In the Master's thesis we studied qualitative and quantitative composition of hydrosols using gas chromatography coupled with mass spectroscopy (GC-MS). We also made a review of hydrolates that are avaliable on Slovenian market. They are mainly available in online shops, while minor supply is through local producers and larger stores. Most frequent were hydrosols of Lavandula angustifolia, Helychrisum italicum, Rosmarinus officinalis and Rosa damascena.
We analyzed the compostion of 12 Helychrisum italicum hydrosols of various manufacturers. After evaluating the sensitivity, repeatability and extraction yield, we chose double extraction with hexane(1:1 V/V ratio) and split ratio 1:10.
In direct hydrolate analysis, we identified 11–38 different compounds, in 1. extracts 19–58 compunds, while in 2. extracts there were 4–22 compounds. Compounds that were in higher contents (>1% of total volatiles) in 1. extracts were alcoholic monoterpenoids (α-terpineol, linalool, nerol, eucalyptol and borneol), ketones (4-6-dimethyloctan-3,5-dione, pentan-3-one, izopropil-etilketon, 4,6,9-trimethyl-8-decene-3,5-dione (»italadion«)) and n-undecane, an alkane. On average, terpineol-α represented the highest percentage of overall composition (20,10%) followed by 4,6-dimethyloctan-3,5-dione (11,24%), linalool (7,52%) and pentan-3one (6,87%). On average, pentan-3-one represented the highest percentage of compounds in 2. extracts. Some of compunds found in direct hydrolate analysis were detected only in direct samples and not in extracts. Those were various acids (phosphonic acid, etanoic acid, carbamic acid, benzoic acid) and salts (benzoic acid salt, carbamic acid salt). We chose 6 compounds (α-terpineol, linalool, pentan-3-one, eucalyptol, nerol and borneol) and quantified them using the external standard method and evaluated repeatability of measurements. Average concetrations of all 6 compounds were 30–395 mg/L. We also calculated total concentration of volatiles by using concentrations of 6 chosen compounds and their percentage of total volatiles. Total concentration of volatiles, in chosen hydrolates, ranged from 800 mg/L to 100 mg/L.
We concluded that hydrosols of Helychrisum italicum differ in the number, relative proportion and concentration of volatile compounds. However compounds that represent most of the composition are similar.
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