scholarly journals Structural Characterisation of Deposit Layer during Milk Protein Microfiltration by Means of In-Situ MRI and Compositional Analysis

Membranes ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 59 ◽  
Author(s):  
Roland Schopf ◽  
Nicolas Schork ◽  
Estelle Amling ◽  
Hermann Nirschl ◽  
Gisela Guthausen ◽  
...  
Keyword(s):  
Protein Fraction ◽  
Milk Protein ◽  
Structural Information ◽  
Reversed Phase ◽  
Hollow Fibre ◽  
Layer Formation ◽  
Protein Fractionation ◽  
Rp Hplc ◽  
Deposit Layer

Milk protein fractionation by microfiltration membranes is an established but still growing field in dairy technology. Even under cross-flow conditions, this filtration process is impaired by the formation of a deposit by the retained protein fraction, mainly casein micelles. Due to deposition formation and consequently increased overall filtration resistance, the mass flow of the smaller whey protein fraction declines within the first few minutes of filtration. Currently, there are only a handful of analytical techniques available for the direct observation of deposit formation with opaque feed media and membranes. Here, we report on the ongoing development of a non-invasive and non-destructive method based on magnetic resonance imaging (MRI), and its application to characterise deposit layer formation during milk protein fractionation in ceramic hollow fibre membranes as a function of filtration pressure and temperature, temporally and spatially resolved. In addition, the chemical composition of the deposit was analysed by reversed phase high pressure liquid chromatography (RP-HPLC). We correlate the structural information gained by in-situ MRI with the protein amount and composition of the deposit layer obtained by RP-HPLC. We show that the combination of in-situ MRI and chemical analysis by RP-HPLC has the potential to allow for a better scientific understanding of the pressure and temperature dependence of deposit layer formation.

scholarly journals In situ measurement of deposit layer formation during skim milk filtration by MRI

2019 ◽  
Vol 57 (9) ◽  
pp. 738-748 ◽  
Author(s):  
Nicolas Schork ◽  
Sebastian Schuhmann ◽  
Hermann Nirschl ◽  
Gisela Guthausen
Keyword(s):  
Skim Milk ◽  
In Situ Measurement ◽  
Layer Formation ◽  
Deposit Layer

scholarly journals Comparative Assessment of Tubular Ceramic, Spiral Wound, and Hollow Fiber Membrane Microfiltration Module Systems for Milk Protein Fractionation

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 692
Author(s):  
Roland Schopf ◽  
Florian Schmidt ◽  
Johanna Linner ◽  
Ulrich Kulozik
Keyword(s):  
Hollow Fiber ◽  
Milk Protein ◽  
Hollow Fiber Membrane ◽  
Comparative Assessment ◽  
Transmission Factor ◽  
Transmembrane Pressure ◽  
Protein Fractionation ◽  
Flow Conditions ◽  
Local Pressure ◽  
Spiral Wound

The fractionation efficiency of hollow fiber membranes (HFM) for milk protein fractionation was compared to ceramic tubular membranes (CTM) and spiral wound membranes (SWM). HFM combine the features of high membrane packing density of SWM and the more defined flow conditions and better control of membrane fouling in the open flow channel cross-sections of CTM. The aim was to comparatively analyze the effect of variations in local pressure and flow conditions while using single industrially sized standard modules with similar dimensions and module footprints (module diameter and length). The comparative assessment with varied transmembrane pressure was first applied for a constant feed volume flow rate of 20 m3 h−1 and, secondly, with the same axial pressure drop along the modules of 1.3 bar m−1, similar to commonly applied crossflow velocity and wall shear stress conditions at the industrial level. Flux, transmission factor of proteins (whey proteins and serum caseins), and specific protein mass flow per area membrane and per volume of module installed were determined as the evaluation criteria. The casein-to-whey protein ratios were calculated as a measure for protein fractionation effect. Results obtained show that HFM, which so far are under-represented as standard module types in industrial dairy applications, appear to be a competitive alternative to SWM and CTM for milk protein fractionation.

scholarly journals Development and validation of RP-HPLC method for estimation of brexpiprazole in its bulk and tablet dosage form using Quality by Design approach

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Amol S. Jagdale ◽  
Nilesh S. Pendbhaje ◽  
Rupali V. Nirmal ◽  
Poonam M. Bachhav ◽  
Dayandeo B. Sumbre
Keyword(s):  
Flow Rate ◽  
High Performance ◽  
Reversed Phase ◽  
Hplc Method ◽  
Control Analysis ◽  
Uv Detector ◽  
Mobile Phase Flow Rate ◽  
Rp Hplc ◽  
Quality By Design Approach ◽  
Bulk Drug

Abstract Background A new, sensitive, suitable, clear, accurate, and robust reversed-phase high-performance liquid chromatography (RP-HPLC) method for the determination of brexpiprazole in bulk drug and tablet formulation was developed and validated in this research. Surface methodology was used to optimize the data, with a three-level Box-Behnken design. Methanol concentration in the mobile phase, flow rate, and pH were chosen as the three variables. The separation was performed using an HPLC method with a UV detector and Openlab EZchrom program, as well as a Water spherisorb C18 column (100 mm × 4.6; 5m). Acetonitrile was pumped at a flow rate of 1.0 mL/min with a 10 mM phosphate buffer balanced to a pH of 2.50.05 by diluted OPA (65:35% v/v) and detected at 216 nm. Result The developed RP-HPLC method yielded a suitable retention time for brexpiprazole of 4.22 min, which was optimized using the Design Expert-12 software. The linearity of the established method was verified with a correlation coefficient (r2) of 0.999 over the concentration range of 5.05–75.75 g/mL. For API and formulation, the percent assay was 99.46% and 100.91%, respectively. The percentage RSD for the method’s precision was found to be less than 2.0%. The percentage recoveries were discovered to be between 99.38 and 101.07%. 0.64 μg/mL and 1.95 μg/mL were found to be the LOD and LOQ, respectively. Conclusion The developed and validated RP-HPLC system takes less time and can be used in the industry for routine quality control/analysis of bulk drug and marketed brexpiprazole products. Graphical abstract

scholarly journals Daptomycin: A Novel Macrocyclic Antibiotic as a Chiral Selector in an Organic Polymer Monolithic Capillary for the Enantioselective Analysis of a Set of Pharmaceuticals

