Determination of Isomaltooligosaccharides in Yoghurts by Using HPLC-ELSD

A rapid and simple analytical method for the determination of 9 isomaltooligosaccharides (IMO) species in yoghurts was developed using dispersive solid phase extraction (dSPE) clean-up technic and high performance liquid chromatography with evaporative light-scattering detector (HPLC-ELSD). In this study, 9 IMO were extracted from samples simply with chemical reagent using ISO22662 IDF198 method and additional dSPE clean-up. The optimum instrument conditions for the determination were used carbohydrate ES 5 mu column with gradient elution of water and acetonitrile and ELS detector. The linearity of this method was expressed as the correlation coefficient (r(2)), the results of IMO 9 species were shown in 0.9999. LOD and LOQ were respectively 7.9-22.1 mg/kg, 25.9-72.8 mg/kg. The accuracy of intra- and inter-day measurements were in the range from 84.3 +/- 4.5 to 104.9 +/- 6.5%, and the preceision of the intra- and inter-day measurements were in the range from 0.8 to 7.7%. The recoveries were from 84.3 +/- 4.5 to 104.9 +/- 6.5%. The determination results of IMO 9 species for the 9 yoghurts circulated in the market were in the range from 0.317 +/- 0.007 to 1.624 +/- 0.050 g/100 g. The newly developed method is appropriate for the determination of MO in yoghurts, is a rapid and simple method with excellent resolution in compared with previous method.