scholarly journals Effect of mobile phase buffer pH on separation selectivity of some isoquinoline alkaloids in reversed-phase systems of Pressuriz

2015 ◽  
Vol 26 (3) ◽  
pp. 45-49
Author(s):  
Ewelina Kopciał ◽  
Beata Polak ◽  
Rafał Pietraś ◽  
Paulina Mączka ◽  
Tadeusz H. Dzido
Keyword(s):  
Mobile Phase ◽  
High Performance ◽  
Reversed Phase ◽  
Retardation Factor ◽  
Isoquinoline Alkaloids ◽  
Buffer Solution ◽  
Separation Selectivity ◽  
Phase Systems ◽  
Ph Range ◽  
Layer Chromatography

Separation of some isoquinoline alkaloids (narcotine, chelidonine, dihydrocodeine, cinchonine, berberine, cinchonidine, papaverine, apomorphine) has been investigated with pressurized planar electrochromatography (PPEC) and high-performance thin-layer chromatography (HPTLC) in reversed-phase systems. The mobile phase consisted of acetonitrile and aqueous buffer (disodium phosphate and citric acid). The influence of the mobile phase buffer pH on migration distance (PPEC) and retardation factor (HPTLC) of the solutes has been investigated and compared. The results show different separation selectivity in both PPEC and HPTLC systems especially at pH range of buffer solution of the mobile phase that facilitates ionization of the solutes investigated.

scholarly journals Separation of 9-Fluorenylmethyloxycarbonyl Amino Acid Derivatives in Micellar Systems of High-Performance Thin-Layer Chromatography and Pressurized Planar Electrochromatography

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Beata Polak ◽  
Adam Traczuk ◽  
Sylwia Misztal
Keyword(s):  
Amino Acid ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Mobile Phase ◽  
High Performance ◽  
Reversed Phase ◽  
Amino Acid Derivatives ◽  
Solute Retention ◽  
Micellar Systems ◽  
Layer Chromatography

AbstractThe problems with separation of amino acid mixtures in reversed-phase mode are the result of their hydrophilic nature. The derivatisation of the amino group of mentioned above solutes leads to their solution. For this purpose, 9-fluorenylmethoxycarbonyl chloroformate (f-moc-Cl) as the derivatisation reagent is often used. In our study, the separation of some f-moc- amino acid derivatives (alanine, phenylalanine, leucine, methionine, proline and tryptophan) with the use of micellar systems of reversed-phase high-performance thin-layer chromatography (HPTLC) and pressurized planar electrochromatography (PPEC) is investigated. The effect of surfactant concentration, its type (anionic, cationic and non-ionic) and mobile phase buffer pH on the discussed above solute migration distances are presented. Our work reveals that the increase of sodium dodecylsulphate concentration in the mobile phase has a different effect on solute retention in HPTLC and PPEC. Moreover, it also affects the order of solutes in both techniques. In PPEC, in contrast to the HPTLC technique, the mobile phase pH affects solute retention. The type of surfactant in the mobile phase also impacts solute retention and migration distances. A mobile phase containing SDS improves system efficiency in both techniques. Herein, such an effect is presented for the first time.

scholarly journals Rapid, Highly-Sensitive and Ecologically Greener Reversed-Phase/Normal-Phase HPTLC Technique with Univariate Calibration for the Determination of Trans-Resveratrol

Separations ◽  
2021 ◽  
Vol 8 (10) ◽  
pp. 184
Author(s):  
Prawez Alam ◽  
Faiyaz Shakeel ◽  
Mohammed H. Alqarni ◽  
Ahmed I. Foudah ◽  
Mohammed M. Ghoneim ◽  
...  
Keyword(s):  
Mobile Phase ◽  
High Performance ◽  
Reversed Phase ◽  
Normal Phase ◽  
Commercial Formulation ◽  
Highly Sensitive ◽  
Validation Parameters ◽  
Layer Chromatography ◽  
Chloroform Methanol

