Ethyl lactate as an environmentally friendly HPLC mobile-phase modifier in the analysis of acetaminophen, caffeine, and ASA

2013 ◽  
Vol 91 (5) ◽  
pp. 352-356 ◽  
Author(s):  
Michael D. Judge ◽  
Curtis Aab
Keyword(s):  
Acetic Acid ◽  
Mobile Phase ◽  
Environmentally Friendly ◽  
Ethyl Lactate ◽  
Core Shell ◽  
Organic Modifier ◽  
Optimal Conditions ◽  
Mobile Phases ◽  
Hplc Mobile Phase ◽  
Mobile Phase Modifier

Ethyl lactate (EL) has been investigated as an environmentally friendly organic modifier for use in HPLC mobile phases. EL shows significant promise in this regard when used under optimal conditions. In conjunction with a standard C18 column at a temperature of 60 °C, a mobile phase composed of 87% water, 10% EL, and 3% acetic acid is capable of baseline resolution of three standard pharmaceutical analytes (acetaminophen, caffeine, and acetylsalicylic acid) in under three minutes. This same mobile phase was found to be capable of extraction of these same analytes from consumer pain relief tablets with essentially 100% efficiency. Using a core-shell C18 column at 40 °C, similar resolution and run times with these analytes are possible using the same mobile phase but with a reduced EL content of only 2.5%.

Application of Mobile Phases Containing Ionic Liquid for HPLC Analysis of Selected Isoquinoline Alkaloids

2017 ◽  
Vol 100 (6) ◽  
pp. 1652-1659 ◽  
Author(s):  
Anna Petruczynik ◽  
Justyna Misiurek ◽  
Tomasz Tuzimski ◽  
Monika Waksmundzka-Hajnos
Keyword(s):  
Ionic Liquid ◽  
Stationary Phases ◽  
Reversed Phase ◽  
System Efficiency ◽  
Organic Modifier ◽  
Optimal Conditions ◽  
Retention Behavior ◽  
Isoquinoline Alkaloids ◽  
Mobile Phases ◽  
Chemical Groups

Abstract An HPLC procedure on a polar reversed-phase column with mobile phases containing ionic liquid (IL) was developed for the analysis of selected alkaloids from different chemical groups. We aimed to obtain optimal conditions for the separation of alkaloids because widely used silica-based stationary phases exhibit a silanol effect, rendering analysis of basic analytes extremely difficult. Retention, separation selectivity, peak symmetry, and system efficiency were examined in various eluent systems containing different concentrations of IL and acetonitrile. The obtained results revealed substantial influence from the concentrations of IL, the organic modifier, and temperature on the retention behavior of the investigated alkaloids. The most selective and efficient chromatographic systems were applied for the analysis of several alkaloids in a plant extract.

Comparative Study for Selection of the Optimum Mobile Phase for Separation of Caffeine and Paracetamol by Using TLC Chromatographic Method

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Mohammed Gamal ◽  
Ali Turki ◽  
Almonzer Al-Shemari ◽  
Abd Alla Alomari
Keyword(s):  
Acetic Acid ◽  
Literature Review ◽  
Comparative Study ◽  
Ethyl Acetate ◽  
Mobile Phase ◽  
Chromatographic Method ◽  
Glacial Acetic Acid ◽  
Mobile Phases ◽  
Selection Of

Objective. To investigate the best mobile phase for separation of Paracetamol (PAR) and Caffeine (CAF) using TLC method. Methods. Different mobile phases which were mentioned in literature review were tried and retention times for both PAR and CAF were recorded for each experiment separately. Results : It was found that retardation factors for solvent A Rf (PAR) =0,59 and Rf(CAF)=0,90 ; for solvent B Rf(PAR)=0,92 and Rf(CAF)=0,81; Rf(PAR)=0,22 and Rf (CAF)=0,16. Solvent A is composed of n-hexane-ethyl acetate-ethanol (2.5 + 1.5 + 0.4, v/v/v), solvent B is composed of chloroform,ethyl acetate and ammonia (15,0 + 4,3 + 0,3 v/v/v) and solvent C is composed of methanol,glacial acetic acid and water (25,0 +4,3+70,7 v/v/v ). Conclusion: It was found that the best solvent for separation of CAF and PAR in TLC chromatographic method was composed of n-hexane-ethyl acetate-ethanol (2.5 + 1.5 + 0.4, v/v/v).

