Papers by Keyword: HPLC

Abstract: Pancreatic lipase plays an important role in converting triglyceride into long-chain fatty acids and glycerol, then becomes a therapeutic target for obesity treatment. Quercetin and chrysin are able to inhibit pancreatic lipase, which is potentially developed for obesity treatment. This study aimed to identify quercetin and chrysin derived from the methanol extract of raja and kepok banana peels using High Performance Liquid Chromatography (HPLC) and Liquid Chromatography Mass Spectrometer (LC-MS) for the development of obesity treatment. Raja and kepok banana peels were purchased from a fruit seller in Klaten City. Raja and kepok banana peels were extracted using the maceration method with 80% (v/v) methanol solvent. Quercetin and chrysin compounds were identified using HPLC and LC-MS at the Integrated Laboratory UNS and Universitas Diponegoro, respectively. Quercetin concentration was calculated using linear regression of diluted standard quercetin. The quercetin concentration in the raja peel extract was 0.338 mg/dL but was not detected in the kepok banana peel extract. The peak of chrysin in raja and kepok banana peel extract was not detected. LC-MS analysis identified chrysin in raja banana peel extract. In conclusion, raja banana peel extract is a potential source of quercetin and chrysin for alternative natural lipase inhibitors for obesity treatment. Further research is required carry out extraction using other solvents, isolate and purify quercetin and chrysin from raja banana peel extract, which will be used for in vitro and in vivo studies.

Abstract: The Catharanthus roseus plant was extracted and converted to nanoparticles in this work. The Soxhlet method extracted alkaloid compounds from the plant Catharanthus roseus and converted them to the nanoscale. Chitosan polymer was used as a linking material and converted to Chitosan nanoparticles using Sodium TriPolyPhosphate (STPP). The extracted alkaloids were linked with Chitosan nanoparticles CSNPs by maleic anhydride to get the final product (CSNPs- Linker- alkaloids). The synthesized (CSNPs- Linker- alkaloids) was characterized using SEM spectroscopy UV–Vis., Zeta Potential, and HPLC High-Performance Liquid Chromatography. Scanning electron microscope (SEM) analysis shows that the Chitosan nanoparticles (CSNPs) have small dimensions with regular spherical and nanotube shapes of a diameter range of (49 - 70) nm. The final product (CSNPs- Linker- alkaloids) has two shapes (spherical particles and tubes) in nano dimensions and is close to each other compared to normal Chitosan. The absorption peaks for Chitosan (CS), Chitosan nanoparticles (CSNPs), Chitosan nanoparticles (CSNPs), and maleic anhydride revealed that converting Chitosan to Chitosan nanoparticles and mixing it with the plant extract, led to an increase in the absorption value and wavelength range. Also, the appearance of two peaks at 222 nm and 402 nm nano instead of the peak of Chitosan at 289.9 nm. Zeta Potential results of CSNPs- Linker- alkaloids showed that the extract of the nano-alkaloids bound to chitosan nanoparticles carries a positive charge of 54.4 mV. This surface charge is essential in maintaining the colloidal solution's stability in its natural form without changing. High-Performance Liquid Chromatography (HPLC) was used to estimate qualitative and quantitative plants extracted from Catharanthus roseus. Quantitative HPLC results show that Catharanthus roseus contains a good and acceptable concentration of Vinblastine, Vincristine, Vinorelbine, Vincamine, and Vintafolide (66.75, 242.91, 0.7, 83.77, 42.34) ppm respectively. The qualitative results show a good match for the influential groups of pure standard vincristine and alcoholic extract and dry powder of the Catharanthus roseus plant. The successful synthesis of nanoparticles from the Catharanthus roseus plant can be used in biosensors and biomedical applications.

Abstract: This study aims to determine the para-phenylenediamine (PPD) in hair dyes by High-Performance Liquid Chromatography (HPLC). In the presented study, ten hair dye samples were collected from local markets in El-Bieda - Libya. A rapid, simple and reliable method is developed and validated for the determination of PPD in hair dyes samples using 50% methanol solution as solvent. The method was validated over a wide linear range of 5 – 25 µg/mL with correlation coefficients being consistently greater than 0.997. The LOD and LOQ were 1.21 µg/ ml and 3.67 µg/ ml, respectively. Relative standard deviation (% R.S.D.) ranged between 0.07 and 1.15 %. The minimum PPD level was observed in Beauty Touch (Blonde) sample (0.0855 % w/w), while Jourin sense Cosmetics (Black Blue) sample showed the highest PPD content (2.2526 % w/w). The HPLC measurments indicated that the results of PPD concentrations in Black colour samples were in the range of 0.3705 % - 2.2526 % w/w. Whereas its concentrations in anthor colour samples were in the range of 0.0855 % - 0.5936 % w/w. The level of PPD in Black colour samples were higher than other colour samples. The PPD content in all the samples analyzed in this study are well below the allowable limits set by the US Food and Drugs Administration.

Abstract: The extensive use of pesticides in agricultur has raised toxicity level in environment because of their mutagenic and carcinogenic activity. A sensitive technique is needed to develop for the detection of pesticides to get high sensitivity and selectivity in complex matrices. Modified Stober‘s method was used for the synthesis of pure SiO₂ particles and grafted by linoleic acid. Grafted SiO₂ were examined for its capability as a sorbent for removal and preconcentration of four organochlorine pesticides i.e. endrin, dieldrin, aldrin and DDT. The particles of SiO₂ undergo hydrophobic interaction with linoleic acid by grafting. Both pure SiO₂ and linoleic acid grafted SiO₂ particles were characterized by SEM, FTIR and XRD. FTIR confirmed the grafting of SiO₂ with linoleic acid. XRD and SEM results showed monodispersed and spherical SiO₂ particles. The evaluation of grafted SiO₂ was carried out by spiking organochlorine pesticides in drinking water. The grafted SiO₂ particles could be used as a sorbent in solid phase extraction followed by high performance liquid chromatography with reverse phase C18 column with aqueous acetonitrile as a mobile phase with ultraviolet detector at 224 nm. The percent recoveries for aldrin, dieldin, endrin and DDT were 81, 52, 60 and 91%, respectively.

