The activity of silaceous capillary columns for gas-liquid chromatography

✍ Scribed by Pretorius, Victor ;Desty, D. H.

• Publisher: John Wiley and Sons
• Year: 1981
• Tongue: English
• Weight: 184 KB
• Volume: 4
• Category: Article
• ISSN: 0935-6304
• DOI: 10.1002/jhrc.1240040111

✦ Synopsis

The extract was filtered and the filtrate diluted with an equal volume of water. 50 ml strong solution of lead subacetate was added and the mixture centrifuged after 5 minutes. Excess lead was precipitated with 10% disodium hydrogen phosphate and the mixture again centrifuged. The supernatant was successively extracted with 3 x 50 ml chloroform, 3 x 50 ml chloroform-methanol (1 :l)and 3x50 ml chloroform.Thecombinedchloroformicextracts were dried over sodium sulphate and evaporated to dryness under reduced pressure. The residue was dissolved in 80% methanol and further purified by elution through neutral aluminia. The eluate was evaporated to dryness and the residue dissolved in 4 ml of chloroform-methanol (1:l) for HPLC. A reference mixture of glycosides was prepared by dissolving 2 mg of convallatoxin, convallatoxol, convalloside and periplorhamnoside in 1 ml chloroform-methanol (1 :l).

Chromatographic conditions

Column: Partisil PXS 10125 ODS (Whatman); 250 mm x 4 mm id.

Mobile phase: 25% vlv acetonitrile in water.

Flow rate: 1.0 ml min-1 (600 psi).

Detection: Cecil Instruments CE272 spectrophotometer at 222 nm. Injection: 20 pl (by capillary loop).