Modified HS-SPME for determination of quantitative relations between low-molecular oxygen compounds in various matrices

• Modified HS-SPME system with Carbowax fiber for analysis of complex samples is presented.
• Sample is replaced by its suspension/emulsion in polyethylene glycol (PEG).
• Similar quantitative relations between sample components established by tested HS-SPME and direct analysis are achieved.
• Specific interactions between sample components and Carbowax fiber coating dominate in the examined system.
• The presented system significantly shortens optimization of HS-SPME procedure for polar constituents mixtures.

Similar quantitative relations between individual constituents of the liquid sample established by its direct injection can be obtained applying Polydimethylsiloxane (PDMS) fiber in the headspace solid phase microextraction (HS-SPME) system containing the examined sample suspended in methyl silica oil. This paper proves that the analogous system composed of sample suspension/emulsion in polyethylene glycol (PEG) and Carbowax fiber allows to get similar quantitative relations between components of the mixture as those established by its direct analysis, but only for polar constituents. It is demonstrated for essential oil (EO) components of savory, sage, mint and thyme, and of artificial liquid mixture of polar constituents. The observed differences in quantitative relations between polar constituents estimated by both applied procedures are insignificant (Fexp < Fcrit). The presented results indicates that wider applicability of the system composed of a sample suspended in the oil of the same physicochemical character as that of used SPME fiber coating strongly depends on the character of interactions between analytes-suspending liquid and analytes-fiber coating.

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