Abstract: The present study reports the analytical approaches for characterization of teeth whitening gels based on natural extracts of fruits and medicinal plant. High performance liquid chromatography (HPLC) with UV detection were used for identification and quantification of (oxalic, citric, tartaric, malic, succinic and fumaric acids), flavonoids (catechin, epicatechin, rutin and quercetin) and phenolic acids (vanillic acid, p-coumaric acid, ferullic acid) from studied gels samples used for teeth whitening. The organic acids were used as active agent with action in tooth discoloration and stain removal. Organic acids were separated through a Carbosep Coregel 87H3 column at 35°C and detection at 214 nm. The mobile phase was the sulphuric acid 0.005 M solution. The total quantity of organic acids of these gel samples was determined. The action of flavonoids have controlled dental caries and inhibited plaque formation. Separation of flavonoids and phenolic acids was carried out on Lichrosorb RP-C18 column at 40 oC and detection at 290 nm. The mobile phase was a mixture of methanol and solution 0.1% formic acid in a gradient elution. The flavonoids, catechin, epicatechin, rutin and quercetin and phenolic acids, vanillic acid, p-coumaric acid, ferullic acid, were determined quantitative in the teeth whitening gels on natural extracts of fruits and medicinal plant.

Abstract: Gallium (Ga) is a critical element for the electronic industry, however, its long-term supply is not assured. Thus, the recovery of Ga from industrial wastewaters is important. Selective sorption is a recommended technology for the recovery of Ga from industrial wastewaters, however, selective sorbents are elusive. Desferrioxamine B (DFOB), a hydroxomate siderophore that is known to be highly selective towards Fe³⁺, is tested for its ability to complex Ga. This study demonstrated that DFOB forms 1:1 complex with Ga and the maximum Q_e-Ga is 124.4 mg of Ga complexed per g of DFOB. Further, the complexation mechanism of Ga³⁺ and Fe³⁺ with DFOB is similar, as indicated by NMR, suggesting that the selectivity of DFOB towards Fe³⁺ will be extended to Ga³⁺ as well. Thus, DFOB seems to be a suitable candidate for the sorption of Ga from industrial wastewaters.

Abstract: Simulated Moving Bed (SMB) chromatographic processes for the enantiomers separation of the drug verapamil were evaluated through stepwise modeling approach. Predictions of the model were compared to the dispersive equilibrium model in the simulation of continuous separation process and validated with data taken for both compounds in a SMB experimental set-up. An inverse problem tool was associated to the chromatographic columns aiming at their characterization through the global mass transfer parameters using only the experimental residence times of each enantiomer. According to the study conducted, the proposed approach was shown to be a tool with a good potential to predict the chromatographic behavior of a sample in a test pulse, as well as the simulation of separation of a compound in SMB equipment despite minor discrepancies presented in the first work cycles of the SMB. Moreover, the approach can be easily implemented and applied in the analysis of the process.

Abstract: In this study, a rapid and selective method has been developed to determine PENG residues in waste penicillium chrysogenum by using SPE cleanup strategy followed by HPLC. Furthermore, some parameters which influenced the extraction efficiency including extraction mode, solvent and time, while washing solution and eluting solution for SPE were systematically investigated. It should be noted that the extraction process was carried out in a single step by mixing the extraction solvent acetonitrile: formic acid in aqueous solution and chrysogenum samples under ultrasound. The SPE procedure was conducted using Oasis HLB as the clean up cartridge, n-hexane as washing solution, and mixture of acetonitrile and methanol as eluting solution. Under the optimized conditions, the linear of PENG are in the range of 0.1-2000 μg/mL, with the correlation was R²>0.99. In addition, the recoveries of PENG in these samples at three fortification levels of 800-1800mg/kg were 74.98% to 113.47% are obtained, respectively. Moreover, a limits of detection (0.006 mg/kg) and quantification (0.02 mg/kg) could be achieved.

Abstract: The etched stainless steel powder was prepared and explored as sorbent material for solid-phase extraction coupled with high-performance liquid chromatography (HPLC) for determination of trace polycyclic aromatic hydrocarbons (PAHs) in environmental matrices. The etched stainless steel powder was shown to be promising for solid-phase extraction of PAHs in environmental samples with subsequent HPLC separation and UV detection. This paper explored different factors that affected the adsorption efficiency of etched stainless steel powder, including the etched time of stainless steel powder, the mass of sorbent, and the volume of water sample, and so on. In the optimum conditions, nine kinds of PAHs, including trace naphthalene, acenaphthylene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzanthracene and benzopyrene, were extracted by etched stainless powder and the extraction efficiency is satisfactory.

Abstract: Thispaper studies the method of detecting antibiotic trimethoprim (TMP) in theenvironment water, sewage and tap water with high performance liquidchromatography –diode array detector (HPLC-DAD). The chromatographic conditionis confirmed that: the stationary phase is ODS, the mobile phase is acetonitrileand methanoic acid aqueous solution of 0.1%（12:88）, the flow rate is 1.5min·L^-1; theinjection volume is 5μL，the chromatographic column temperature is 25°C,DAD detection wavelength is 272nm. The experiment result shows that, the linearlydependent coefficient of external standard curve is 0.996, the detection limitis 0.017 mg·L^-1, adding standard recovery ranges from 92.6-140.6 ％.