Application of a High-Resolution Quadrupole/Orbital Trapping Mass Spectrometer Coupled to a Gas Chromatograph for the Determination of Persistent Organic Pollutants in Cow’s and Human Milk

Abstract

A quadrupole/orbital trapping mass spectrometer or Q-Exactive (QE) interfaced with a gas chromatograph (GC) was optimized for measuring polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/Fs), and polychlorinated biphenyls (PCBs) in foods. Figures of merit include (1) an instrument detection limit (IDL) for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) of 9 femtograms (fg), (2) quantitative mass resolution from PCDD interferences (e.g., PCBs, methoxy-PCBs DDTs, polychlorodibenzylphenyl ethers, polychloroxanthenes, methyl-polychlorodibenzofuran, and polychlorodibenzothiophenes), and (3) mass accuracy <1 ppm at the IDL. The QE measured the concentrations of PCDD/Fs and PCBs in whole cow’s milk with no known source of contamination (e.g., TCDD 33 fg/g fat). A National Institute of Standards and Technology (NIST) unfortified human milk standard reference material (SRM) 1953 was measured determining 27 PCDD/F and PCB congeners with an average difference of 7.6% from the certified results. The QE-GC is a benchtop instrument, easy to service, easy to operate, and requires no lock masses, mass preselection, or chemical ionization conditions. The QE-GC demonstrated that it can be an alternative to the double focusing magnetic sector instruments (sector) for the high-resolution measurement of PCDD/Fs and PCBs in dairy products.

Mass Spectrometry for Analysis of Changes during Food Storage and Processing

“…A HR-GC system coupled with magnetic sector MS instrumentation has long been considered the gold standard for PCDD/Fs and PCBs analysis, in which the mass spectrometer was operated in EI mode and the MS data were recorded under selected ion monitoring (SIM) mode . A Q-Orbitrap mass spectrometer interfaced to a GC system was described by Hayward et al, enabling detection of 27 PCDD/Fs and PCBs in dairy foods, such as cow and human milk . An alternative approach was introduced by the European Union regulation in 2014, which used a triple quadrupole mass spectrometer working on multiple reaction monitoring (MRM) mode to increase selectivity and sensitivity for the detection of PCDD/Fs and PCBs .…”

“…37 A Q-Orbitrap mass spectrometer interfaced to a GC system was described by Hayward et al, enabling detection of 27 PCDD/Fs and PCBs in dairy foods, such as cow and human milk. 38 An alternative approach was introduced by the European Union regulation in 2014, which used a triple quadrupole mass spectrometer working on multiple reaction monitoring (MRM) mode to increase selectivity and sensitivity for the detection of PCDD/Fs and PCBs. 39 The method was validated in a variety of food commodities, such as vegetable oil, fish, milk powder, biscuit, and soy products, and demonstrated comparable analytical performances (e.g., sensitivity, linearity, and precision) to the GC−HRMS method.…”

Open, High-Resolution EI+ Spectral Library of Anthropogenic Compounds

“…Since commercial release in 2015, the high-resolution gas chromatography Orbitrap mass spectrometer (GC Orbitrap MS) has been evidenced as a valuable tool in metabolomics (1-6), environmental (7)(8)(9)(10), clinical (11), and forensic analysis (12). The enhanced mass accuracy and greater achievable linear dynamic range (13), when operating in full-scan mode, makes GC Orbitrap MS particularly suited to chemical characterization of complex samples with unknown composition.…”

Trace-Level Persistent Organic Pollutant Analysis with Gas-Chromatography Orbitrap Mass Spectrometry—Enhanced Performance by Complementary Acquisition and Processing of Time-Domain Data

“…1,17,18 However, a single measurement of a trace concentration sample may not be robust enough to perform accurate quantitation. 1 The fundamental trade-off between sensitivity and mass resolution may niche out Orbitrap technology to survey analysis: the high resolution that is very valuable for nontarget analysis comes at the "cost" of detection limits. However, this is a common trade-off, and for instance, in sector field high-resolution (HR) instruments, the enhancement of resolution is associated with a reduction of the slit width, which cuts down the signal.…”