Stable Isotope Dilution Analysis of Organic Pollutants Using LC-MS/MS (QqQ) and Isotope Pattern Deconvolution
Poster Nov 25, 2010
A. Castillo, E. Gracia-Lor, A.F. Roig-Navarro, P. Rodriguez-Gonzalez, J.V. Sancho and J.I. García Alonso
For quantitative purposes the main limitation is the ion suppression caused by matrix components when using an electrospray ion source. The use of stable isotopically labelled compounds as internal standards (deuterated or 13C-labelled) is normally the preferred strategy to correct for such problem. To this end, a calibration graph is required using the natural and labelled intensity ratio of the more abundant ions.
Isotope Pattern Deconvolution (IPD) appears as a promising alternative to improve the determination of organic pollutants, since it allows spectral overlap between natural and labelled clusters as well as not requiring an isotope dilution calibration graph.
The poster highlights an Isotope Dilution AnaIysis methodology based on the Isotope Pattern Deconvolution approach, which has been applied for the first time to LC-ESI-MS/MS (QqQ) in SRM mode.
Using Elemental Analysis For Discrimination Of Pinot Noir Wines From Six Different Districts In An AvaPoster
The determination of geographical origin of wine is gaining increased interest by researchers and federal agencies around the world, partially due to increased fraud with regards to place of origin labelling. For wine, multi-elemental profiling of macro, micro, and trace elements has been proposed for determination of authenticity. Commercial wines from different wineries in 5 different neighborhoods within one AVA show characteristic elemental fingerprints. Macro, micro and trace elements as well as elemental ratios contribute to the observed separation, indicating the involvement of multiple factors and underlying mechanisms, including location and soil composition, elemental uptake by vine and rootstock, viticulture and nutrient management, water sources, and small differences in the different wineries.READ MORE
Fast arsenic speciation analysis of wines and rice with LC-ICP-QQQPoster
This method was designed in response to recent and proposed food standards, both international and national, that limit inorganic arsenic rather than total, organic, or individual arsenic species such as arsenite (AsIII) and arsenate (AsV). Analysis time is 10x faster than the current FDA regulatory method, increasing sample throughput, avoided spectral interferences and dramatically increased sensitivity. Validation data from two laboratories demonstrate the method’s accuracy and reproducibility of both wine and rice matrices in a single analytical batch.READ MORE
Elemental profiles of whiskies allow differentiation by type and region by inductively coupled plasma –optical emission spectroscopy (ICP-OES)Poster
The analysis of the elemental composition of whiskies provides a host of important information including sample origin and understanding how different whiskey styles are caused by processing equipment and raw materials. Preliminary data analysis of the whiskies showed that element compositions could possibly be used to differentiate samples based on age, type, and region.READ MORE