Evaluation of Thermospray and Cross-Flow Pneumatic Nebulization as Means of Interfacing a Flame Infrared Emission (FIRE) Radiometer to a High-Performance Liquid Chromatograph

1993 ◽  
Vol 47 (2) ◽  
pp. 192-200 ◽  
Author(s):  
David C. Tilotta ◽  
Christopher K. Y. Lam ◽  
Kenneth W. Busch ◽  
Marianna A. Busch
Keyword(s):  
Acetic Acid ◽  
Mobile Phase ◽  
High Performance ◽  
Cross Flow ◽  
Detection Limits ◽  
Infrared Emission ◽  
High Performance Liquid Chromatograph ◽  
Liquid Chromatograph ◽  
Dual Channel ◽  
Mobile Phases

A cross-flow pneumatic nebulizer and a thermospray nebulizer were each studied as a means of interfacing a flame infrared emission (FIRE) radiometer to a high-performance liquid chromatograph (HPLC). Both nebulizers introduced significant quantities of liquid mobile phase into the FIRE burner, necessitating modifications to the basic burner design and causing temperature changes in the hydrogen/air flame used as the FIRE source. Tailing in the trailing edge of the peak profiles was also observed with the use of pneumatic nebulization and attributed to dead volume present in the nebulizer spray chamber. Flame background caused by the combustion of carbon-containing mobile phases was also a problem, but could be avoided when the FIRE radiometer was operated in the carbon mode by using water as the mobile phase. Flame background from carbon-containing mobile phases could also be electronically subtracted by using a dual-channel, chlorine-specific FIRE radiometer to selectively determine mixtures of chlorinated hydrocarbons in the presence of a chlorine-free mobile phase. Background subtraction had the added advantage of improving the detection limits for organochlorine compounds by a factor of approximately 3. Detection limits for FIRE/HPLC using pneumatic nebulization and the single-channel FIRE radiometer in the carbon mode were estimated as 3.7 μg s−1 (5.5 × 102 μg) for acetic acid and 0.80 μg s−1 (1.2 × 102 μg) for ethanol with water as the mobile phase. FIRE/HPLC detection limits using thermospray nebulization and a dual-channel FIRE radiometer in the chlorine-specific mode were estimated as 6.2 μg s−1 (3.7 × 102 μg) for methylene chloride and 9.7 μg s−1 (5.8 × 102 μg) for carbon tetrachloride with a combustible mixture of 49% acetonitrile, 20% methanol, 30% water, and 1% acetic acid as the mobile phase.

scholarly journals Retention behavior of selected alkaloids in Reversed Phase micellar chromatographic systems

2015 ◽  
Vol 28 (2) ◽  
pp. 126-130
Author(s):  
Anna Petruczynik ◽  
Grzegorz Noster ◽  
Monika Waksmundzka-Hajnos
Keyword(s):  
Sodium Dodecyl Sulfate ◽  
Mobile Phase ◽  
Sodium Dodecyl ◽  
Theoretical Plate ◽  
Reversed Phase ◽  
Retention Data ◽  
Organic Modifier ◽  
Mobile Phases ◽  
Theoretical Plate Number ◽  
Dodecyl Sulfate

Abstract In this work, the effects of sodium dodecyl sulfate (SDS) concentrations on retention, separation selectivity, peak shapes and systems efficiency were investigated. Herein, the retention data for 11 alkaloids were determined on an RP18 silica column with mobile phases containing methanol as organic modifier, with acetate buffer at pH 3.5, and, subsequently, with the addition of sodium dodecyl sulfate (SDS). The results of this study indicate that the retention of alkaloids decreases with the increase of SDS concentration in the mobile phase. The increase of SDS concentration, however, leads to the significantly improvement of peak symmetry and the increase of theoretical plate number in all cases. The best system efficiency for most of the investigated alkaloids was obtained in a mobile phase containing 0.1 M SDS, while most symmetrical peaks were obtained through the addition of 0.3 M of SDS to the mobile phase.

