摘要:

A highly sensitive and selective method for the determination of valproic acid salts in pharmaceutical tablet formulations by a high performance liquid chromatography method with coulometric electrochemical detection is described. The precolumn derivatizations of valproic acid and the internal standard (n-hexanoic acid) were carried out using 1-(2,5-dihydroxyphenyl)-2-bromoethanone as an electroactive labeling reagent. The resulting electroactive esters were separated by isocratic elution of a 3 μm Adsorbosphere ODS column with methanolacetonitrile-acetate buffer eluent.

ISSN:1082-6076    

DOI:10.1080/10826079808003450

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

The chromatographic behavior of acidic drugs was studied using a guanidino phase in liquid chromatography. The quaternary anion-exchange group, i.e., the guanidino group, acted as a weak anion exchanger and the chromatographic retention capacity was similar to that of a DEAE ion exchanger. Acidic drugs were poorly retained on guanidino phase in a 50mM sodium phosphate buffer at pH7.4.

ISSN:1082-6076    

DOI:10.1080/10826079808003451

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

High-speed countercurrent chromatography (HSCCC) was applied to the separation and purification of 2,3,5,4′-tetrahydroxy stilbene-2-O-D-glucoside from dried roots (2.7g) ofPolygonum multiflorum. The ethanol extract (240 mg) was first separated with the solvent system composed of ethyl acetate-ethanol-water at a volume ratio of 10:1:10 and the obtained fraction was repurified with the solvent system at the modified volume ratio of 50:1:50. The method produced stilbene glucoside (30mg) at a high purity of 96%. The chemical structure was identified by FAB-MS and1HNMR.

ISSN:1082-6076    

DOI:10.1080/10826079808003452

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

ISSN:1082-6076    

DOI:10.1080/10826079808003453

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

ISSN:1082-6076    

DOI:10.1080/10826079808003454

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

ISSN:1082-6076    

DOI:10.1080/10826079808003455

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor