Ethanol In Mobile Phase Research Articles

Derivatization of Proline for the Enantiomeric Separation and Estimation of D-Proline in L-Proline by NP-HPLC

The core object of this exertion is to progress and validate a modest, competent and explicit method for the exodus of D and L isomers of proline in a racemic mixture and limit the content of D-Proline in commercial L-Proline. This has been technologically advanced in a chiral method using normal phase HPLC on CHIRALPAK-IA (250X4.6 mm) 5 μ column. This progress advanced with polar mobile phase ethanol encompassing modifier/additive TFA in 0.1% concentration. Due to the chromophore’s deficiency in proline, proline’s derivatization has been done using fluorescent reagent NBD-Cl. After derivatization, proline has made UV detectable at 465 nm. Within run time of 20 minutes, D and L isomers of proline were eluted at 6.72 and 9.22 minutes, respectively. The technologically advanced method was validated as per ICH guidelines. Linearity regression coefficients for both D and L-Proline are obtained as 0.999. Retrieval for D-Proline was obtained at 93 to 95% range for 4 levels. LoD and LoQ for both D- and L-Proline were detected as 0.6 and 2 ppm, respectively. Hence this method is newer, modest, particular and explicit chiral method.

IDENTIFIKASI PARASETAMOL DALAM JAMU PEGAL LINU YANG DIPEROLEH DARI DEPOT JAMU DI KOTA DENPASAR

The use of traditional medicine in the form of herbal medicine is in great demand by the people of Indonesia, one of that is pegal linu herb. Based on PERMENKES No. 006/Menkes/Per/V/2012 articles 33 and 37 states that traditional medicine may not contain medicinal chemical. Medicinal chemical that is often added into herbal medicine for pegal linu herb is paracetamol.This study aims to determine the presence of paracetamol in pegal linu herb depots in Denpasar city. The research method used an exploratory descriptive method and samples of herbal medicine were taken by purposive sampling, 14 samples of herbal medicine of various brands that was sold at depots in Denpasar City. The research was conducted at the chemical laboratory of Bali International University in July 2021. After preparation, the fourteen samples of herbal medicine were identified using Thin Layer Chromatography (TLC) with selection mobile phase ethanol p.a, detection with UV light 254 nm and 0.05 M H2SO4 sprayer. Completeness identification was also carried out descriptive labeling of herbal products containing paracetamol. Positive samples contain paracetamol if the Rf value and spot color are similar to the paracetamol comparison standard. The Rf results obtained that samples with codes F, I, K, and L were 0.68; 0.68; 0.68 and 0.68 which are the similar as the standard Rf for comparison of paracetamol and positive control which is 0.69. The conclusion of the research is that there are various brands of pegal linu herb sold in Indonesia that are suspected to contain 4 brands of paracetamol. Research suggestions for consumers who consume a brand of traditional herbal medicine are expected to be more selective in choosing herbal medicine by first checking the product registration number.

Eco-friendly chiral HPLC method for determination of alfuzosin enantiomers and solifenacin in their newly pharmaceutical combination: Method optimization via central composite design

The high abundance and advantages of polysaccharides make them among the most widely used chiral stationary phases in liquid chromatography. However, extended analysis time and consumption of toxic organic solvents, associated with traditional columns, remain the main stumbling blocks of such methods’ sustainability. A new green chiral HPLC-separation, with just 0.45 mL ethanol in mobile phase per run utilizing a 50-mm column as a stationary phase, achieves a significant determination of alfuzosin (ALF) enantiomers along with solifenacin (SOL) simultaneously. Enantioseparation of ALF was firstly evaluated in the reversed-phase mode using five polysaccharide-based Lux columns (Amylose 2 and Cellulose 1–4), highlighting Lux Cellulose 2 to reach the best enantioselectivity. Central composite design with Derringer's desirability function was then adopted to optimize the chromatographic conditions for an acceptable resolution. A mobile phase composed of ethanol and phosphate buffer, pH 4, (30:70, v/v) at a rate of 0.5 mL/min with UV-detection at 215 nm, exhibits good separation of ALF-enantiomers from SOL with resolution values of 1.45 and 2.64, respectively. The method’s greenness profile has been assessed and compared with that of mostly reported ones via the newest comprehensive analytical method greenness score (AMGS) calculator. The proposed method is considered a straightforward approach towards safer, more economic, eco-friendly and comparatively favorable for the cited drugs’ quantification in their formulation.