The rapid, highly-sensitive and ecologically greener reversed-phase (RP)/normal-phase (NP) high-performance thin-layer chromatography (HPTLC) densitometric technique has been developed and validated for the determination of trans-resveratrol (TRV). The reversed-phase HPTLC-based analysis of TRV was performed using ethanol–water (65:35, v v−1) combination as the greener mobile phase, while, the normal-phase HPTLC-based estimation of TRV was performed using chloroform–methanol (85:15, v v−1) combination as the routine mobile phase. The TRV detection was carried out at 302 nm for RP/NP densitometric assay. The linearity was recorded as 10–1200 and 30–400 ng band−1 for RP and NP HPTLC techniques, respectively. The RP densitometric assay was observed as highly-sensitive, accurate, precise and robust for TRV detection in comparison with the NP densitometric assay. The contents of TRV in commercial formulation were recorded as 101.21% utilizing the RP densitometric assay, while, the contents of TRV in commercial formulation were found to be 91.64% utilizing the NP densitometric assay. The greener profile of RP/NP technique was obtained using the analytical GREEnness (AGREE) approach. The AGREE scales for RP and NP densitometric assays were estimated 0.75 and 0.48, respectively. The recorded AGREE scale for the RP densitometric assay indicated that this technique was highly green/the ecologically greener compared to the NP densitometric assay. After successful optimization of analytical conditions, validation parameters, AGREE scale and chromatography performance, the RP densitometric assay with univariate calibration was found to be better than the NP densitometric assay for the analysis of TRV.

scholarly journals Separation of some vitamins in reversed-phase thin-layer chromatography and pressurized planar electrochromatography with eluent containing surfactant

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Beata Polak ◽  
Emilia Pajurek
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Mobile Phase ◽  
High Performance ◽  
Theoretical Plate ◽  
Reversed Phase ◽  
Water Soluble ◽  
System Capacity ◽  
Micellar Systems ◽  
Layer Chromatography

AbstractThe separation of some water- and fat-soluble vitamins via micellar systems of reversed-phase high-performance thin-layer chromatography (HPTLC) and pressurized planar electrochromatography (PPEC) was subjected to research. Hence, the influence of the mobile phase composition (surfactant and acetonitrile concentration, eluent buffer pH) on the migration distances and zone separation of some vitamins (thiamine, riboflavin, niacin, pyridoxine, cyanocobalamin, folic acid, ergocalciferol and α-tocopherol) was investigated. Our results indicated that the applied technique has an impact on the solute order. Comparing the system capacity of HPLC and PPEC (measured as height of the theoretical plate) for the mobile phase systems with and without surfactant shows differences, especially for fat-soluble vitamin. The variances and reproducibilities (% RDS) values of the vitamin are less in PPEC than in TLC. Moreover, the migration distances of water-soluble vitamins are longer than fat-soluble ones. Overall, eluent consisting of 50% acetonitrile, 18.75 mM SDS, the buffer of pH 6.99 via the PPEC technique was most appropriate for determining the investigated vitamins in the artificial mixture and the two commercially available vitamin combinations.

Applications of Reversed-Phase High-Performance Liquid Chromatoraphy in Strains Identification of the Bean Sprout

2011 ◽  
Vol 347-353 ◽  
pp. 354-359
Author(s):  
Yong Zuo ◽  
Shuai Ju ◽  
Yang Li ◽  
Hui Xie ◽  
Li Ping Liu ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Mobile Phase ◽  
High Performance ◽  
Phosphate Buffer Solution ◽  
Reversed Phase ◽  
Qualitative And Quantitative Analysis ◽  
Buffer Solution ◽  
Solution Ph ◽  
Bean Sprout ◽  
Qualitative And Quantitative

Lactic acid which was fermented by bean sprout was determined and the lactobacillus in bean sprout was identified by High-performance Liquid Chromatoraphy(HPLC). The optimal HPLC chromatographic conditions were determined as follows:Agilent XDB-C18 chromatography column with UV detection at 210nm.The mobile phase was Phosphate buffer solution（pH=2.3）:methanol:acetonitrile（95%:2%:3%）.The flow rate was 0.5ml/min.This method is accurate,Speedily and reproducible. This method can identify the lactobacillus, and gives a qualitative and quantitative analysis of the lactic acid which was the metabolites of Yibin bean sprout.

scholarly journals Pressurized planar electrochromatography of DNS amino acids derivatives in silica gel and silanized silica gel systems with formic acid addition to the water mobile phase

2021 ◽  
Author(s):  
Adam Chomicki ◽  
Tadeusz H. Dzido
Keyword(s):  
Amino Acids ◽  
Silica Gel ◽  
High Performance ◽  
Reversed Phase ◽  
Mobile Phases ◽  
Phase Systems ◽  
Silanized Silica ◽  
Layer Chromatography ◽  
Derivatives Of ◽  
Electrophoretic Effect

AbstractPressurized planar electrochromatography (PPEC) of dansyl (DNS) derivatives of amino acids in normal- and reversed-phase systems is presented. The results have been obtained for mobile phases with different acetonitrile (ACN) concentrations (0–85%). The data obtained show differences in separation selectivity between high-performance thin-layer chromatography (HPTLC) and PPEC systems. These differences originate from the electrophoretic effect which is involved in the PPEC system, contrary to the HPTLC one.

