separation of ten sedative- hypnotic drugs was performed by rp-hplc using mixed micellar mobile phase. effect of temperature, type and amount of organic modifier in mobile phase on efficiency (n) and asymmetry factor (b/a) showed that, the appropriate conditions for a good separation were 35°c and 7% (v/v) butanol in mobile phase.  variations of selectivity factor versus butanol concentration, ...

Across evolution, dolichols and polyprenols serve as sugar carriers in biosynthetic processes that include protein glycosylation and lipopolysaccharide biogenesis. Liquid chromatography coupled with electrospray ionization mass spectrometry offers a powerful tool for studying dolichols and polyprenols in their alcohol or glycan-modified forms in members of all three domains of life. In the foll...

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...

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...

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...

There is no other naturally occurring defense agent against cancer that has a stronger effectthan paclitaxel, commonly known under the brand name of Taxol®. The major drawback for themore widespread use of paclitaxel and its precious precursor, 10-deacetylbaccatin III (10-DABIII), is that they require large-scale extraction from different parts of yew trees (Taxus species),cell cultures, taxane...

results under the above chromatography condition, biuret compound (peqb) and the internal standard were detected at 4.5 and 13.5 minutes, respectively. limit of quantitation of the peqb was 0.1 µg/ml. accuracy of the method over the concentration range of 0.1-100 µg/ml was between 88-109%. inter- and intraday precisions were 4-19% and 6-8%, respectively. a good relationship in the form of a pow...

Reversed-phase chromatography is a method that is often used for glycan separation. For this, glycans are often derivatized with a hydrophobic tag to achieve retention on hydrophobic stationary phases. The separation and elution order of glycans in reversed-phase chromatography is highly dependent on the hydrophobicity of the tag and the contribution of the glycan itself to the retention. The c...

Poly(L-lactic acid) is a linear aliphatic thermoplastic polyester that can be produced from renewable resources. A poly(L-lactic acid)-modified silica stationary phase was newly prepared by amide bond reaction between amino groups on aminopropyl silica and carboxylic acid groups at the end of the poly(L-lactic acid) chain. The poly(L-lactic acid)-silica column was characterized in reversed-phas...