alexys™ analyzers - SiSW >> Science Instruments and Software

THE FINEST LC-EC APPLICATIONS FORFOOD & BEVERAGE ANALYSISEVER PROCESSEDDocumentationSupportInvitation to Antec’s support site• 24/7 access to Antec’s knowledge base• application notes, manuals, tutorials• software updates & free trials220_002 #03FOOD & BEVERAGEAPPLICATION NOTEPage : 1/10Customer satisfaction is and has always been our firstpriority. To support our customers we have created asupport website which is now at your disposal.Our knowledgebase contains all the relevant tips and tricksfrom years of experience in LC-ECD.It offers a 24/7 support, always available when needed.ANALYSIS OF CARBOHYDRATESANION-EXCHANGE CHROMATOGRAPHY ANDPULSED AMPEROMETRIC DETECTIONBisphenol ACatechinsFlavonoids and phenolsPhenolsAntioxidantsPolyphenolsResveratrolEpicatechinQuercetinother polyphenolsCarbohydratesIodideVitamins A, C, D, E, and KQ10ubiquinolsINTRODUCTIONCarbohydrates not only providethe most easily accessibleenergy source for ourbody, they also play an importantrole in many physiologicalprocesses. Some examplesof these processes areintercellular recognition,infection processes, andcertain types of cancer. Thedetermination of carbohydratesis of interest to thefood industry and many fieldsin life sciences.Analytes of interest includesimple mono- or disaccharides(such as glucose andsucrose), oligosaccharides(Maltodextrin), polysaccharides(starch, cellulose) andglycoproteins.Numerous analytical techniquesfor carbohydrate analysishave been developedover the years [6]. The polar,non-volatile, water-solublecarbohydrates are not easilyre-solved. Also detection ofthese non-chromophoriccompounds is difficult. Carbohydrateshardly have anyUV absorption and thereforeeither refractive index (RI) orelectrochemical detection(EC) is used for analysis.• Carbohydrates in food industry and fields in life sciences• Analytes of simple mono- or disaccharides• Analytes of oligosaccharides (Maltodextrin)• Analytes of polysaccharides (starch, cellulose)• Analytes of glycoproteinsDue to the poor detection limits of RI, EC has become the preferreddetection method in trace analysis. Anion-ExchangeChromatography at high pH in combination with pulsedamperometric detection (PAD) is nowadays the most sensitiveanalytical method available for carbohydrate analysis [1,2].In this application note we present a simple and sensitive systemsolution for the determination of sugars and oligosaccharides infood products based on the ALEXYS 100 'Carbohydrate' systems.MethodAnion Exchange Chromatography - Under alkaline conditions (pH> 12) carbohydrates can be separated by means of Anion-Exchange Chromatography. Carbohydrates are weak acids withpKa values ranging between 12 and 14. At high pH they will beeither completely or partially ionised depending on their pKavalue. Due to the extreme alkaline conditions only polymericanion-exchange columns are suitable for carbohydrate separation.The retention time of carbohydrates is inversely correlated withpKa value and increases significantly with molecular weight. Theelution order of carbohydrates on such anion-exchange columnsis usually as follows: sugar alcohols elute first, followed by mono-,di-, tri-, and higher oligosaccharides.CarbohydratesAntec Leyden B.V. - Industrieweg 12 - 2382 NV - Zoeterwoude - The Netherlands - info@myantec.com - www.myantec.comAntec (USA) - Suite 110 - 7502 Connelley Drive - Hanover MD 21076 - USA - info.usa@myantec.com - www.myantec.comRegister today at www.myantec.comgo to support and have free access !Proven analyzers to guarantee your performance®37