QUANTITATIVE DETERMINATION OF CURCUMIN IN TURMERIC POWDER AND TURMERIC–HONEY BALL PILLS BY HPLC

2018 ◽  
Vol 8 (4) ◽  
pp. 42-47
Author(s):  
Tien Nguyen Huu ◽  
Tram Le Thi Bao ◽  
Ngoc Nguyen Thi Nhu ◽  
Thang Phan Phuoc ◽  
Khan Nguyen Viet
Keyword(s):  
Acetic Acid ◽  
Gastric Mucosa ◽  
Quantitative Determination ◽  
Mobile Phase ◽  
Curcuma Longa ◽  
Biological Marker ◽  
Hplc Method ◽  
Chromatography Analysis ◽  
Precision And Accuracy

Background: Curcumin is a major ingredient in turmeric (Curcuma longa L., Zingiberaceae), which has important activities such as anti-tumor, anti-inflammatory, antioxidant, anti-ischemia, protection of gastric mucosa etc,. Curcumin can be considered as a biological marker of turmeric and turmeric products. Objectives: Developing an HPLC method for quantification of curcumin in turmeric powder and turmeric - honey ball pills; applying this method for products on the market. Materials and methods: turmeric powder and turmeric - honey ball pills collected in Thua Thien Hue province. After optimization process, the method was validated and applied to evaluate the content of curcumin. Results: The chromatography analysis was performed with: Zorbaz Eclipse XDB-C18 (150 × 4.6 nm; 5 µm); Mobile phase: acetonitril: 2% acetic acid (45:55), Flow rate was kept constant at 1.0 ml/min; Detector PDA (420 nm). The method was validated for the HPLC system compatibility, specificity, linearity range, precision and accuracy; the recovery greater than 98%. Conclusion: The developed HPLC method can determine curcumin in turmeric powder and turmeric - honey ball pills. Key words: Curcumin, turmeric powder, turmeric-honey ball pills, quantitative determination, HPLC

HPLC-UV Method for Determination of Famotidine from Pharmaceutical Products

2018 ◽  
Vol 69 (2) ◽  
pp. 297-299
Author(s):  
Adriana Nita ◽  
Delia Mirela Tit ◽  
Lucian Copolovici ◽  
Carmen Elena Melinte (Frunzulica) ◽  
Dana Maria Copolovici ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Quantitative Analysis ◽  
Linear Response ◽  
Mobile Phase ◽  
Acetic Acid Solution ◽  
Pharmaceutical Products ◽  
Quantification Limit ◽  
Validation Parameters ◽  
Hplc Analyses

The aim of this study was to develop and validate a rapid, accurate, and exact method for the quantitative determination of famotidine in pharmaceutical products. The HPLC analyses were performed by using a mobile phase containing methanol:1% acetic acid solution=30:7 (v/v), at a flow rate of 0.4 mL/min.The total time of the method was 10 min, and the retention time of famotidine was 4.16 min. The detection was evaluated at l=267 nm. The method has been validated by using different validation parameters. The linear response of the detector for famotidine peak area was observed at concentrations ranging from 0.1 to 0.0001 mg mL-1 , resulting in a correlation coefficient of 0.99998. The values of the detection limit and of the quantification limit are 0.00048 mg mL-1 and 0.00148 mg mL-1, respectively. The method proposed allowed accurate (with a relative error of less than 2%) and precise (RSD values less than 2.0%) determination of famotidine content in pharmaceutical products and can be used for its rapid quantitative analysis.

