Moderne Methoden der Pflanzenanalyse / Modern Methods of Plant Analysis
des. 2012 · Springer Science & Business Media
5,0star
1 anmeldelsereport
E-bok
762
Sider
reportVurderinger og anmeldelser blir ikke kontrollert Finn ut mer
Om denne e-boken
If, following the solvent extraction of a hydrocarbon from a plant, it is not known whether it is one or the other, a method of distinguishing the two is described by HENDRICKS, WILDMAN and JONES (1946). The technique involves the infra-red absorption spectra of the two isomers. At about 12 mp. the relative absorption coefficient of rubber is 42% greater than for gutta. ScHLESINGER and LEPER (1951) describe two procedures for separation of the rubber and gutta hydrocarbons from large quantities of crude chicle. In one, the chicle is extracted with benzene which dissolves both isomers. An excess absolute ethyl acetate is added and the mixture stored at 5° C overnight. The gutta precipitates out and the rubber remains in solution. The other method is as follows: (1) Ten grams of chicle are extracted with acetone for 24 hours in a Soxhlet extraction apparatus. (2) The insoluble material in the thimble is allowed to .. it dry, then immersed in 150 ml. of cold Skellysolve B in a refrigerator at 10° C and· allowed to stand for 48 hours with occasional agitation. (3) The thimble is then removed from the solvent and the enclosed residue washed several times with fresh, cold Skellysolve B. (4) An excess of acetone and a few drops of a concentrated aqueous solution of sodium iodide are added to the combined Skellysolve B extract and washings and allowed to stand overnight in a refrigerator.
Vurderinger og anmeldelser
5,0
1 anmeldelse
Vurder denne e-boken
Fortell oss hva du mener.
Hvordan lese innhold
Smarttelefoner og nettbrett
Installer Google Play Bøker-appen for Android og iPad/iPhone. Den synkroniseres automatisk med kontoen din og lar deg lese både med og uten nett – uansett hvor du er.
Datamaskiner
Du kan lytte til lydbøker du har kjøpt på Google Play, i nettleseren på datamaskinen din.
Lesebrett og andre enheter
For å lese på lesebrett som Kobo eReader må du laste ned en fil og overføre den til enheten din. Følg den detaljerte veiledningen i brukerstøtten for å overføre filene til støttede lesebrett.
