Open Probe fast GC–MS — combining ambient sampling ultra‐fast separation and in‐vacuum ionization for real‐time analysis

Abstract

An Open Probe inlet was combined with a low thermal mass ultra-fast gas chromatograph (GC), in-vacuum electron ionization ion source and a mass spectrometer (MS) of GC-MS for obtaining real-time analysis with separation. The Open Probe enables ambient sampling via sample vaporization in an oven that is open to room air, and the ultra-fast GC provides ~30-s separation, while if no separation is required, it can act as a transfer line with 2 to 3-s sample transfer time. Sample analysis is as simple as touching the sample, pushing the sample holder into the Open Probe oven and obtaining the results in 30 s. The Open Probe fast GC was mounted on a standard Agilent 7890 GC that was coupled with an Agilent 5977A MS. Open Probe fast GC-MS provides real-time analysis combined with GC separation and library identification, and it uses the low-cost MS of GC-MS. The operation of Open Probe fast GC-MS is demonstrated in the 30-s separation and 50-s full analysis cycle time of tetrahydrocannabinol and cannabinol in Cannabis flower, sub 1-min analysis of trace trinitrotoluene transferred from a finger onto a glass surface, vitamin E in canola oil, sterols in olive oil, polybrominated flame retardants in plastics, alprazolam in Xanax drug pill and free fatty acids and cholesterol in human blood. The extrapolated limit of detection for pyrene is <1 fg, but the concentration is too high and the software noise calculation is untrustworthy. The broad range of compounds amenable for analysis is demonstrated in the analysis of reserpine. The possible use with alternate standard GC-MS and Open Probe fast GC-MS is demonstrated in the analysis of heroin in its street drug powder. The use of Open Probe with the fast GC acting as a transfer line is demonstrated in <10-s analysis without separation of ibuprofen and estradiol. Copyright © 2017 John Wiley & Sons, Ltd.

Electron Ionization Mass Spectrometry for Both Liquid and Gas Chromatography in One System without the Need for Hardware Adjustments

“…In LC–MS about 100 times more sample compounds could be analyzed due to about 100 times lower split ratio at the flow restriction capillary; (B) cold EI provides enhanced molecular ion that improves the identification, sensitivity, and selectivity in SIM mode; (C) cold EI eliminates ion source tailing and degradation; (D) cold EI provides much more uniform response than standard EI; (E) cold EI enables the analysis of much bigger compounds than standard EI; (F) we measured over 6 orders of magnitude measurement linear dynamic range (LDR) with EI–LC–MS with cold EI, which is much better than the LDR of any other LC–MS system. Flow injection analysis is an important additional benefit of the combined GC–MS and EI–LC–MS system with both standard EI and cold EI. It enables the competition with other forms of real time analysis such as DART , for samples that are already in liquids or via a simple solvation, but it does not provide real time analysis with separation as Open Probe Fast GC–MS. , …”

“…Flow injection analysis is an important additional benefit of the combined GC–MS and EI–LC–MS system with both standard EI and cold EI. It enables the competition with other forms of real time analysis such as DART , for samples that are already in liquids or via a simple solvation, but it does not provide real time analysis with separation as Open Probe Fast GC–MS. , …”

Recent Analytical Approaches in Quality Control of Cannabis sativa L. and Its Preparations

“…(Calvi et al, 2018b); Headspace solid-phase microextraction/gas chromatography-mass spectrometry HS-SPME/GC-MS technique followed by multivariate statistical tools were used for determination of the complete volatile organic compound (VOC) emission profiles of 48 seized samples. (Calvi et al, 2018a) By the year 2017-By using open Probe fast GC-MS -combining ambient sampling ultra-fast separation and invacuum ionization for real-time analysis of cannabis samples (Keshet et al, 2017). By the year 2016-Using GC-FID for quantification of 28 terpenes and verified via GC-MS (Aizpurua-Olaizola et al, 2016b).…”

Condensed Phase Membrane Introduction Mass Spectrometry with In Situ Liquid Reagent Chemical Ionization in a Liquid Electron Ionization Source (CP-MIMS-LEI/CI)

“…Other work in the literature with direct liquid ionization has been demonstrated by the Amirav group, who coupled LC to EI via supersonic molecular beams. , As an alternative DMS strategy, Amirav et al. also developed the “Open Probe” analytical strategy, which allows for direct sampling by ambient sample vaporization and fast GC separation (∼30 s) in advance of EI. , …”

“…30,31 As an alternative DMS strategy, Amirav et al also developed the "Open Probe" analytical strategy, which allows for direct sampling by ambient sample vaporization and fast GC separation (∼30 s) in advance of EI. 32,33 We have previously presented CP-MIMS with LEI as a direct analysis strategy for polycyclic aromatic hydrocarbons (PAHs) from both aqueous and soil samples. For soil samples, this method obviated sample cleanup, resulting in remarkably high throughput (15 soil samples per hour) combined with sensitive detection (70 μg/kg detection limit for benzo[a]pyrene from soil).…”