Application of capillary isotachophoresis for fruit juice authentication

A method using capillary isotachophoresis (ITP) was developed and applied f or the determination of the anionic profile of orange juices with the aim t o obtain some useful information on the authenticity or adulteration of imp orted and native beverage products. An EA 100 electrophoretic analyser (Vil la-LABECO, Slovak Republic) was used for capillary isotachophoretic determi nation of anions in tested samples. More systems of leading and terminating electrolytes were used. Detection conductivity and UV detection at 254 nm were used. Sample injection volume was 30 mul. These systems allow one to d eterminate inorganic anions? organic acids and some additives - adulterants in anionic forms in orange juices. By capillary isotachophoretic determina tion the lengths or areas of characteristic zones were established and comp ared to authentic orange juices of different species and origin and with RS K reference values (Code of Practice). Special emphasis was placed on D-iso citric acid ITP determination as a reliable fruit juice authentication mark er. The presented multicomponent analysis of orange juice authenticity acco rding to ITP anionic profiles obtained by capillary isotachophoresis presen ts an alternative information source necessary for deciding about authentic ity of the products. (C) 2001 Elsevier Science B.V. All rights reserved.