Fast GC-TOFMS with Select-eV Ionisation for High-Throughput Screening of Environmental Contaminants

Oral Presentation

Prepared by N. Watson1, L. McGregor2, C. Widdowson2
1 - Markes International, 11126-D Kenwood Road, Cincinnati, OH, 45242, United States
2 - Markes International, Gwaun Elai Mediscience Campus, Llantrisant, RCT, CF72 8XL, United Kingdom


Contact Information: nwatson@markes.com; 513-488-6161


ABSTRACT

The introduction of recent environmental regulations, such as the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA, or ‘Superfund’) has encouraged the development of precise and robust analytical systems for identifying pollutants and linking them to their sources. However, the sheer number of toxic compounds that may require monitoring at any given time makes this a challenging prospect.

Conventional quadrupole GC-MS methods often employ selective ion monitoring (SIM) for trace-level detection of target compounds. However, this protocol prevents retrospective searching of data for the latest contaminants of emerging concern. The use of time-of-flight mass spectrometry (TOFMS) can overcome this issue by providing highly sensitive detection whilst acquiring full range mass spectra, to allow both target and unknown identification in a single, rapid analysis.

Nevertheless, trace-level identification may become complicated for compounds which exhibit weak molecular ions and extreme fragmentation, e.g. the ‘drin’-type pesticides, such as dieldrin and endrin. Select-eV ion source technology aims to combat this problem by allowing both hard and soft electron ionisation with no inherent loss in sensitivity. Select-eV provides enhanced molecular ions whilst retaining structurally-significant fragment ions, delivering both confident compound identification and lower limits of detection.

This work demonstrates the use of fast GC-TOFMS with Select-eV ionisation for accurate identification of a suite of ultra-trace level environmental contaminants.