Hyphenation of ultra high performance supercritical fluid chromatography with atmospheric pressure chemical ionisation high resolution mass spectrometry: Part 1. Study of the coupling parameters for the analysis of natural non-polar compounds

• Published in: Journal of Chromatography A 2017-08, Vol.1509, p.132-140
• Main Authors: Duval, Johanna, Colas, Cyril, Pecher, Virginie, Poujol, Marion, Tranchant, Jean-François, Lesellier, Eric
• Format: Article
• Language: English
• Subjects: Analytical chemistry; Chemical Sciences; High-resolution mass spectrometry; Hyphenation; Make-up location; Make-up solvent; Ultra high performance supercritical fluid chromatography; Vegetable oil
• ISSN: 0021-9673; 1873-3778
• DOI: 10.1016/j.chroma.2017.06.016

•Development of an adapted UHPSFC-HRMS instrument.•UHPSFC-APCI-HRMS used for a vegetable oil analysis.•Effects of the make-up location on APCI mass response.•Nature of the make-up solvent on the compound ionization efficiency in UHPSFC-HRMS. An analytical method based on Ultra-High-Performance Supercritical Fluid Chromatography (UHPSFC) coupled with Atmospheric Pressure Chemical Ionization − High-resolution mass spectrometry (APCI-Q-TOF-HRMS) was developed for compounds screening from oily samples. The hyphenation was made using a commercial UHPLC device coupled to a CO2 pump in order to perform the chromatographic analysis. An adaptation of the injection system for compressible fluids was accomplished for this coupling: this modification of the injection sequence was achieved to prevent unusual variations of the injected volume related to the use of a compressible fluid. UHPSFC-HRMS hyphenation was optimized to enhance the response of the varied compounds from a seed extract (anthraquinones, free fatty acids, diacylglycerols, hydroxylated triacylglycerols and triacylglycerols). No split was used prior to the APCI ionization source, allowing introducing all the compounds in the spectrometer, ensuring a better sensitivity for minor compounds. The effects of a mechanical make-up (T-piece) added before this ionization source was discussed in terms of standard deviation of response, response intensity and fragmentation percentage. The location of the T-piece with regards to the backpressure regulator (BPR), the flow rate and the nature of the make-up solvent were studied. Results show that the effects of the studied parameters depend on the nature of the compounds, whereas the make-up addition favours the robustness of the mass response (quantitative aspect).