The liquid chromatography of cholesterol esters

1991 ◽  
Vol 56 (4) ◽  
pp. 796-808 ◽  
Author(s):  
Ladislav Svoboda ◽  
Alena Krejčová
Keyword(s):  
Liquid Chromatography ◽  
Silica Gel ◽  
Mobile Phase ◽  
High Performance ◽  
Reversed Phase ◽  
Cholesterol Esters ◽  
Octadecyl Silica Gel ◽  
Unsaturated Carboxylic Acids ◽  
Retention Characteristics ◽  
Phase Systems

The retention characteristics were found for cholesterol and 19 of its esters with saturated and unsaturated carboxylic acids containing 1 to 22 carbon atoms using high performance liquid chromatography in the normal and reversed-phase systems. HPLC on silica gel in a mobile phase consisting of heptane and 2-propanol or ethyl acetate is especially suitable for analysis of the esters of the lower acids, while chromatography on an octadecyl silica gel sorbent in a water-tetrahydrofuran or acetonitrile-dichlormethane mobile phase can bee successfully used for the separation of esters with acids containing 10–22 carbon atoms, that can differ in the presence of double bonds in the acyl or through cis-trans isomerism.

Separation and Determination of Some Aromatic Sulfones by Reversed-Phase High-Performance Liquid Chromatography

1994 ◽  
Vol 59 (3) ◽  
pp. 569-574 ◽  
Author(s):  
Josef Královský ◽  
Marta Kalhousová ◽  
Petr Šlosar
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Mobile Phase ◽  
High Performance ◽  
Reversed Phase ◽  
Uv Spectra ◽  
Optimum Conditions ◽  
Linear Calibration ◽  
Technical Grade

The reversed-phase high-performance liquid chromatography of some selected, industrially important aromatic sulfones has been investigated. The chromatographic behaviour of three groups of aromatic sulfones has been studied. The optimum conditions of separation and UV spectra of the sulfones and some of their hydroxy and benzyloxy derivatives are presented. The dependences of capacity factors vs methanol content in mobile phase are mentioned. The results obtained have been applied to the quantitative analysis of different technical-grade samples and isomer mixtures. For all the separation methods mentioned the concentration ranges of linear calibration curves have been determined.

4-Nitrophenol in 4-nitrophenyl phosphate, a substrate for alkaline phosphatase, as measured by paired-ion high-performance liquid chromatography.

1977 ◽  
Vol 23 (12) ◽  
pp. 2288-2291 ◽  
Author(s):  
P H Culbreth ◽  
I W Duncan ◽  
C A Burtis
Keyword(s):  
Alkaline Phosphatase ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Flow Rate ◽  
Mobile Phase ◽  
High Performance ◽  
Reversed Phase ◽  
Nitrophenyl Phosphate ◽  
Phase Column ◽  
Reversed Phase Column

Abstract We used paired-ion high-performance liquid chromatography to determine the 4-nitrophenol content of 4-nitrophenyl phosphate, a substrate for alkaline phosphatase analysis. This was done on a reversed-phase column with a mobile phase of methanol/water, 45/55 by vol, containing 3 ml of tetrabutylammonium phosphate reagent per 200 ml of solvent. At a flow rate of 1 ml/min, 4-nitrophenol was eluted at 9 min and monitored at 404 nm; 4-nitrophenyl phosphate was eluted at 5 min and could be monitored at 311 nm. Samples of 4-nitrophenyl phosphate obtained from several sources contained 0.3 to 7.8 mole of 4-nitrophenol per mole of 4-nitrophenyl phosphate.

scholarly journals Determination of (–)-Quinine and (+)-Quinidine by Liquid Chromatography with Diode-Laser Polarimetric Detection

1999 ◽  
Vol 82 (6) ◽  
pp. 1308-1315 ◽  
Author(s):  
Francisco García Sánchez ◽  
Aurora Navas Díaz ◽  
Angeles García Pareja ◽  
Germán Cabrera Montiel
Keyword(s):  
Liquid Chromatography ◽  
Diode Laser ◽  
Mobile Phase ◽  
High Performance ◽  
Dynamic Range ◽  
Reversed Phase ◽  
Rabbit Serum ◽  
In Series ◽  
Phase Column

Abstract High-performance liquid chromatography using a combination of photometric, fluorimetric, and diode-laser polarimetric detectors in series for the determination of (+)-quinidine and (–)-quinine was investigated. An RP-8 reversed-phase column and methanol-water (80 + 20, v/v) with 0.2% triethylamine as mobile phase at a flow rate of 1 mL/min were used. A dynamic range of 0-200 μg for (+)-quinidine and (+)-quinine was established, with detection limits of 17.0 and 16.7 μg, respectively. An application of this method in spiked rabbit serum was developed.

