Analysis of whey proteins during ripening of Afuega'l Pitu cheese by reversed phase HPLC Análisis por RP-HPLC de las proteínas del suero del queso Afuega'l Pitu durante la maduración

1997 ◽  
Vol 3 (6) ◽  
pp. 445-449 ◽  
Author(s):  
D. González de Llano ◽  
G. Santa-María
Keyword(s):  
Protein Content ◽  
Whey Protein ◽  
High Performance ◽  
Whey Proteins ◽  
Correlation Coefficients ◽  
Reversed Phase ◽  
Soluble Form ◽  
Soluble Nitrogen ◽  
Ripening Time ◽  
Rp Hplc

Evolution of the whey proteins fractions and proteolysis indices from 12 batches of the artisan cheese Afuega'l Pitu variety were studied by reversed phase high performance liquid chro matography (RP-HPLC) over the ripening period. The correlation coefficients between the whey protein contents and ripening time were very low, indicating that the whey protein content did not change as the cheese aged. However, soluble nitrogen content and the percentage of total nitrogen in the soluble form showed correlation coefficients higher than 0.9 with increasing ripening time. Analysis of variance showed significant differences ( p < 0.05) between dairies for most of the variables with the exception of β-lactoglobulin A and bovine serum albumin. These variables were also significantly different between the two manufacture zones. Conversely, no significant differences ( p < 0.05) were observed between the two varieties of cheese, red and white, for whey protein content or for proteolysis indices.

scholarly journals Whey Proteins Characterization, Free Amino Acids Profile and Antimicrobial Study of Some Dairy Drinks based on Milk Serum

2020 ◽  
Author(s):  
Doina Prodan ◽  
Miuța Filip ◽  
Mihaela Vlassa ◽  
Marioara Moldovan ◽  
Rahela Carpa ◽  
...  
Keyword(s):  
Amino Acids ◽  
Free Amino Acids ◽  
Free Amino ◽  
High Performance ◽  
Whey Proteins ◽  
Reversed Phase ◽  
Bacterial Strains ◽  
Isoleucine Leucine ◽  
Milk Serum ◽  
Rp Hplc

The aim of this study was characterization of some dairy drinks based on Milk Serum regarding major whey proteins (WP) and free amino acids (FAAs) using reversed phase high performance liquid chromatographic (RP-HPLC) methods. The studied WP, -lactalbumin (-La), bovine serum albumin (BSA), -lactoglobulin A (-Lg A) and -lactoglobulin B (-Lg B) were separated on Aeris XB-C18 column at 214 nm detection. The RP-HPLC method was validated by selectivity, linearity (R2 &ge;0.99), sensitivity (LOQ, 1.35&ndash;10.08 &micro;g mL&minus;1), accuracy (recovery 96.79-103.07%) and precision (% RSD &le; 4.13%). The total studied WP in studied dairy drinks varied between 1.42 and 3.047 g·L-1. The chromatographic profile of FAAs (aspartic acid, glutamic acid, serine, histidine, arginine, glycine, threonine, alanine, tyrosine, cysteine, tryptophan, methionine, valine, phenylalanine, isoleucine, leucine and lysine) was determined in lyophilized concentrate of Milk Serum by RP-HPLC using pre-column derivatization reaction with orthophthalaldehyde (OPA). The total studied FAAs in studied samples varied between 1.103 and 1.119 mg·g-1. Moreover, the Milk Serum showed bacteriostatic activity against two bacterial strains Escherichia coli and Staphylococcus aureus. The obtained results confirm that dairy drinks based on the Milk Serum constitutes a valuable sources of bioactive components with benefits for human healthy nutrition.