Development of HPLC Method for the Purity Test by Design of Experiments and Determination of Activation Energy of Hydrolytic Degradation Reactions of Sofosbuvir

2020 ◽  
Vol 16 (7) ◽  
pp. 976-987
Author(s):  
Jakub Petřík ◽  
Jakub Heřt ◽  
Pavel Řezanka ◽  
Filip Vymyslický ◽  
Michal Douša
Keyword(s):  
Activation Energy ◽  
Design Of Experiments ◽  
Mobile Phase ◽  
Hydrolytic Degradation ◽  
Isoconversional Method ◽  
Hplc Method ◽  
Organic Modifier ◽  
Calculation Methods ◽  
Degradation Reactions

Background: The present study was focused on the development of HPLC method for purity testing of sofosbuvir by the Design of Experiments and determination of the activation energy of hydrolytic degradation reactions of sofosbuvir using HPLC based on the kinetics of sofosbuvir degradation. Methods: Following four factors for the Design of Experiments were selected, stationary phase, an organic modifier of the mobile phase, column temperature and pH of the mobile phase. These factors were examined in two or three level experimental design using Modde 11.0 (Umetrics) software. The chromatographic parameters like resolution, USP tailing and discrimination factor were calculated and analysed by partial least squares. The chromatography was performed based on Design of Experiments results with the mobile phase containing ammonium phosphate buffer pH 2.5 and methanol as an organic modifier. Separation was achieved using gradient elution on XBridge BEH C8 at 50 °C and a flow rate of 0.8 mL/min. UV detection was performed at 220 nm. The activation energy of hydrolytic degradation reactions of sofosbuvir was evaluated using two different calculation methods. The first method is based on the slope of dependence of natural logarithm of the rate constant on inverted thermodynamic temperature and the second approach is the isoconversional method. Results and Conclusion: Calculated activation energies were 77.9 ± 1.1 kJ/mol for the first method and 79.5 ± 3.2 kJ/mol for the isoconversional method. The results can be considered to be identical, therefore both calculation methods are suitable for the determination of the activation energy of degradation reactions.

scholarly journals Gradient HPLC in the determination of drug lipophilicity and acidity

2001 ◽  
Vol 73 (9) ◽  
pp. 1465-1475 ◽  
Author(s):  
Roman Kaliszan ◽  
Piotr Haber ◽  
Tomasz Baczek ◽  
Danuta Siluk
Keyword(s):  
Mobile Phase ◽  
High Performance ◽  
Standard Procedure ◽  
Gradient Elution ◽  
Log P ◽  
Retention Data ◽  
Organic Modifier ◽  
Wide Range ◽  
Aqueous Component ◽  
Initial Ph

The linear-solvent strength (LSS) model of gradient elution in high-performance liquid chromatography (HPLC) has been demonstrated to provide parameters of lipophilicity and acidity of analytes. pKa and log kw values are determined in three gradient runs. The first two experiments use an aqueous buffered eluent with a wide-range organic modifier gradient at pH of buffer, providing suppression of ionization of the analyte. That experiment allows an estimate of contents of the organic modifier in the mobile phase (%B), producing requested retention coefficient, k, for the nonionized form of the analyte. The next experiment is carried out with the latter %B and a pH-gradient of the aqueous component of the eluent that is sufficient to overlap possible pKa value of the analyte. The initial pH of the buffer used to make the mobile phase is selected to insure that the analyte is in nonionized form. The resulting retention time allows an estimate of pKa in a solvent of the given %B.The log kw parameter obtained correlated well with the corresponding value obtained by the standard procedure of extrapolation of retention data determined in a series of isocratic measurements. The correlation between log kw and the reference parameter of lipophilicity, log P, was very good for a series of test analytes. The values of pKa were found to correlate with the literature pKa data determined in water for a set of aniline derivatives studied.

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