Browsing by Subject "GC-MS/FID"

The literature review focused on quinoa saponins, on their extraction, isolation and chromatographic analysis. The aim of this study was to develop a quantitative and qualitative analysis method for saponins in quinoa. Gas chromatograph (GC) was used for separation. Saponin aglycones were indentified by mass spectrometry (MS) and quantified by flame ionization detector (FID). Sample pretreatment included extraction of fat soluble compounds and saponins by accelerated solvent extraction (Dionex ASE). Saponin aglycones liberated by acid hydrolysis followed by liquid-liquid extraction. Aglycones were derivatised to silylethers and analysed with GC-MS/FID. Finally this method was used to analyse saponins in washed and pearled quinoa seeds. Method evaluation included repeatability test (4 separate days, total n = 14). Average, standard deviation, relative standard deviation and Horrat(r) - value were calculated for the results. Method realability was evaluated by recovery test. Known amount of saponin was added to flour samples (n = 3). Additions responded 6, 4 µg, 12, 8 µg and 32 µg hederagenin aglycone. Four saponin aglycones, oleanolic acid (ole), hederagenin (hed), serjanic acid (ser) and phytolaccagenic acid (phy), were successfully identified in all samples by method prescribed. Method was repeatabale for ole and ser quantition but not for hed and phy. Satisfactory recovery, 80 %, was achieved on 32 µg addition level. Recoveries for 6, 4 µg and 12, 3 µg addition levels were 76 and 66 %. Results could be explained by aglycones pH dependent solubility combined to inaccurate pH adjustment after hydrolysis. In the future neutralization step should be revaluated. Washing reduced saponins 20–58 % and pearling reduced 58 % saponins in quinoa seeds. However pearling caused loss of protein from 12, 3 % to 5, 8 %.