Solid tropane alkaloids

Another major drawback of classical extractions is that additional clean-up procedures are frequently required before chromatographic analyses. Solid phase extraction (SPE) avoids the emulsion problems often encountered in liquid-liquid extraction. A wide range of adsorbents are commercially available and may be divided into three classes polar, ion-exchange, and nonpolar adsorbents. Solid-supported liquid-liquid extraction on Extrelut columns is frequently reported for efficient cleanup of crude tropane alkaloid mixtures. Basifled aqueous solutions of alkaloids maybe transferred to Extrelut columns and the bases recovered in dichloromethane-isopropanol mixture [13]. 

Competitive solid-phase enzyme immunoassay for the evaluation of tropane alkaloids in plant materials using anti-dl-tropic acid antibodies has been reported (154). 

SE-30 (5 %) and Carbowax 20 m (1 %) as stationary phases on Chromosorb 60-80 mesh, acid washed. A solid injector was employed to prevent contamination of the column by non-volatile compounds present in the extracts of the biological material investigated. Satisfactory separation of the tropane alkaloids mentioned was obtained at temperatures above 210°C on the SE-30 column. 

Dimitrov K, Metcheva D, Alexandrova S, Saboni A, Boyadzhiev L. Recovery of tropane alkaloids from Deadly Nightshade. I. A hybrid process of solid-liquid extraction and liquid membrane purification. Bulgarian Chem Commun 2006 38 231-236. 

The tertiary tropane alkaloids can be extracted from the plant material in the form of salt with acidic aqueous solutions or as bases at pH > 8-9 with organic solvents such as methanol, ethanol, chloroform, etc. Sample purification procedures for tropane alkaloids before chromatographic analyses are based usually on liquid-liquid extraction (LLE) or solid-phase extraction (SPE). The choice of solvents depends on the solubility Ka and pk h) in water of the target alkaloids. For quantitative analyses, exhaustive extraction or the use of suitable internal standard should be ensured. 

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