this study aimed to construct the hydrate three-phase equilibrium curves for two typical iranian gas reservoir samples using a high-pressure visual cell. to do so, complete analysis of the reservoir fluids was obtained by different techniques of composition analysis i.e. gas chromatography (gc) and detailed hydrocarbon analysis (dha). using high-pressure visual cell the hydrate phase equilibriu...

We describe the use of electron-capture gas chromatography or reversed-phase "high-performance" liquid chromatography for concurrent analysis for diazepam and nordiazepam in serum. In the gas-chromatographic analysis our use of a new chemically deactivated stationary liquid phase, SP 2250-DB (Supelco, Inc.), resulted in improved chromatographic sensitivity and peak symmetry for the two benzodia...

Liquid chromatography is a very important separation method used in practically all chemistry fields. For many decades, it has played a key role in academic and industrial laboratories where it is used to analyze or purify components from complex mixtures. For example, it is used to separate proteins/drugs from impurities and to analyze drugs and endogenous components in biological materials. M...

Abbreviations: AIBN, 2,20-azo-bis-isobutyronitrile; ASE, Accelerated solvent extraction; CAR, Carboxen; DAD, Diode-array detector; DI-SPME, Direct-immersion solid-phase extraction; DSPE, Dispersive solid-phase extraction; EGDMA, Ethylene glycol dimethacrylate; ESE, Enhanced solvent extraction; ESI, Electrospray ionization; FD, Fluorescence detection; FLD, Fluorimetric detection; GC, Gas chromat...

In this study, hollow fiber liquid phase microextraction (HF-LPME) coupled with highperformanceliquid chromatography (HPLC) with UV detection was applied for preconcentrationand determination of Diclofenac sodium in biological fluids. Parameters affecting the extractionprocess including pH of donor phase and acceptor phase, type of extraction solvent, stirring rate,extraction time, and salt add...

of isotopically labelled vitamin D metabolites by HPLC. Journal of Chromatography 303: 229}233. Kaspersen FM, van Acquoy J, van de Laar GLM, Wagenaars GN and Funke CW (1984) Deuterium isotope effects in mianserin. Recueil Travaux Chimique de Pay-Bas 103: 32}36. Klein PD (1966) Occurence and signiRcance of isotope fractionation during analytical separation of large molecules. Advances in Chromat...

BACKGROUND Hydrophilic interaction chromatography (HILIC) is becoming an increasingly popular alternative to traditional reversed-phase chromatography for the analysis of polar compounds. The ability to retain the most polar compounds in HILIC makes it attractive for the analysis of certain large groups of compounds, such as monoamines, which are inherently very polar. RESULTS This paper deta...

The first oligonucleotide therapeutic was approved by the Food and Drug Administration in 1998, since then, 12 nucleic acids have been commercialised as medicines. To be approved, oligonucleotides need to identified characterised well its related impurities. Different methods exist, but most commonly used is ion-pairing reversed-phase liquid chromatography with tandem mass spectrometry. separat...

Mobile phase optimization is highly important in planar chromatography. Solvent selection based on experience and chromatographic intuition can be very time consuming when applied to complex mixtures. In these cases, more systematic strategies are needed. This paper presents a new mathematical model for the optimization of the mobile phase composition used for the separation of a mixture of 1,4...

Submit Manuscript | http://medcraveonline.com Abbreviations: NMR: Nuclear Magnetic Resonance; HPLC: High Performance Liquid Chromatography; RP-HPLC: Reverse Phase High Performance Liquid Chromatography; HPTLC: High Performance Thin Liquid Chromatography; TLC: Thin Liquid Chromatography; API’s: Active Pharmaceutical Ingredient’s; LOD: Limit of Detection; LOQ: Limit of Quantitation; FTIR: Fourier...