Assessing Beyond LC-MS-MS Using Q Exactive HRAM for Routine EPA Drinking Water Methods

Oral Presentation

Prepared by A. Haghani, A. Eaton, E. Wilson, F. Haley
EEA, 750 Royal Oaks Suit 100, Monrovia, CA, 91016, United States


Contact Information: [email protected]; 626-386-1100


ABSTRACT

Within the last decade Liquid Chromatography Tandem Mass Spectrometry’s LC-MS-MS sensitivity has increased by a factor of ten making it one of the most sensitive techniques for quantitation purposes of targeted compounds. The ease of use for detecting more polar compounds makes the LC-MS-MS the gold standard for analysis of emerging contaminants in environmental samples. However, with development of new software’s, firmware’s, and hardware’s some of High Resolution Accurate Mass spectrometry’s HRAM sensitivity rivals to mid to high end LC-MS/MS, in addition to much improvement in its quantitation capabilities compared to its predecessors.

This opens a great opportunity not only for using HRAM for routine quantitation of targeted compounds at low levels rival to LC-MS/MS’s but also expand looking into discovery and identification of site specific emerging contaminants for which there are not as yet official EPA methods available.

For this presentation we assess different quantitation capabilities of a Q Exactive, hybrid quadrupole Mass Spectrometry HRAM, against well written standardized EPA methods for drinking water. Comparing Full-Scan, tSIM (targeted SIM), and their data dependent fragmentation ddMS2 data to TSQ Vantage LC-MS-MS performances , and discuss pro and cons of each technique after analyzing methods along with the prescribed Initial Demonstration Capability (IDOC) and a subset of real samples.
The two methods chosen for this assessment are:

1. Method EPA 537: DETERMINATION OF SELECTED PERFLUORINATED ALKYL ACIDS IN DRINKING WATER BY SOLID PHASE EXTRACTION
AND LIQUID CHROMATOGRAPHY/TANDEM MASS SPECTROMETRY ( LC/MS/MS), and

2. Method EPA 539: DETERMINATION OF HORMONES IN DRINKING WATER BY SOLID PHASE EXTRACTION (SPE) AND LIQUID CHROMATOGRAPHY ELECTROSPRAY IONIZATION TANDEM MASS SPECTROMETRY (LC-ESI-MS/MS)

Both methods are currently being used extensively in the EPA Unregulated Contaminant Rule 3 (UCMR 3) program, so assessing performance of alternative instruments is valuable.