Liesl Krone presents her award-winning research.
Restek is pleased to congratulate Liesl Krone, a student at Crossland Ninth Grade Center in Granbury Texas, whose science fair project recently advanced to the ExxonMobil State Science and Engineering Fair (EMTSEF) after placing 1st at the Fort Worth Regional Science and Engineering Fair. Her project entitled “Stay Home or Go Global—Local Versus Imported Fruit” also won an honorable mention for Best in Show during regional competition, garnering her an invitation to present her work at the Intel® International Science and Engineering Fair® (Intel ISEF).
Since food safety standards and the use of pesticides differ around the world, Liesl was curious to know whether locally grown fruits would be freer of pesticides than their imported counterparts. To find out, Liesl paired a QuEChERS sample extraction and cleanup procedure with LC-MS/MS analysis and evaluated pesticide residue levels across a wide range of samples that included organic and non-organic, as well as locally grown and imported berries and pome fruits.
After analyzing 13 samples for approximately 180 compounds, Liesl found that pesticide levels were low overall and that the presence of pesticides did not correspond to country of origin. Interestingly, the sample that contained the most pesticides was an organic pear from the U.S. This led her to conclude that organic labeling does not always guarantee a fruit is truly organic or free of pesticides. As Liesl puts it, “The issue seems to be whether a fruit is truly organic, and it doesn’t matter so much that the fruit is imported.”
This project was made possible by Analytical Food Labs, AB SCIEX, and Restek Corporation.
Congratulations, Liesl, and good luck at Intel ISEF and the state competition!
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Author(s): Michelle Misselwitz, Jack Cochran, Julie Kowalski
Published By: Chromatography Techniques
Year of Publication: 2014
Abstract: Pesticides are used heavily on tobacco in order to increase crop production value; however, limited regulation creates the potential for high levels of pesticide residues to remain on finished tobacco products. Analysis of pesticides on tobacco is extremely challenging due the natural complexity of this botanical matrix. The work detailed here used the QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) approach for extraction and GCxGC-TOFMS for analysis. In addition, the experimental design compared dispersive solid phase extraction (dSPE) and cartridge solid phase extraction (cSPE) cleanup approaches. The wide range of pesticides chosen for this study covered many of the 37 pesticides that have been approved by the U.S. EPA for use on tobacco. The combination of QuEChERS, GCxGC-TOFMS, and dispersive solid phase extraction cleanup allowed easy and accurate analysis and separation of target pesticide residues from the tobacco matrix.