Maša Islamčević Razboršek,a,* Darinka Brodnjak Vončina,a Valter Doleček,a Ernest Vončinab
a
Faculty of Chemistry and Chemical Engineering, University of Maribor, Smetanova
17, SI-2000 Maribor, Slovenia.
Tel.: +386(2)2294431,
Fax: +386(2)2527774,
E-mail: masa.islamcevic@uni-mb.si.
b Institute of Public Health Maribor, Institute of Environmental
Protection, Prvomajska 1, SI-2000 Maribor, Slovenia
Paper based on a
presentation at the 12th International Symposium on Separation
Sciences, Lipica, Slovenia,
September 27–29, 2006.
Abstract
A gas chromatographic-mass
spectrometric (GC-MS) method for the simultaneous identification and
quantification of seven major phenolic and terpenic compounds in Rosmarinus
officinalis L. was developed. The compounds were identified as
trimethylsilyl (TMS) derivatives of phenolic acids (caffeic and rosmarinic acid),
phenolic diterpene (carnosic acid), and pentacyclic triterpenes (ursolic,
oleanolic, betulinic acid and betulin). These compounds have been identified by
retention time and comparison of mass spectra. The procedure involves ultrasonic
extraction using solvent mixture of tetrahydrofuran and ethanol. Extracts were
fractionated by size exclusion chromatography (SEC) after purifying on
graphitised carbon. The fraction with phenolic and terpenic compounds was
derivatised prior to GC-MS analysis using N-methyl-N-trimethylsilyl
trifluoroacetamide (MSTFA) as a derivatisation reagent. The derivatisation
process was optimized regarding temperature and reaction time. The linearity of
the method was tested in concentration range 4–25 mg L–1. The
correlation coefficients (r2) were in the range of 0.997 to
0.999. The average recoveries for all compounds ranged from 80 to 82%. The GC-MS
technique is specific and sensitive, and can be used for simultaneous
identification and determination of a wide range of phenolic and terpenic
compounds in different plants even at trace levels.
Keywords: diterpenes, triterpenes, Rosmarinus officinalis L., size exclusion chromatography, gas chromatography, mass spectrometry.