scholarly journals Development and validation of reversed phase high performance liquid chromatography (RP-HPLC) for quantification of captopril in rabbit plasma

2020 ◽  
Author(s):  
Muhammad Fawad Rasool ◽  
Umbreen Fatima Qureshi ◽  
Nazar Muhammad Ranjha ◽  
Imran Imran ◽  
Mouqadus Un Nisa ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Mobile Phase ◽  
High Performance ◽  
Limit Of Detection ◽  
Reversed Phase ◽  
Rabbit Plasma ◽  
Rp Hplc ◽  
Relative Standard

AbstractTh accurate rapid, simple and selective reversed phase high performance liquid chromatography (RP-HPLC) has been established and validated for the determination of captopril (CAP). Chromatographic separation was accomplished using prepacked ODSI C18 column (250 mm × 4.6 mm with 5 μm particle size) in isocratic mode, with mobile phase consisting of water: acetonitrile (60:40 v/v), pH adjusted to 2.5 by using 85% orthophosphoric acid at a flow rate of 1 mL/min and UV detection was performed at 203 nm. RP-HPLC method used for the analysis of CAP in mobile phase and rabbit plasma was established and validated as per ICH-guidelines. It was carried out on a well-defined chromatographic peak of CAP was established with a retention time of 4.9 min and tailing factor of 1.871. The liquid–liquid extraction method was used for extraction of CAP from the plasma. Excellent linearity (R2 = 0.999) was shown over range 3.125–100 µg/mL with mean percentage recoveries ranges from 97 to 100.6%. Parameters of precision and accuracy of the developed method meet the established criteria. Intra and inter-day precision (% relative standard deviation) study was also performed which was less than 2% which indicate good reproducibility of the method. The limit of detection (LOD) and quantification for the CAP in plasma were 3.10 and 9.13 ng/mL respectively. The method was suitably validated and successfully applied to the determination of CAP in rabbit plasma samples.

scholarly journals Correlation between retention and C-18 silica gel surface coverage in reversed-phase liquid chromatography

2000 ◽  
Vol 65 (11) ◽  
pp. 811-818
Author(s):  
Marijana Acanski ◽  
Slobodan Petrovic ◽  
Vjera Pejanovic ◽  
Julijana Petrovic
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Carbon Content ◽  
Silica Gel ◽  
High Performance ◽  
Surface Coverage ◽  
Reversed Phase ◽  
Reversed Phase Liquid Chromatography ◽  
Retention Behaviour ◽  
Phase Liquid

The effect of C-18 silica gel surface coverage on the retention behaviour of some estrone derivatives in reversed phase high performance liquid chromatography has been studied. Two commercial columns with different C-18 coverage, Spherisorb ODS-1(8 % carbon content) and Li Chrosorb RP-18(22% carbon content), using methanol-water as the eluent, were used.

DEVELOPMENT AND VALIDATION OF THE REVERSED-PHASE HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY METHOD FOR THE ESTIMATION OF GUAIFENESIN IN METHOCARBAMOL API AND ITS PHARMACEUTICAL DOSAGE FORMS

2018 ◽  
Vol 11 (5) ◽  
pp. 401
Author(s):  
Mannem Durga Babu ◽  
Kesana Surendrababu
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Mobile Phase ◽  
High Performance ◽  
Reversed Phase ◽  
Dosage Forms ◽  
Solution Stability ◽  
Chromatography Method ◽  
Pharmaceutical Dosage Forms ◽  
Liquid Chromatography Method

Objective: The objective of the study was to develop and validate a novel, specific, precise, and simple reversed-phase high-performance liquid chromatography method for the estimation of guaifenesin present in methocarbamol API and its pharmaceutical dosage forms. Methods: The baseline separation for methocarbamol and guaifenesin was achieved by utilizing a Inertsil ODS C18 (250 mm × 4.6 mm) 5 μm column particle size and an isocratic elution method. The mobile phase contains a mixture of water and acetonitrile in the ratio of 70:30 v/v, respectively. The flow rate of the mobile phase was 1.0 mL/min with a column temperature of 25°C and detection wavelength at 272 nm. The method was validated for a limit of detection (LOD), limit of quantification (LOQ), linearity, accuracy, and reproducibility with the help of the exhibit and simulated samples. Results: The LOD for guaifenesin was 0.62 μg/mL. The LOQ for guaifenesin was 1.87 μg/mL. The correlation coefficient obtained for impurity was >0.99. The recovery was obtained for impurity was 106.56% at 50%, 95.20% at 100%, and 100.45% at 150%. In tablet analysis, we can found 0.26% (<0.5%). Conclusion: The developed method was validated as per the ICH guidelines with respect to specificity, precision, linearity, accuracy, LOD and quantification, ruggedness, robustness, and solution stability.

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