GC-MS/MS Analysis of Pesticide Residue in Green Tea Extracted by QuEChERS with Acetonitrile as Final Solvent
Poster Jul 30, 2014
Cojocariu C., Morgan P., Silcock P., Godula M
This poster describes the analysis of several challenging pesticides from green tea samples using GC MS/MS and acetonitrile as final extraction solvent. The compounds analysed are representatives of various classes of pesticides, such as carboxamids, OC, OP, pyrethriods, aromatic, phenylamides. QuEChERS (Quick, Easy, Cheap, Effective, Rugged, Safe) is a well known approach used for the extraction and clean-up of pesticide residue in various matrices. Typically, the final extract ends up with the pesticides in acetonitrile. Direct injection of acetonitrile extracts is problematic in GC-MS compared to LC-MS because of poor focusing of chromatographic peaks due to the high polarity of acetonitrile, limitations on injection volumes due to the high expansion coefficient of acetonitrile and contamination of the system by matrix co-extractives .
Here we present a simple and robust analytical method which employs low volume splitless injections of acetonitrile sample extracts and the selectivity of the Thermo Scientific™ TSQ™ 8000 triple quadrupole GC-MS/MS instrument. With this approach, pesticide target reporting limits of <0.01 mg/kg can be easily achieved. This also overcomes the problems associated with the thermal expansion of acetonitrile and reduces the amount of matrix injected.
Fundamentals and Comparisons for Organic Sample Extract EvaporationPoster
Sample preparation is a key step in the analysis process
Parameters for evaporation and their impact on analysis have been discussed
Improvements in matching the sample to the evaporation device characteristics can help reduce variability and improve recovery
Examples for choosing a system based on sample volume, types of analytes, sample load, and initial investment considerations
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