Pittcon 2013-Presentation #3

Wednesday, March 20, 2013 3:55 pm - 3:55 pm EDT (GMT -04:00)


Silica Based Ionic Liquids for 96-Blade System for Extraction of Polar Compounds from Complex Matrixes

Presented by Fatemeh Mousavi

1-Vinyl-3-octadecylimidazolium Bromide ionic liquid [C18VIm]Br was prepared and used for the modification of mercaptopropyl-functionalized silica (Si-MPS) through surface radical chain-transfer addition. The synthesized compound was characterized by infrared spectroscopy, thermogravimetric analysis, and solid-state 13C and 29Si nuclear magnetic resonance spectroscopy. The synthesized ionic liquid-modified silica (SiImBr) was used as the extraction phase for an automated 96-blade solid phase microextraction (SPME) system with thin-film geometry. The new proposed extraction phase was applied as the extraction phase for extraction of aminoacids from grape pulp. LC-MS-MS method was developed for separation of model compounds. Extraction efficiency, inter- and intra-blade reproducibility, linearity, limit of detection and quantitation, and matrix effect were evaluated. SPME method development showed that 90 min extraction time was required for equilibrium extraction of all five analytes, and desorption in acetonitrile/water 50:50 (v/v) (minimum 60 min) provided the best recovery and lowest carry over. Inter-blade and intra-blade reproducibility were respectively in the range of 5-13 and 3-10% RSD (relative standard deviation) for all model compounds. Limits of detection and quantitation of the proposed SPME-LC-MS/MS system for analysis of analytes were found in the range of 0.1-1.0 and 0.5-3.0 μg/L, respectively. Standard addition calibration was applied for quantitative analysis of aminoacids from grape juice and the results were validated with Liquid liquid extraction (LLE) technique.