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3527
Author(s):  
Ali Fouad ◽  
Adel A. Marzouk ◽  
Montaser Sh. A. Shaykoon ◽  
Samy M. Ibrahim ◽  
Sobhy M. El-Adl ◽  
...  
Keyword(s):  
Glycidyl Methacrylate ◽  
Chiral Stationary Phase ◽  
Reversed Phase ◽  
Chiral Selector ◽  
Antifungal Drugs ◽  
Organic Polymer ◽  
Rp Hplc ◽  
Macrocyclic Antibiotic ◽  
Adrenergic Blockers ◽  
H1 Blockers

Daptomycin, a macrocyclic antibiotic, is here used as a new chiral selector in preparation of chiral stationary phase (CSP) in a recently prepared polymer monolithic capillary. The latter is prepared using the copolymerization of the monomers glycidyl methacrylate (GMA) and ethylene glycol dimethacrylate (EGDMA) in the presence of daptomycin in water. Under reversed phase conditions (RP), the prepared capillaries were tested for the enantioselective nanoliquid chromatographic separation of fifty of the racemic drugs of different pharmacological groups, such as adrenergic blockers, H1-blockers, NSAIDs, antifungal drugs, and others. Baseline separation was attained for many drugs under RP-HPLC. Daptomycin expands the horizon of chiral selectors in HPLC.

Investigation of Phenolic Content in Five Different Pine Barks Species Grown in Turkey by HPLC-UV and LC–MS

2021 ◽  
Author(s):  
Mehmet Emin Şeker ◽  
Ali Çelik ◽  
Kenan Dost ◽  
Ayşegül Erdoğan
Keyword(s):  
Sample Preparation ◽  
Orthophosphoric Acid ◽  
Phenolic Content ◽  
Reversed Phase ◽  
Uv Detector ◽  
Epicatechin Gallate ◽  
Rp Hplc ◽  
Phenolic Constituents ◽  
Preparation Step ◽  
Very High

Abstract Investigation of phenolic content from different pine bark species grown in Turkey was performed using a reversed-phase high pressure liquid chromatography with ultraviolet (RP-HPLC-UV) method. All phenolic constituents were separated in <26 min on reversed-phase C18 column with gradient mobile phase that consists of orthophosphoric acid, methanol and acetonitrile. Detections were made on an UV detector at 280 nm and at a flow rate of 1 mL/min. Samples were prepared according to Masqueller’s conventional sample preparation method with slight modifications. To avoid the reduction in extraction efficiency the sample preparation step was carried out under argon atmosphere. The linearity of the method was between 0.9994 and 0.9999. The detection limits for the five phenolic constituents ranged from 0122 to 0.324 mg/L. Catechin and taxifolin were found in all pine barks at a concentration of 0.065 ± 0.002–1.454 ± 0.004 and 0.015 ± 0.001–23.164 ± 0.322 mg/g, respectively. Epicatechin was determined in four pine barks between 0.027 ± 0.001 and 0.076 ± 0.002 mg/g, ferulic acid in two pine barks between 0.010 ± 0.001 and 0.022 ± 0.001 mg/g and epicatechin gallate in only one of the pine barks at 0.025 ± 0.001 mg/g. Finally, the total amount of phenolic compounds and antioxidant capacities of the pine barks were found to be very high.

SELECTION OF COLUMN AND OPERATING CONDITIONS FOR REVERSED-PHASE HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY OF PROTEINS IN CANADIAN WHEAT

1985 ◽  
Vol 65 (2) ◽  
pp. 285-298 ◽  
Author(s):  
J. E. KRUGER ◽  
B. A. MARCHYLO
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Storage Proteins ◽  
Sodium Dodecyl ◽  
Reversed Phase ◽  
Operating Conditions ◽  
Protein Patterns ◽  
Optimal Separation ◽  
Rp Hplc

Chromatographic conditions were optimized and three commercially available columns were evaluated for separation of alcohol-soluble storage proteins of Neepawa wheat using reversed-phase high-performance liquid chromatography (RP-HPLC). Optimal separation was achieved using an extracting solution of 50% 1-propanol, 1% acetic acid, and 4% dithiothreitol and an HPLC elution time of 105 min at a flow rate of 1.0 mL/min. HPLC columns evaluated (SynChropak RP-P, Ultrapore RPSC and Aquapore RP-300) varied in selectivity and resolution. The column providing the greatest versatility was Aquapore RP-300 available in cartridge form. Sodium dodecyl sulfate gradient-gel electrophoresis analysis of protein peaks resolved by RP-HPLC indicated that many of the eluted peaks contained more than one protein species. Chromatographic protein patterns obtained for Neepawa wheat grown at different locations and in different years were qualitatively the same.Key words: Protein, high-performance liquid chromatography, wheat

Standardisation of Artemisia annua using Reversed Phase High Performance Liquid Chromatography (RP-HPLC).

2010 ◽  
Vol 2 (7) ◽  
pp. 142-147
Author(s):  
O. Amos Abolaji ◽  
M. Ubana Eteng ◽  
E. Patrick Ebong ◽  
Andi Brisibe ◽  
Ahmed Shakil ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Artemisia Annua ◽  
Reversed Phase ◽  
Rp Hplc
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