TLC-based enantiomeric separation of amino acids onto β-CD-incorporated glutaraldehyde-crosslinked PVA electrospun fiber stationary phase

Simple and economical methods for chiral separations are always needed in synthesis and drug development and as biomarkers, besides many other useful applications. Cyclodextrins (CDs) are chiral host molecules and have been used to separate a number of chiral analytes. In this study, we have successfully prepared electrospun films of β-CD incorporated into polyvinyl alcohol (PVA) through glutaraldehyde (GA) crosslinking. These films of β-CD-PVA-GA electrospun fibers are characterized by Fourier transform infrared (FTIR) and scanning electron microscopy (SEM), which were subsequently used for thin-layer chromatography (TLC)-based enantiomeric separation of histidine and serine pairs. Amino acids were detected by spraying the chromatograms with the ninhydrin solution. Among various solvent systems employed, it was found that the separation of serine enantiomers with a resolution of 1.6 was possible with the mobile phase ethanol–butanol–ethyl acetate–water–acetone (4:5:5:0.5:1.5,v/v), and histidine enantiomers with a resolution of 1.4 were possible with the mobile phase ethanol–butanol–ethyl acetate–water–acetone (4:5:4.5:0.5:1.5,v/v). This proves that the prepared stationary phase is efficient in enatioresolution of selected amino acid pairs and can be further examined for physiological samples.

Separation and Detection of Caffeine, Theophylline and Theobromine from Coffee Varieties, Carbonated Soft Drinks and Alcoholic Beverages

The paper evaluates the presence of methyl xanthine compounds: caffeine, theophylline, theobromine used as ingredients in carbonated soft drinks or as color and flavor ingredients in alcoholic beverages. The active components extracted from the selected products (coffee, tea, drinks) was separated and identified chromatographically using plates with silica nano -Sil NH2 / UV-254, mobile phase ethanol - water (50: 1, 50: 3, 50: 5; 50: 7; v / v) and 60 F254 plates, mobile phase acetone-toluene-chloroform (40:30:30 v / v). Separated caffeine and identified by TLC was analyzed using a HelWet Packard 5890 Gas Chromatograph equipped with MS 5972 mass detector and spectral library to confirm identification. This simple and rapid TLC, GC / MS instrumental method is useful in controlling traces of methyl xanthine compounds in food as a food safety measure.is useful in controlling traces compound of food products containing methylxanthines as a food safety measure.

Analysis of the retention behavior of selected antipsychotics and their impurities by thin-layer chromatography

The retention behavior and lipophilicity of aripiprazole and its nine impurities as well as ziprasidone and its five impurities have been examined by thin-layer chromatography using RP-18 stationary phase and different mixtures of methanol, water, and ammonia; and ethanol, water, and ammonia as the mobile phases. In both examined chromatographic systems, linear relationships were established between retention parameters and the volume fraction of the methanol and ethanol in mobile phase (r > 0.948 for methanol and r > 0.971 for ethanol). Correlation matrices obtained between experimentally obtained lipophilicity indices (RM0, m, and C0) and calculated log P values showed that, for the examined antipsychotics and their impurities, RM0 and m values are more reliable lipophilicity parameters compared to C0 values. In addition, the performed principal component analysis (PCA) has provided new information about the similarity and differences between the tested compounds as well as the experimental lipophilicit...

