Determination of polychlorinated dibenzo-p-dioxins and furans in food samples by gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS) and comparison with gas chromatography-high resolution mass spectrometry (GC-HRMS)

Although gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS) has been applied to the determination of polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) in various food samples, there is insufficient evidence to evaluate its equivalence with gas chromatography-high resolution mass spectrometry (HRMS). In the present study, two GC-MS/MS instruments with different ion sources (advanced electron ionization [EH and atmospheric pressure chemical ionization [APCI]) were evaluated for detecting trace levels of PCDD/Fs in various foods. GC-EI-MS/MS and GC-APCI-MS/MS showed good linear relationships for 17 PCDD/Fs (0.01-200 ng/mL, R-2 > 0.999), and the relative standard deviations of the relative response factors were 3-18%. The limit of quantitation range of the PCDD/Fs was 0.005-0.101 ng/mL with GC-APCI-MS/MS and 0.006-0.201 ng/mL with GC-EI-MS/MS. The capabilities of the GC-MS/MS methods were evaluated for determination of PCDD/Fs in reference materials and real food samples. Statistical analyses showed that the toxic equivalents (TEQs) were comparable to those obtained with GC-HRMS, and the methods had good sensitivity, repeatability, and reproducibility. No difference was found between the results from the GC-MS/MS techniques and GC-HRMS when the PCDD/Fs concentrations were greater than 10(-2) pg/g. The results suggest that when the total TEQ is greater than 0.57 pg TEQ/g (lipid weight) or 0.052 pg TEQ/g (wet weight), GC-MS/MS techniques could be used as a complementary approach to GC-HRMS. Both GC-EI-MS/MS and GC-APCI-MS/MS have similar sensitivity, selectivity, and stability to HRMS and could be used as confirmation methods for the analysis of trace PCDD/Fs in animal foods.

Automated summary

The present study evaluated two GC-MS/MS instruments with different ion sources for detecting trace levels of PCDD/Fs in various foods. The GC-MS/MS methods showed good sensitivity, repeatability, and reproducibility, and the results were comparable to those obtained with GC-HRMS.