Development of RP-HPLC Method for Estimation of Valsartan and Hydrochlorothiazide in Tablets

2013 ◽  
Vol 6 (4) ◽  
pp. 2240-2244
Author(s):  
Cylma Menezes ◽  
Vishal M ◽  
Shyamkumar B ◽  
Reema N
Keyword(s):  
High Performance ◽  
Dynamic Range ◽  
Correlation Coefficients ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Hplc Method ◽  
Simultaneous Estimation ◽  
Rp Hplc ◽  
Validation Parameters ◽  
Liquid Chromatographic

A simple, efficient and reproducible reversed phase high performance liquid chromatographic (RP-HPLC) method was developed and validated for the simultaneous estimation of valsartan and hydrochlorothiazide in bulk and in tablets. A column having 250 x 4.6 mm i.d. (Kromasil C18) in isocratic mode with mobile phase containing 50 mM potassium dihydrogen o-phosphate buffer (triethylamine 0.2%), (pH 3.7 adjusted with o-phosphoric acid): acetonitrile (56:44 v/v) was used. The flow rate was 1.0 ml/min and effluent was monitored at 232 nm.  The retention time of valsartan and hydrochlorothiazide was 10.15 and 3.78 min respectively. All calibration curves showed good linear correlation coefficients within the tested limits (r2 > 0.9995). The linearity dynamic range was found to be 20-150 µg/ml and 5-45 µg/ml for valsartan and hydrochlorothiazide respectively. Percentage recoveries for valsartan and Hydrochlorothiazide were 100.45 % and 98.75 % respectively. All the analytical validation parameters were determined and found in the limit as per the International Conference on Harmonization (ICH) guidelines which indicates the validity of the method. The developed method was found to be accurate, precise and robust for the simultaneous estimation of valsartan and hydrochlorothiazide in bulk and in tablets.

Simultaneous Determination of L-Ascorbic Acid and L-Ascorbylpalmitate Using RP-HPLC Method

2013 ◽  
Vol 716 ◽  
pp. 465-469
Author(s):  
Ye Lin Tian ◽  
Jun Kai Wang ◽  
Ping Sheng Leng ◽  
Yun Liu
Keyword(s):  
Ascorbic Acid ◽  
Simultaneous Determination ◽  
Methyl Palmitate ◽  
High Performance ◽  
Correlation Coefficients ◽  
Reversed Phase ◽  
Hplc Method ◽  
Enzymatic Transesterification ◽  
Rp Hplc

A rapid reversed phase highperformance liquid chromatography (RP-HPLC) method was developed for the simultaneous analysis of L-ascorbic acid and L-ascorbylpalmitate (AP). The chromatography was performed on a SSI model 2300-525 high performance liquid chromatographequipped with anAlltechApollo C18 column at 30 oC.The mobile phase was acetonitrile-water (90:10,v/v) with the flow rate of 1.0 mL/min. UV detection wavelength was 250 nm. This method permits the simultaneous determination of ascorbic acid and AP in the synthesis of AP transesterified with methyl palmitate and ascorbic acid. The detection limit of ascorbic acid and AP was 0.07μg/mL and 0.12μg/mL, respectively. The recovery was 90.59 ± 3.04% for ascorbic acid and 101.3 ± 4.81% for AP. The linearity range for ascorbic acid and AP was in the range of 0.1 - 0.7 mg/mL and 0.4 - 4.0 mg/mL, respectively. Correlation coefficients (R2) were 0.9910 for ascorbic acid and 0.9986 for AP. The proposed method could be used for routine quality control of AP synthesis with methyl palmitate and ascorbic acidby enzymatic transesterification.

scholarly journals Controlling the correctness of retention parameters variations in reversed phase HPLC using recurrent relations

2021 ◽  
Vol 25 (2) ◽  
pp. 117-125
Author(s):  
Igor G. Zenkevich ◽  
◽  
Abdennour Derouiche ◽  
Darja A. Nikitina ◽  
Tatiana A. Kornilova ◽  
...  
Keyword(s):  
High Performance ◽  
Hydrate Formation ◽  
Correlation Coefficients ◽  
Reversed Phase ◽  
Data Sets ◽  
Data Set ◽  
Simple Method ◽  
Rp Hplc ◽  
Recurrent Relations ◽  
Retention Parameters

