GC–MS Analysis of A Helichrysum italicum Hydrosol: Sensitivity, Repeatability and Reliability of Solvent Extraction versus Direct Hydrosol Analysis

Abstract

Hydrosols have been increasingly used in the food industries as drinks and as ingredients for seasoning and flavoring. Research has shown they have antimicrobial, antioxidative and anti-inflammatory effects and therefore have potential as food preservative agents and sanitizing agents for tools used in the food industry. The composition analysis of hydrosols is commonly conducted using extraction with organic solvents. However, some hydrophilic compounds are lost with this procedure, leading to issues in identifying native composition and potential adulteration. In this paper, different methods for hydrosol analysis are studied. The methods differ in sample preparation, number of detected compounds, repeatability and reliability. Direct hydrosol analysis and 1:1 extraction with organic solvent were determined to be the most appropriate in our experiments. However, the method implementation depends on the application. Direct hydrosol analysis is simple and does not change ratios among compounds; its drawback is poor repeatability. Using 1:1 extraction has good repeatability; however, some hydrophilic compounds are lost, and adulterations with cosolvents and the addition of solubilizers cannot be discovered.

Multiple liquid‐liquid extraction of dissolved compounds in immortelle hydrosol with four different solvents

“…Other major compounds in this report were 2,2dimethylnon-5-en-3-one (8.8-13.0 %), 3-octanone (8.0-12.3 %) and α-terpineol (7.6-9.1 %), while in the observed Croatian populations 2,2-dimethylnon-5-en-3-one (14.69-18.40 %) and αterpineol (11.8-19.55 %) were listed as the major compounds. On the other hand, our results do not agree with those of Kokalj Ladan and Kočevar Glavač [12] who reported 1,8-cineole (34.7 %), terpinen-4-ol (14.4 %), α-terpineol (14.0 %), and linalool (10.4 %) as major components of immortelle hydrosol. Furthermore, some reports dealing with the chemical composition of immortelle hydrosol, indicated that α-terpineol is reported as the most dominant compound (15.6-30.5 %) [9][10][11] whereas this compound was not detected in our hydrosol sample.…”

“…Moreover, the ratios between the compounds detected in the hydrosol may differ from their original chemical composition due to different partition coefficients between water and organic solvent for each compound present in the hydrosol. [12]…”

“…[8] Although the chemical analyses of immortelle essential oil have been extensively and thoroughly reported, very few reports paid attention to the chemical composition of hydrosols. [9][10][11][12] The reason for this is probably that the preparation of samples for the chemical analysis of hydrosols is somewhat more difficult than the analysis of essential oils. [12] For quality analysis of hydrosols, nonpolar compounds that are dissolved to a low percentage are usually obtained by repeated liquid-liquid extraction (LLE) with nonpolar solvents of different polarity indices.…”

“…[9][10][11][12] The reason for this is probably that the preparation of samples for the chemical analysis of hydrosols is somewhat more difficult than the analysis of essential oils. [12] For quality analysis of hydrosols, nonpolar compounds that are dissolved to a low percentage are usually obtained by repeated liquid-liquid extraction (LLE) with nonpolar solvents of different polarity indices. [13] The solvent is then evaporated by a non-thermal process in a nitrogen stream to concentrate the constituents and make them suitable for GC and GC-MS analysis.…”

“…Among many other useful aromatic plant species, essential oil of immortelle ( Helichrysum italicum ) has found wide use in the cosmetic and perfume industry in the last decade due to its confirmed anti‐aging properties [8] . Although the chemical analyses of immortelle essential oil have been extensively and thoroughly reported, very few reports paid attention to the chemical composition of hydrosols [9–12] . The reason for this is probably that the preparation of samples for the chemical analysis of hydrosols is somewhat more difficult than the analysis of essential oils [12] .…”