classes of secondary metabolites are biosynthesized and stored in both aerial and underground GTs of C. platensis and C. obovata. These GTs from aerial and underground organs have similar cellular and sub-cellular anatomy, however the belowground trichomes show a higher diversity of compounds when compared to those from the leaves. We also demonstrate by means of HPLC–UV–DAD that the sesquiterpene lactones are located inside the trichomes and that hirsutinolides are not artifacts.
•New dispersive solid phase extraction method.•Surfactant-coated titanium-based nanomagnetic sorbent.•Efficient and fast sample preparation method.•Appropriate pre-concentration factor and method ...detection limit.
Herein, a new extraction method employing a surfactant-coated titanium-based nanomagnetic sorbent for the effective extraction of bisphenol A (BPA) from various water samples was developed. Initially, the titanium-based nanomagnetic particles (Fe3O4/SiO2/TiO2 NPs) were successfully synthesized and subsequently characterized by Transmission Electron Microscopy and Fourier-transform infrared spectrometry. Two cationic surfactants were then incorporated into the particles to form a new sorbent for enhancing the extraction of BPA through micelle formation. Once the analyte was extracted, it was desorbed from the sorbent and quantified by high performance liquid chromatography with ultra violet detection (HPLC-UV). Various factors affecting the extraction and desorption of the analyte were investigated in detail and the optimum conditions established. Under these established conditions, the calibration curve was linear over the concentration range of 1–500ng/mL. The limit of detection was determined to be 0.5ng/mL based on a signal-to-noise ratio (S/N)=3. To test the extraction efficiency, the method was applied to various real water samples that were spiked. The average recoveries obtained from the spiked samples ranged between 92–105% with relative standard deviations of 3.2–7.8%. Finally, the approach was determined to be effective for BPA environmental analysis.
•Determination of curcumin in Curcuma longa extract and emulsion using HPLC method.•System suitability studies were performed.•Stress degradation studies of curcumin in emulsion formulation.
A ...stability-indicating HPLC–UV method for the determination of curcumin in Curcuma longa extract and emulsion was developed. The system suitability parameters, theoretical plates (N), tailing factor (T), capacity factor (K′), height equivalent of a theoretical plate (H) and resolution (Rs) were calculated. Stress degradation studies (acid, base, oxidation, heat and UV light) of curcumin were performed in emulsion. It was found that N>6500, T<1.1, K′ was 2.68–3.75, HETP about 37 and Rs was 1.8. The method was linear from 2 to 200μg/mL with a correlation coefficient of 0.9998. The intra-day precision and accuracy for curcumin were ⩽0.87% and ⩽2.0%, while the inter-day precision and accuracy values were ⩽2.1% and ⩽−1.92. Curcumin degraded in emulsion under acid, alkali and UV light. In conclusion, the stability-indicating method could be employed to determine curcumin in bulk and emulsions.
Polyphenols are phytochemicals that exist in grapes and are beneficial to human health. In this study, resveratrol, oxyresveratrol, and piceatannol in wine were extracted by deep eutectic solvent ...dispersive liquid–liquid microextraction (DES‐DLLME), and a method was established for quantifying these polyphenols by high‐performance liquid chromatography‐UV/Vis (HPLC‐UV/Vis). Several parameters pertaining to sample extraction, clean‐up, and concentration were optimized and verified with central composite design (CCD) using Design Expert 11. The optimized sample preparation parameters are as follows: the DES extraction solvent, tributylmethylammonium chloride/decanoic acid (1:3 M ratio); basic solvent, 1.3 mL of 5% potassium bicarbonate; volume of acetic anhydride, 250 μL; derivatization time, 5 min; dispersive solvent, methanol; ratio of extraction and dispersive solvents, 1:5.5; and salt, 1.0 g. Chromatographic separation by HPLC/UV–Vis was performed on an ACME C18 (4.6 mm id × 150 mm length, 5 μm particle size) column in gradient elution mode using water and 70% methanol. Under the established extraction and HPLC‐UV conditions, the limit of detection (LOD) and limit of quantitation (LOQ) of the three analytes in spiked samples ranged from 1.69 to 2.53 μg/L and 5.64 to 8.42 μg/L, respectively. Recovery studies were performed in low, medium, and high concentration ranges to establish a calibration curve, and the accuracy and precision in the working range were 95.1–108.0% and 1.3–6.7 RSD%, respectively. The calibration curves for quantitative analysis were obtained in the concentration ranges 5.6–56.4, 8.3–82.6, and 8.4–84.2 μg/L, with correlation coefficients (r2) ranging from 0.9947 to 0.9967. The proposed method was applied to the determination of polyphenols in wine samples.
Response surface plots.
