AOAC 30.1.23A AOAC Official Method 995.13

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1、30.1.23A(l)Waterbath.—Maintaining98±2°C.AOACOfficialMethod995.13(m)Liquidchromatograph(LC).—Metal-free,compatiblewithCarbohydratesinSoluble(Instant)Coffee300mMNaOH.Operatingconditions:mobilephase,isocratic(seeAnion-ExchangeChromatographicMethodTable995.13formobilephaseconditions);co

2、lumntemperature,withPulsedAmperometricDetectionambient;flowrate,1.0mL/min;post-columnsolvent,300mMFirstAction1995NaOHat0.6mL/min;detectorsettings,optimumparametersaspro-videdbymanufacturer.Usewithcomputingintegrator.(Applicablefordeterminationoffreeandtotalcarbohydrates[ex-cepttotal

3、fructose,whichisdegraded]insoluble[instant]coffee.)(n)LCcolumn.—250´4mmid;packedwithpolystyrenedivinylbenzenesubstrate(10mmdiameter)agglomeratedwithSeeTables995.13A–Jfortheresultsoftheinterlaboratorystudymicrobeadquaternaryaminefunctionalizedlatex(350nmdiame-supportingtheacceptanceo

4、fthemethod.ter);5%cross-linked.(o)Pulsedamperometricdetector.—Withgoldelectrode.FillA.Principlereferencecellwith300mMNaOH.SelectthedetectorrangetoavoidFreecarbohydrates.—CoffeeisdissolvedinH2O.Solutionisfil-saturationofthemajorpeakinchromatogram.teredthroughC18disposablecartridge,an

5、dthenthrough0.2mm(p)Guardcolumn.—50´4mmid,packedwiththesamemate-membranefilter.FilteredsolutionisinjectedontoLCsystem.Car-rialasanalyticalcolumn,(n).bohydratesareseparatedonpellicularanion-exchangecolumnand(q)Post-columnsolventdeliverysystem.—Compatiblewithmeasuredbypulsedamperometr

6、icdetector.300mMNaOH.Totalcarbohydrates.—Coffeeishydrolyzedwith1MHCl.Solu-tionisfilteredandthenpassedthroughcation-exchangedisposableC.ReagentscartridgeintheAgformtoneutralizesolutionandtoeliminatetheClUse18MW×cmdemineralizedH2Othroughout.anionpriortoinjectionontoLCsystem.(a)Sodiumh

7、ydroxide.—50%(w/w)aqueoussolution,contain-B.ApparatusingminimumamountofNa2CO3andHg.Donotshakeorstirsolu-(a)Balance.—Analytical,weighingto0.1mg.tionbeforeuse.(b)Flasks.—250mLround-bottom.(b)Hydrochloricacidsolution.—1.00Mstandardvolumetricso-(c)Volumetricflasks.—100and1000mL.lution(8

8、3.3mLHCl/L).(d)Pipe