Analysis of Pesticide Residues in JonaGold Apples Using QuEChERS Approach and Comprehensive Two-Dimensional Gas Chromatography Time-of-Flight Mass Spectrometry (GCxGC-TOFMS)
Poster Jun 14, 2011
Joe Binkley, John R Heim and Doug Staples
Time-of-Flight Mass Spectrometry (TOFMS) provides a valuable solution through its ability to acquire full range mass spectra without sacrificing speed or sensitivity. There is no need for SIM to enhance detection limits. TOFMS offers fast acquisition speeds (up to 500 full mass range spectra/second) and spectral continuity, allowing optimum performance of the Mass Spectral Deconvolution algorithms ® incorporated into the LECO ChromaTOF software, which add an extra dimension of qualitative analysis to complex samples. The fast acquisition rates of TOFMS also support the use of comprehensive two-dimensional gas chromatography (GCxGC). GCxGC provides increased peak capacity and resolution, which is very beneficial when analyzing samples with complex matrices. In addition, GCxGC provides an increase in analyte detectability through the cryo-focusing effects of thermal modulation. The need for a fast detector is due to the extremely narrow peak widths typical of thermally modulated GCxGC peaks, usually on the order of 50 to 100 ms wide. When MS is combined with GCxGC, only TOF can achieve the necessary acquisition rates.
This poster shows the successful use of comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GCxGC-TOFMS) for effective screening and quantitation of pesticides in apples. JonaGold apples from Southwest Michigan were analyzed for potential pesticide residues following preparation by a QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) extraction approach. A cryogen-free thermal modulator was utilized for these analyses.