Recurrent approximation of analytes’ net retention times (tR) in reversed phase high performance liquid chromatography (RP HPLC) at different contents of organic constitu­ent in the eluent (C) is recommended as a method of revealing the reversible hydrate for­ma­tion. The criterion of that are the deviations of the dependences tR(С + DС) = atR(С) + b (*) from linearity, where DС is the constant increment of concentration variations; in our case DС = 5%. However, such deviations are rather small and, hence their measuring requires high robustness of the equipment involved. Besides hydrate formation, there are additional reasons for deviations, namely discrepancies between the real and the selected flows of the eluent. Compa­ring tR values obtained for the same analytes using the same chromatogra­phic column at the same conditions, but with different HPLC instruments using the systems methanol – water as the eluent confirms that tR values of one data set are equal only to approx. 76-98% tR values of another data set. Therefore, the eluent flow in the second case exceeds that in the first regime at the same pro­por­tion. The simple method for revealing such flow deviations is proposed. It is based on the recurrent approximation of tR = f(C) data sets for any compounds forming no hydrates in RP HPLC conditions (chlorobenzene was selected). The absence of the influ­en­ce of any distorted factors is confirmed with values of correlation coefficients for re­cur­rent depen­dencies (*) exceeding 0.999.

scholarly journals Separation of Cyclic Dipeptides (Diketopiperazines) from Their Corresponding Linear Dipeptides by RP-HPLC and Method Validation

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Mareike Perzborn ◽  
Christoph Syldatk ◽  
Jens Rudat
Keyword(s):  
Amino Acids ◽  
High Performance ◽  
Correlation Coefficients ◽  
Reversed Phase ◽  
Short Term ◽  
Freeze Thaw ◽  
Rp Hplc ◽  
Relative Standard ◽  
Detection And Separation

Simple, rapid, sensitive, precise, and accurate methods for detection and separation of seven diketopiperazines (DKPs), cyclo(Gly-Gly), cyclo(dl-Ala-dl-Ala), cyclo(l-Asp-l-Phe), cyclo(l-Asp-l-Asp), cyclo(Gly-l-Phe), cyclo(l-Pro-l-Tyr), and cyclo(l-Arg-l-Arg), from their corresponding linear dipeptides and related amino acids l-Phe and l-Tyr by reversed-phase high-performance liquid chromatography (RP-HPLC) were established. Moreover, for the racemic DKP cyclo(dl-Ala-dl-Ala) and dipeptide dl-Ala-dl-Ala, separation of the diastereomers was achieved. All methods can be performed within 15 min. For all DKPs, dipeptides, and amino acids, linear ranges with correlation coefficients R2 greater than 0.998 were determined. Lowest limits of detection were found to be between 0.05 and 10 nmol per 10 μL injection, depending on the substance. For all tested substances intrarun and interrun precision ranged from 0.5 to 4.7% and 0.7 to 9.9% relative standard deviation, and accuracy was between −4.2 and 8.1% relative error. Short-term and freeze-thaw stabilities were 93% or greater for all substances. Recovery rate after heat treatment was determined to be at least 97%. These methods will be useful for quantitative determination of DKPs and their potential biodegradation products: dipeptides and amino acids

Distinction of Different Heat-Treated Skim Milk by RP-HPLC of their Whey Proteins

2012 ◽  
Vol 468-471 ◽  
pp. 1482-1485
Author(s):  
Xin Xin Zhu ◽  
Jing Hua Yu ◽  
Zheng Zhao ◽  
Xiao Hui Liu ◽  
Qiu Qin Li
Keyword(s):  
High Performance ◽  
Heating Temperature ◽  
Whey Proteins ◽  
Bovine Milk ◽  
Skim Milk ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Rp Hplc ◽  
Heated Milk ◽  
Heat Treated

RP-HPLC (reversed-phase high-performance liquid chromatographic) was used for simultaneous qualitative and quantitative analysis of whey proteins of laboratory heat-treated bovine milk. Four whey proteins, including BSA, α-La, β-LgB and β-LgA, could be distinctively separated. The results showed that stability of whey proteins in heated milk varied greatly with different heating temperature. The BSA exhibited the worst heat-tolerance: about all of it was lost after 85°C for 5min and in contrast the α-La was the strongest. That β-LgB and β-LgA have similar trends: the denaturation of β-LgB and β-LgA was both no more than 10% as the skim milk was heated at 55°C or 65°C, but all of them was lost after heated to 95°C for 5min.

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

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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