scholarly journals Assay of Tinidazole in Human Serum by High-Performance Thin-Layer Chromatography—Comparison with High-Performance Liquid Chromatography

1999 ◽  
Vol 82 (2) ◽  
pp. 244-247 ◽  
Author(s):  
M H Guermouche ◽  
D Habel ◽  
S Guermouche
Keyword(s):  
High Performance Liquid Chromatography ◽  
Thin Layer ◽  
Human Serum ◽  
Thin Layer Chromatography ◽  
Mobile Phase ◽  
High Performance ◽  
Reversed Phase ◽  
Reversed Phase Hplc ◽  
Layer Chromatography

Abstract Determination of tinidazole in human serum by high-performance thin-layer chromatography (HPTLC) is presented. It includes use of 10 × 10 cm plates coated with silica gel 60 and chloroform-acetonitrile-acetic acid (60 + 40 + 2) as mobile phase. Quantitation was performed by densitometry at 320 nm. The linearity (1-10 ng), precision (6%), reproducibility (5%), recovery (96%), and detection limit (1 mg/L) of tinidazole determination by HPTLC were comparable with corresponding method parameters by reversed-phase HPLC. A satisfactory correlation was found between the 2 analytical methods. The procedure was used to quantitate tinidazole in patient sera.

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.

scholarly journals Determination of the Lipophilicity of Ibuprofen, Naproxen, Ketoprofen, and Flurbiprofen with Thin-Layer Chromatography

2019 ◽  
Vol 2019 ◽  
pp. 1-6 ◽  
Author(s):  
Andrzej Czyrski
Keyword(s):  
Thin Layer ◽  
Stationary Phase ◽  
Thin Layer Chromatography ◽  
Human Body ◽  
Mobile Phase ◽  
High Performance ◽  
Reversed Phase ◽  
Regression Curve ◽  
Layer Chromatography

The lipophilicity is an important parameter that influences the activity of the drugs in the human body. The reversed phase high performance thin layer chromatography was applied to determine the Log P values of ibuprofen, ketoprofen, naproxen, and flurbiprofen. The stationary phase used in the study was silica-gel coated plates. The mobile phase was the mixture of acetonitrile and water in different proportions. The content of acetonitrile varied in 5% increments from 50% to 80%. The Rm0 values were determined for the compounds with a known Log P and for the analyzed substances (ibuprofen, naproxen, ketoprofen, and flurbiprofen). The Log P values were calculated for the analyzed compounds using the regression curve Rm0 = f(Log P) parameters for the compounds with the known lipophilicity. Flurbiprofen is characterized by the highest Log P value: 3.82. The lowest one is noted for ketoprofen: 2.66. The determined Log P values of tested compounds were similar to the values calculated by the software.

scholarly journals Spectrofluorometry, Thin Layer Chromatography, and Column High-Performance Liquid Chromatography Determination of Rabeprazole Sodium in the Presence of Its Acidic and Oxidized Degradation Products

2009 ◽  
Vol 92 (5) ◽  
pp. 1373-1381 ◽  
Author(s):  
Afaf Osman ◽  
Mohamed Osman
Keyword(s):  
Mobile Phase ◽  
High Performance ◽  
Degradation Products ◽  
Reversed Phase ◽  
Ir Spectrometry ◽  
Intact Drug ◽  
Rabeprazole Sodium ◽  
Acidic Degradation ◽  
Layer Chromatography

Abstract The objective of this study is to develop validated stability-indicating spectrofluorometric, TLC-densitometric, and HPLC methods for the determination of rabeprazole sodium and its degradation products. The first method was based on measuring the fluorescence intensity of the drug at 416 and 311 nm for the emission and at 320 and 274 nm for the excitation for acid and oxidized solutions, respectively. The second method was based on the separation of the drug from its acidic and oxidized degradation products followed by densitometric measurement of the intact drug spot at 284 nm. The separation was carried out on Fluka TLC sheets of silica gel 60 F254 using isopropyl alcohol30 ammonia (80 + 2, v/v) mobile phase. The third method was based on HPLC separation of rabeprazole sodium from its acidic and oxidized degradation products on a reversed-phase Waters Nova-Pak C18 column using 0.05 M potassium dihydrogen phosphatemethanolacetonitrile (5 + 3 + 2, v/v/v) pH 7 0.2 mobile phase. The proposed procedures were successfully applied for the determination of rabeprazole sodium in pure form, laboratory-prepared mixtures, tablet, and expired batch. The obtained results were statistically compared with those of a reported method and validated according to United States Pharmacopeia guidelines. Two main acidic degradation products of the drug were separated and subjected to IR spectrometry and MS to confirm their structures, and the schemes for their formation were elucidated.

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