A hybrid HRGC/MS/MS method for the characterization of tetrachlorinated-p-dioxins in environmental samples

Abstract

A new instrumental method for the characterization of the analyte 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) by selected reaction monitoring (SRM) analysis is investigated. The method uses high-resolution gas chromatography coupled to a hybrid tandem mass spectrometer. The technique was evaluated with regard to four performance parameters: sensitivity, linearity, repeatability and selectivity. The method compares favorably with the traditional selected ion monitoring HRGC/HRMS technique, and the selectivity of the new method is shown to surpass the established HRGC/HRMS method. This new method could allow the characterization of samples that have undergone less rigorous cleanup than is now possible by the traditional mass spectrometric methods. The presence of TCDDs in a real sample was confirmed by using the new HRGC/(hybrid)MS/MS SRM method, which was not possible by using HRGC/HRMS analysis.

Current use of high-resolution mass spectrometry in the environmental sciences

“…An example of this is the separation of the molecular ion of 2,3,7,8-tetrachlorodibenzop-dioxin (TCDD) from commonly encountered interferences. Resolution of 12,500 is required to resolve TCDD from interfering ions that originate from the fragmentation of heptachlorinated biphenyl isomers, whereas a resolution of almost 18,000 is needed to separate TCDD from chlorinated xanthenes [26]. Although modern double-focusing mass spectrometers are capable of achieving this resolution, there is, as a consequence, loss of instrument sensitivity when resolution is increased.…”

A novel high-capacity ion trap-quadrupole tandem mass spectrometer

“…Currently available instruments [17][18][19][20][21][22][23][24][25][26] are very inefficient for such linked-scan analyses (Fig. 1A).…”

“…Currently, the only technique that approximates such an analysis is the linked-scan mode available in triple quadrupole, quadrupole-quadrupole time-of-flight, ion trap, and sector instruments [17][18][19][20][21][22][23][24][25][26]32]. However, instead of producing complete MS/MS fragmentation spectra of every species in the m/z range of the instrument, the technique produces only spectra of those precursor ions that generate a particular ion product or a particular neutral loss.…”

Establishment of a fluorescence resonance energy transfer-based bioassay for detecting dioxin-like compounds

“…To the present, utilization of high-resolution gas chromatography with high-resolution mass spectrometry (HRGC/ MS) is recognized as the most efficient way for determining dioxin compounds including TCDD [11]. However, this detection system is very expensive, and the procedures are not easy to carry out.…”