Optimization of peptide separations in reversed-phase HPLC: Isocratic versus gradient elution

1987 ◽  
Vol 24 (1) ◽  
pp. 565-572 ◽  
Author(s):  
C. T. Mant ◽  
T. W. Lorne Burke ◽  
R. S. Hodges
Keyword(s):  
Gradient Elution ◽  
Reversed Phase ◽  
Reversed Phase Hplc ◽  
Peptide Separations

Gradient elution in reversed-phase HPLC-separation of macromolecules

1983 ◽  
Vol 55 (14) ◽  
pp. 1412A-1430A ◽  
Author(s):  
L. R. Snyder ◽  
M. A. Stadalius ◽  
M. A. Quarry
Keyword(s):  
Gradient Elution ◽  
Reversed Phase ◽  
Reversed Phase Hplc ◽  
Hplc Separation

Allantoin as a marker of oxidative stress in human erythrocytes

2008 ◽  
Vol 46 (9) ◽  
Author(s):  
Roman Kand'ár ◽  
Pavla Žáková
Keyword(s):  
Oxidative Stress ◽  
Renal Failure ◽  
Uric Acid ◽  
Chronic Renal Failure ◽  
Gradient Elution ◽  
Reversed Phase ◽  
Control Group ◽  
Uric Acid Concentration ◽  
Reversed Phase Hplc

Abstract: Uric acid is the final product of purine metabolism in humans. It was determined that this compound has important antioxidative properties and it may be oxidized to allantoin by various reactive oxygen species. Therefore, the measurement of allantoin may be useful for the determination of oxidative stress in humans.: We measured allantoin and uric acid in human plasma and erythrocytes obtained from patients with chronic renal failure before hemodialysis (n=30) and blood donors (n=30). We used a method based on selective isolation of allantoin from deproteinized plasma and erythrocyte lysate samples on AG 1-X8 resin and its derivatization to glyoxylate-2, 4-dinitrophenylhydrazone. Separation of glyoxylate-2, 4-dinitrophenylhydrazone from interfering substances was achieved on reversed phase HPLC with gradient elution and UV/VIS detection at 360 nm. Uric acid was determined by reversed phase HPLC with UV/VIS detection at 292 nm.: We found significant differences in allantoin and uric acid concentration between the patients with chronic renal failure and the control group both in plasma (20.5±6.5 μmol/L and 323.9±62.9 μmol/L vs. 2.1±1.1 μmol/L and 270.1±62.3 μmol/L, p<0.05) and erythrocytes [82.8±39.1 nmol/g hemoglobin (Hb) and 110.7±28.8 nmol/g Hb vs. 20.1±6.1 nmol/g Hb and 82.1±23.7 nmol/g Hb, p<0.05].: Significant higher levels of allantoin in both plasma and erythrocytes of patients with chronic renal failure indicate that allantoin may be used as a good marker of oxidative stress.Clin Chem Lab Med 2008;46:1270–4.

Application of Reversed-Phase HPLC in Some Critical Peptide Separations

1984 ◽  
Vol 22 (6) ◽  
pp. 234-238 ◽  
Author(s):  
P. S. L. Janssen ◽  
J. W. van Nispen ◽  
R. L. A. E. Hamelinck ◽  
P. A. T. A. Melgers ◽  
B. C. Goverde
Keyword(s):  
Reversed Phase ◽  
Reversed Phase Hplc ◽  
Peptide Separations

scholarly journals DETERMINATION OF ANTHOCYANINS OF FRUITS OF SOME PLANTS OF THE GENUS RIBES BY REVERSED-PHASE HPLC AND HYDROPHILIC INTERACTION CHROMATOGRAPHY (HILIC)

2020 ◽  
pp. 81-88
Author(s):  
Viktor Ivanovich Deineka ◽  
Elena Yur'yevna Oleinits ◽  
Aleksandr Alekseyevich Pavlov ◽  
Andrey Yur'yevich Mikheev ◽  
Ol'ga Vladimirovna Shelepova ◽  
...  
Keyword(s):  
Stationary Phases ◽  
Gradient Elution ◽  
Botanical Garden ◽  
Reversed Phase ◽  
Hydrophilic Interaction Chromatography ◽  
Coumaric Acid ◽  
Reversed Phase Hplc ◽  
Hydrophilic Interaction ◽  
Cinnamic Acids

The anthocyanin composition of some species of gooseberries with colored fruits was studied in comparison with anthocyanins of currant fruits from the collection of the Tsitsin Main Botanical garden. In fruits of currants Ribes nigrum var. sibiricum E. Wolf, R. nigrum L., R. americanum Mill., as well as in dark-colored fruits R. aureum Pursh., 3-glucosides and 3-rutinosides of cyanidin and delphinidin were found as major components in species-dependent ratios. It was found that in the fruits of gooseberry species Ribes oxyacanthoides L., Ribes missouriensis (Nutt.) Coville & Britton, Ribes rusticum Jancz. and Ribes cynosbati (L.) Mill. and in the fruits of one of the currants (R. alpinum L.) there is practically no biosynthesis of delphinidin derivatives, and 3-glucoside and 3-rutinoside of cyanidin are detected. Meanwhile, the biosynthesis of acylated by substituted cinnamic acids (mainly – p-coumaric acid) anthocyanins were found in the fruits of Ribes oxyacanthoides and Ribes cynosbati (about 10%), Ribes rusticum (about 20%). The inheritance of characteristic for the fruit of some species of gooseberry biosynthesis of acylated mainly p-coumaric acid, was installed in the fruits of jostaberry - Ribes x nidigrolaria Rud. Bauer & A. Bauer (about 10%). The species composition of anthocyanins was established using traditional reversed-phase HPLC in gradient elution mode using diode-array and mass spectrometric detection options. In addition, a method for the separation of anthocyanins of the same objects in the isocratic mode under hydrophilic interaction chromatography on diol stationary phases, allowing the use of simpler equipment. The variants of sample preparation of extract samples for the subsequent HPLC determination of anthocyanins by two different methods to avoid the appearance of artifacts are proposed.

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