Solventcinnamon

IsolationofCinnamaldehydefromCinnamonIntroductionInthisexperimentyouwillisolatecinnamaldehydefromcinnamon.
Commercialcinnamonconsistsofdried,groundbarkfromthecinnamontree,andcontainsabout2%cinnamaldehyde,whichisresponsibleforitsdistinctflavorandodor.
Theisolationwillbeaccomplishedbysteamdistillation.
Thismeansthatthesolidcinnamonwillbeboiledinwater,andthesteamwillbecondensedandcollected.
Sincecinnamaldehydeissolubleinsteam(butnotinwater),itwillbecarriedupwiththedistillateandformafinelydistributedemulsion,whichwillappearmilkyuponcooling.
Manyotheressentialoilscanbeisolatedinthisway–anisolefromanise,camphenefromnutmeg,carvonefromcarawayandspearmint,cuminaldehydefromcumin,eugenolfromcloves,safrolefromsassafras,andlimonenefromcitruspeel.
Pleaseread"PurifyingaLiquidbyDistillation"tolearnhowanordinarydistillationisrun.
Alsoread"ExtractingandWashing,""DryinganOrganicSolvent,"and"EvaporatinganOrganicSolvent"beforecomingtolab.
Writeanintroductioninyourlabmanual.
ProcedureSteamdistillationofthecinnamon:Obtaina100mlErlenmeyerflaskwitha14/20groundglassjointfromtheinstructor.
Add15mlofdistilledwater,2dropsofTritonX-100(asurfactantwhichreducesfoaming),2.
0gofcinnamon,andalongstirbar.
AttachaHickmanstilltotheflask,thentopitwitharefluxcondenser.
Attachtherefluxcondensertothewaterhosesandturnonthewater.
Insulatethetopoftheflaskbelowtheneckofthestillwithaluminumfoil.
Turnonthestirrerandbegintoheatthecinnamonmixtureslowlyuntilitbeginstoboil.
Ifitfoamsupintothestill,youareheatingtooquickly–ifthefoamgetsintothelipofthestill,you'llhavetotakeitoffandcleanitbeforecontinuing.
Removethedistillatewithapipetasitcollectsandplaceitinabeakerorflask.
If,aftercollectingsomedistillate,thestillbeginstolookdry,addupto1mlofwater(nomore!
).
Trynottobakethecinnamonontotheglassware,asitishardtocleanout.
Youshouldcollectabout5mlofdistillate;onceitnolongerturnsmilkyoncooling,mostofthecinnamaldehydehasbeenremoved.
Isolationofthecinnamaldehydefromthedistillate:Placeasepfunnelontheclampandputabeakerunderneathit.
Aftermakingsurethestopcockisclosed,transferthedistillatetothesepfunnel.
Extractitbyaddingabout5-10mlofdichloromethane,shaking,allowingittoseparate,anddrainingoffthedichloromethane.
Repeattwomoretimes,combiningallofthedichloromethanelayersthatyoudrainoff.
Don'tthrowawayanythinguntilyouaresureyouhavewhatyouwant!
Drythedichloromethanesolutionbyaddingsodiumsulfateuntilitisfreeflowing.
Transferthesolutiontoatared(preweighed)roundbottomflaskandrinsethesolidsodiumsulfatewithalittlemoredichloromethane.
Evaporatethesolutionontherotovap.
Observetheproductthatyouhaveobtainedandrecordyourobservation.
Authenticcinnamaldehydeisaclear,slightlyyellowliquidwithastrongodorofcinnamon.
Whentheflaskiscool,obtainthemassofthecinnamonoilthatyouhaveextracted.
Calculatethe%recoveryofcinnamaldehyde.
Discusstheodor,appearance,mass,andpercentrecoveryofthecinnamaldehydeinyourconclusion.
Questions1)Cinnamaldehydecannotbedistilleddirectlybecauseitdecomposesbeforeitreachesaboilingpoint(about248oC).
Howdoessteamdistillationavoidthisdifficulty2)Whatwouldhappenifyouattachedtherefluxcondensertotheflaskfirst,thenputtheHickmanstillontop3)Whydoesthedistillateappearmilky4)Whatwouldhappenifyouevaporatedthedichloromethanesolutionwithoutdryingitfirst5)Whywouldyouneverexpecttogeta100%recoveryofcinnamaldehyde