RESUMEN
A new experimental design method named the step climbing method (SCM), as well as a new global criterion (NRC), are proposed for the selectivity optimization of thin layer chromatography. The method offers chromatographers a convenient means to decide the optimum developer composition for thin layer chromatography. The principle of the method is described, and examples of applications in pharmaceutical analysis are given to certify the feasibility of the method. Clearly, it may also be used for the selectivity optimization in high performance liquid chromatography.
Asunto(s)
Cromatografía en Capa Delgada/métodos , Cefalotina/análisis , Medicamentos Herbarios Chinos/análisis , Materia Medica/análisis , MatemáticaRESUMEN
An HPLC method was established to separate and determine ephedrine (I), pseudoephedrine (II) and strychnine (III) in Chinese traditional medicine, Jiufen San, on a mu-Bondapak C18 column (10 microns, 3.9 mm x 30 cm) by using 0.01 mol/L KH2PO4-methanol as mobile phase. The programmed gradient elution was carried out and recoveries were determined as 98.94 +/- 2.2% for I, 97.37 +/- 1.9% for II and 100.7 +/- 1.9% for III respectively. An extracting and pretreatment method was designed and the result showed that the extracting efficiency of this method was 1.33 times (I) and 1.29 times (II) higher than those of the Chinese Pharmacopoeia method.
Asunto(s)
Medicamentos Herbarios Chinos/química , Efedrina/análisis , Estricnina/análisis , Cromatografía Líquida de Alta Presión , Combinación de Medicamentos , PolvosRESUMEN
This paper describes that the absorption spectrum of bilirubin solution was changed obviously by photo-oxidation. The absorbance was measured at 453 nm before and after light irradiation. The contents of bilirubin of ox gallstone in Liuying pills, Liushen pills and Niuhuang Xiaoyan pills were determined by differential absorbance (delta A). Calibration graph was linear in the range of 1.6-8.0 micrograms/ml for delta A. The average recoveries for three Chinese patent medicines were over 93%. Determinations of bilirubin in Chinese patent medicines were not affected by other components.