High pH mobile phase effects on silica-based reversed-phase high-performance liquid chromatographic columns

1995 ◽  
Vol 691 (1-2) ◽  
pp. 3-19 ◽  
Author(s):  
J.J. Kirkland ◽  
M.A. van Straten ◽  
H.A. Claessens
Author(s):  
Grishma H Patel ◽  
Shreya D Adeshra ◽  
Dhananjay B Meshram

A Novel, selective, accurate and rapid Reversed Phase High Performance Liquid Chromatographic (RPHPLC) method for the analysis of Efonidipine Hydrochloride Ethanolate and Telmisartan in binary mixture has been developed and validated. The chromatographic system consisted of a Phenomenex Kinetex ® 5µ C18 Size: 150 * 4.6mm column and the separation was achieved by using ambient temperature with a mobile phase containing mobile Phase Acetonitrile:25mM Phosphate Buffer pH 4.9 (45:55). The samples were monitored at 253 nm for detection at a flow rate of 1.0 mL/min and the retention time was about 7.77 and 4.10 mins for Efonidipine Hydrochloride Ehanolate and Telmisartan respectively. The calibration curve was linear over the concentration range 5-30 and 10-60 ?g/mL for Efonidipine Hydrochloride Ehanolate and Telmisartan respectively. The proposed method is accurate in the range of 99.75% - 100.10% recovery and precise (%RSD of intraday variation and % RSD of inter day variation were found to be within the acceptance criteria). Therefore, this method can be used as a more convenient and efficient option for the analysis of Efonidipine Hydrochloride Ehanolate and Telmisartan in Quality control laboratory.


2017 ◽  
Vol 1 (2) ◽  
pp. 1-8
Author(s):  
Milena Cristina Ribeiro Souza Magalhães ◽  
Alisson Samuel Portes Caldeira ◽  
Hanna De Sousa Rocha Almeida ◽  
Sílvia Ligório Fialho ◽  
Armando Da Silva Cunha Junior

A reversed-phase high-performance liquid chromatographic (HPLC) method was developed and validated for the determination of encapsulation efficiency of zidovudine in nanoparticules. The method was carried out in isocratic mode using 0.040M sodium acetate: methanol: acetonitrile: glacial acetic acid (880:100:20:2) as mobile phase, a C8 column at 25ºC and UV detection at 240 nm. The method was linear (r2 ˃ 0.99) over the range of 25.0-150.0 μg/mL, precise (RSD ˂ 5%), accurate (recovery = 100.5%), robust and selective. The validated HPLC-UV method can be successfully applied to determine the rate of zidovudine in nanoparticules.


1988 ◽  
Vol 34 (4) ◽  
pp. 724-729 ◽  
Author(s):  
M Hariharan ◽  
T VanNoord ◽  
J F Greden

Abstract We describe a rapid, sensitive method for the routine simultaneous determination of nicotine and cotinine in 1 mL of plasma. Extraction in 10-mL screw-capped Teflon tubes with methylene chloride after deproteinization with trichloroacetic acid eliminated emulsion formation. The extract, after evaporation and reconstitution in 30 microL of mobile phase, is injected into a reversed-phase C-18 ion-pair column of an isocratic high-performance liquid-chromatographic unit. Absorbance is monitored at 256 nm. The mobile phase is a citrate-phosphate (30 mmol each per liter) buffer mixture containing 50 mL of acetonitrile and 1 mmol of sodium heptanesulfonate per liter. 2-Phenylimidazole is the internal standard. The detection limit is 1 microgram/L for nicotine and 3 micrograms/L for cotinine. The standard curve is linear from 0 to 700 micrograms/L for both compounds. The average CV for nicotine in the concentration range 0-100 micrograms/L is 6.5%, and that for cotinine in the concentration range 50-700 micrograms/L is 4%.


1986 ◽  
Vol 32 (1) ◽  
pp. 197-200 ◽  
Author(s):  
M Bliss ◽  
M Mayersohn

Abstract We describe a "high-performance" liquid-chromatographic assay for quantifying cefamandole in biological fluids from patients with renal impairment. Serum samples are deproteinized with acetonitrile, then extracted with dichloromethane; dialysis-fluid samples are injected directly; urine samples are diluted appropriately before injection onto the reversed-phase column. The mobile phase is a methanol/aqueous solution (31/69 by vol) containing 500 microL of phosphoric acid, 20 mmol of sodium sulfate, and 200 microL of triethylamine per liter, the mixture being adjusted to pH 6.0 with NaOH. Retention time for cefamandole is 12 min. Its peak is well resolved in highly contaminated samples from renally impaired subjects. The assay's selectivity, reproducibility (within-day and between-day CVs less than 8% in all three sample fluids), and sensitivity--0.5 mg/L in serum, 1.0 mg/L in dialysis fluid, and 5.0 mg/L in urine--make it applicable to pharmacokinetic studies.


2009 ◽  
Vol 6 (2) ◽  
pp. 489-494 ◽  
Author(s):  
B. Prasanna Kumar Reddy ◽  
Y. Ramanjaneya Reddy ◽  
D. Ramachandran

A simple, sensitive and precise high performance liquid chromatographic method for the analysis of pantoprazole sodium and lansoprazole has been developed, validated and used for the determination of compounds in commercial pharmaceutical products. The compounds were well separated an isocratically on a C18column [Inertsil C18, 5μ, 150 mm x 4.6 mm] utilizing a mobile phase consisting of acetonitrile: phosphate buffer (60:40, v/v, pH 7.0) at a flow rate of 1.0 mL/min with UV detection at 230 nm. The retention time of pantoprazole sodium and lansoprazole was found to be 2.017 min and 2.538. The procedure was validated for linearity (Correlation coefficient=0.999). The study showed that reversed-phase liquid chromatography is sensitive and selective for the determination of pantoprazole sodium and lansoprazole using single mobile phase.


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