In the present work, a magnetic metal-organic framework composite (Fe3O4@TGA@TMU-6) was synthesized and used as an adsorbent for magnetic solid-phase extraction (MSPE) of some organophosphorus ...pesticides (phosalone, chlorpyrifos and, profenofos) in rice and environmental water samples. Extraction, separation and determination of the analytes were performed by MSPE-HPLC-UV. Due to the large surface area and unique porous structure of the metal-organic frameworks (MOFs) as well as π-π and hydrophobic interactions between the analytes and the MOF ligands, the prepared sorbents showed a high affinity towards the target analytes. The affecting parameters on the extraction efficiency, including type and volume of eluent, pH, amount of MFC, extraction time, salt effect and desorption time were investigated and optimized. Under optimum conditions, calibration curves were found to be linear in the range of 7.5–75 μg L−1, 10–100 μg L−1, and 10–150 μg L−1 for phosalone, chlorpyrifos, and profenofos in water samples, respectively. The LODs (based on S/N = 3) were 0.5, 1 and 0.5 μg L−1 for phosalone, chlorpyrifos, and profenofos in water samples, respectively.
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➢Fe3O4@TGA@TMU-6 was synthesized by ultrasound assisted layer-by-layer strategy.➢It was used for magnetic solid-phase extraction of some organophosphorus pesticides (OPPs).➢Separation and determination of the analytes was performed by HPLC-UV.➢They exhibit high specific surface areas and high extraction efficiency for interest OPPs.➢The method was used for successful analysis of three OPPs in rice samples.
Regorafenib has been approved for the treatment of colorectal cancer, gastrointestinal stromal tumor and hepatocellular carcinoma. High-performance liquid chromatography (HPLC) was developed and ...validated for determination of regorafenib in xenograft tumors. After protein precipitation with acetonitrile, regorafenib were separated using gradient elution (C18 Ultrabase column). Quantification was performed at 262 nm. Calibration curves were linear over the range 48.8-50000 ng/ml. The assay was applied to the determination of the drug in the tumor of nude mice receiving regorafenib 50 mg orally, and could be useful for therapeutic drug monitoring of regorafenib in routine clinical practice.
•A method to quantify ciprofloxacin in plasma by HPLC–UV.•Simple protein precipitation from serum with good recovery.•Validated method with acceptable reproducibility, precision, accuracy and ...stability.•Useful to quantify the concentration of ciprofloxacin in patients with Peripheral Arterial Disease.•Study will establish if an appropriate dosage regimen is being given to such patients.
A rapid and sensitive HPLC–UV method for the determination of ciprofloxacin in human plasma is described. Protein precipitation with acetonitrile was used to separate the drug from plasma protein. An ACE® 5 C18 column (250mm×4.6mm, 5μm) with an isocratic mobile phase consisting of phosphate buffer (pH 2.7) and acetonitrile (77:23, v/v) was used for separation. The UV detector was set at 277nm. The method was validated in the linear range of 0.05–8μg/ml with acceptable inter- and intra-assay precision, accuracy and stability. The method is simple and rapid and can be used to quantify this widely used antibiotic in the plasma of patients suffering from Peripheral Arterial Disease.
Herein, a microextraction method was reported based on the liquid-solid phase transition of benzoic acid to quantify two statins, namely lovastatin and simvastatin in authentic human urine. The ...principle of the method is based on the phase transition of benzoic acid by altering the pH of the sample solution enabling efficient dispersion and phase separation in one step. Due to the moderate melting point of benzoic acid, its solidification is performed at ambient temperature without the need for sample cooling. Various experimental parameters that affect the performance of the analytes (i.e. extractant type and its concentration, acid type and concentration, and sample volume) have been examined and optimized. The method was validated based on the total error concept. For this purpose, accuracy profiles were constructed in the concentration range of 100–5000 ng mL−1 while β-expectation tolerance intervals fell within ±15% demonstrating that 95% of future results will not exceed the defined bias limits. The intra-day and inter-day method precision was less than 4.7% and 4.3% for both analytes, while the limit of detection was 15 ng mL−1 for both analytes. It was also proved that the usage of benzoic acid is advantageous in minimizing the potential inter-conversion of the analytes during the acidification step of the extraction procedure. The green potential of the proposed analytical scheme was examined based on Green Analytical Procedure index. The proposed sample pretreatment technique proved to be a valuable tool offering selectivity and rapidness. The developed method was used for the analysis of real human urine obtained after the administration of statin-based pharmaceutical formulations.
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•Benzoic acid was used as switchable-hydrophilicity solvent for the extraction of statins•The solidification of benzoic acid is performed without the need of sample cooling•The analytical scheme is simple and cost-effective using environmentally friendly solvents
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