Xaiv qhov tsim nyog extraction hnyav yog qhov tseem ceeb kom ua tiav kev sib cais thiab ntxuav cov tebchaw.
Qhov tseeb xaiv ntawmrho tawmCov kuab tshuaj yuav tsum ua raws li cov ntsiab lus hauv qab no:
(1) Cov kuab tshuaj rho tawm yog insoluble lossis yuav luag insoluble hauv dej;
(2) Cov kuab tshuaj tsis ua rau cov tshuaj tiv thaiv tsis tuaj yeem nrog cov khoom sib xyaw;
(3) Lub solubility ntawm cov khoom rho tawm hauv cov kuab tshuaj yog qhov loj, thaum lub solubility ntawm impurities thiab lwm yam hauv cov kuab tshuaj yog me me;
(4) Lub boiling point ntawm cov kuab tshuaj extraction yuav tsum tsis txhob siab dhau, thiab nws yuav tau yooj yim tshem tawm ntawm lub solute los ntawm distillation thiab lwm txoj kev.
Tsis tas li ntawd, cov kuab tshuaj muaj kev ruaj ntseg zoo, tus nqi qis, tsis muaj tshuaj lom, tsim nyog tus txheeb ze ntom ntom, thiab yooj yim ntawm kev ua haujlwm kuj tseem yuav tsum tau xav txog. Kev xaiv ntawm cov kuab tshuaj extraction yog nyob ntawm qhov xwm ntawm cov extract. Feem ntau hais lus, cov khoom uas nyuaj rau yaj hauv dej yog muab rho tawm nrog roj av ether, thiab lwm yam .; cov uas yog soluble ntau yog muab rho tawm nrog diethyl ether los yog toluene; Cov khoom uas yooj yim soluble hauv dej yog muab rho tawm nrog ethyl acetate los yog lwm yam kuab tshuaj zoo sib xws. Piv txwv li, siv ether los rho tawm oxalic acid los ntawm dej tsis zoo. Yog tias koj siv ethyl acetate hloov, cov nyhuv yuav zoo dua.
Qhov tseeb, cov kuab tshuaj zoo tshaj plaws yog qhov nyuaj nrhiav. Tsuav nws ua tau raws li cov kev cai tseem ceeb, nws tuaj yeem siv tau txawm tias muaj qee qhov tsis txaus. Feem ntau siv cov kuab tshuaj muaj xws li: ether, petroleum ether, pentane, hexane, carbon tetrachloride, chloroform, dichloromethane, dichloroethane, toluene, ethyl acetate, cawv, thiab lwm yam.