Research Article. The Influence of Some Parameters on Chiral Separation of Ibuprofen by High-Performance Liquid Chromatography and Capillary Electrophoresis

Abstract Objective: The aim of the study was to compare the influence of mobile phase composition and temperature on chiral separation of racemic ibuprofen by capillary electrophoresis and high performance liquid chromatography with UV detection. Materials and methods: Racemic ibuprofen was analysed on a chiral OVM column with an HPLC system 1100 Agilent Technologies, under isocratic elution, by using potassium dihydrogen phosphate 20 mM and ethanol in mobile phase. The flow rate was set at 1 mL/min, UV detector at 220 nm and different column temperatures were tested. For electrophoresis separation an Agilent CE G1600AX Capillary Electrophoresis System system, with UV detection, was used. The electrophoresis analysis was performed at different pH values and temperatures, with phosphate buffer 25 mM and methyl-β-cyclodextrin as chiral selector. Results: The chromatograhic analysis reveals a high influence of mobile phase pH on ibuprofen enantiomers separation. An elution with a mixture of potassium dihydrogen phosphate 20 mM pH=3 and ethanol, at 25°C, allowed enantiomers separation with good resolution in less than 8 min. Conclusions: The proposed HPLC method proved suitable for the separation of ibuprofen enantiomers with a good resolution, but the capillary electrophoresis tested parameters did not allow chiral discrimination.

Enantiomeric determination and evaluation of the racemization process of atropine in Solanaceae seeds and contaminated samples by high performance liquid chromatography-tandem mass spectrometry

A new method has been developed for the enantioselective separation of (−) and (+) hyoscyamine in Solanaceaes seeds and contaminated buckwheat. Chromatographic separation was optimized, evaluating two chiral columns, Chirobiotic V and Chiralpal-AY3. Better resolution was obtained using a Chiralpak-AY3 column, utilizing as mobile phase ethanol (0.1% diethanolamine). An extraction procedure based on a modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) was applied, using water and acetonitrile containing 1% of acetic acid, and a clean-up step utilizing primary secondary amine (PSA) and graphitized carbon black (GCB) as sorbents. The extract was diluted with ethanol (50/:50, v/v) prior to chromatographic analysis, and the separation was carried out avoiding the racemization during this stage. Enantiomerization process of atropine was studied in samples at different conditions such as temperature (30, 50 and 80°C) and pH (3, 5, 7 and 9), observing that racemization occurs at high pH (9) and temperature (80°C). Stramonium and Brugmansia seeds were analyzed and the concentration of (−)-hyoscyamine was 1500mg/kg and 320mg/kg respectively. Contaminated buckwheat was also determined and (−)-hyoscyamine was detected at 170μg/kg.

LC determination of aminoglutethimide enantiomers as dansyl and fluorescamine derivatives in tablet formulations

Determination of dansyl (AG-DNS) and fluorescamine (AG-F) derivatives of rac-aminoglutethimide in tablet formulation by HPLC has been achieved on a cellulose tris-(3,5-dimethylphenyl carbamate), known as Chiralcel OD and OD-R under normal and reversed phase columns, respectively, using a fluorescence detector ( λ ex, 360 nm; λ em, 530 nm for AG-DNS derivatives; λ ex, 395 nm, λ em, 495 nm for fluorescamine derivatives (AG-F)). The best results were obtained with mobile phase ethanol:cyclohexane:methanol (95:5:2 v/v/v) for AG-DNS derivatives and acetonitrile:0.5% ortho-phosphoric acid (85:15 v/v) containing 0.26 mM 1-hexanesulfonic acid sodium salt (HSA) for AG-F, respectively. The lower limit of detection (signal to noise ratio of 3:1) were found to be 20 ng ml −1 for each enantiomer for AG-DNS and 20.5 ng ml −1 for each diastreoisomer for AG-F.

HPLC evaluation of diclofenac in transdermal therapeutic preparations

High-performance liquid chromatography (HPLC) was selected for analytical evaluation of sodium diclofenac in original transdermal therapeutic preparations containing adjuvant substances (capsaicin, hyoscyamine). After isolation from laminated adhesive patches, diclofenac was analysed on columns with reversed phase, using the mobile phase ethanol and phosphate buffer (pH 6.5) with an addition of tetrabutylammonium iodide and detection at 284 nm. Not only the total amount of diclofenac in the patch was evaluated, but HPLC methodology was also employed to select a suitable acceptor medium for permeation experiments. In patches manufactured in the tested series, HPLC was also employed to examine the release of diclofenac and its in vitro permeation through the human skin.