4th EucheMs chemistry congress

tuesday, 28-Aug 2012
s600
chem. Listy 106, s587–s1425 (2012)
Analytical chemistry Electrochemistry, Analysis, sample manipulation
separation methods – i
o - 1 2 9
AnALySiS of voLAtiLe frACtion of thyMuS
PAnnoniCuS And CorreLAtionS with
inorGAniC PLAnt CoMPoSition By StAtiC
heAdSPACe GAS ChroMAtoGrAPhy, MASS
SPeCtroMetry And AtoMiC SPeCtroMetry
S. rAziC 1 , J. ArSeniJeviC 2 , z. MAKSiMoviC 2 ,
J. MArKoviC 3 , i. SoStAriC 4
1 University of Belgrade Faculty of Pharmacy, Department of
Analytical Chemistry, Belgrade, Serbia
2 University of Belgrade Faculty of Pharmacy, Department of
Pharmacognosy, Belgrade, Serbia
3 University of Belgrade, Vinca Institute of Nuclear Sciences,
Belgrade, Serbia
4 University of Belgrade Faculty of Agriculture, Department of
Botany, Belgrade, Serbia
Depending on specific analytical technique producing
samples, the term “volatile fraction” could be related to analytical
headspace, essential oil, flavor, fragrance, aroma or extract. There
is a large and usually puzzling diversity of volatile organic
compounds (VOCs) emitted by plants and only partly explained
functions in biotic and abiotic media. On the other hand inorganic
components, especialy trace elements require a different
experimental approach in analysis. For elucidation of their role
and learning about possible relations with specific organic
components additional chemometrics approach will be applied.
Inorganic plant composition explains only a small part of variation
in essential oil composition but, is there any correlation with
volatile compounds sampled differently?
Fifteen plant individuals of Thymus pannonicus All.
(Lamiaceae) were collected during flowering period in southern
Banat (Serbia). Dry leaves were immediately after comminuting
hermetically sealed and subjected to static headspace extraction
(SHS), followed by GC and GC-MS analysis. After SHS-GC
analysis, the same samples were subjected to microwave-assisted
acid digestion. The resulting solutions were used for
determination of several elements (Na, K, Ca, Mg, Fe, Mn, Zn,
Cu, Cr, Mo, Co and Ni) by atomic absorption and emission
spectroscopy (FAAS, GF-AAS and ICP-AES).
Monoterpenes dominated in all examined headspace
extracts, ranging 57.85–96.11%. Extracts with monoterpene
hydrocarbons as principal compounds contained limonene,
myrcene, α-pinene, E-β-ocimene and camphene in amounts up to
42.99 %, 39.54 %, 35.58%, 23.56% and 15.81%, respectively. In
oxigenate monoterpenes-rich extracts geranial, neral, 1,8-cineole
and linalool were the most abundant (23.44%, 22.10%,
12.52% and 11.99%, respectively) and also contained non
terpenic compounds in substantial amounts (13.15–25.20%),
mainly 6-methyl-5-hepten-2-one (8.85 – 16.01%). Sesquiterpene
hydrocarbons and oxygenate sesquiterpenes constituted a small
fraction of analyzed headspace extracts, 1.53–5.20% in total.
The obtained results are subjected to the chemometrics
analysis (PCA and CA) in order to highlight possible
relationships.
Keywords: Analytical Methods;
separation methods – i
4 th EucheMs chemistry congress
o - 1 3 0
deveLoPMent of hydroPhiLiC interACtion
Liquid ChroMAtoGrAPhy (hiLiC) StAtionAry
PhASeS in MonoLithiC CAPiLLAry forMAtS
A. e. funA 1 , L. BArron 1 , n. w. SMith 1
1 King’s College London (University of London), Micro
Separations Group, London, United Kingdom
The interest in hydrophilic interaction liquid
chromatography (HILIC) stationary phases largely lies on their
potential for effective separation of small, highly polar molecules:
a problem distinctly besetting conventional reversed-phase
materials. Development in capillary formats could further support
important micro-separation applications in pharmaceutical
analysis, toxicology and proteomics, amongst others. The wide
availability of monomers opens possibilities to tailor polymeric
monoliths to exhibit HILIC behaviour. One of these is exploiting
the zwitterionic nature of polymerisable betaines, e.g. N-(3-
-Sulfopropyl)-N-(methacryloxyethyl)-N,N-dimethylammonium
betaine (SPE). The challenge lies in maximising as much
zwitterionic moieties available for surface interaction as well as
achieving the most favourable morphology. This study
investigated the separation of selected nitrogenous bases and
nucleosides in monoliths prepared by thermally-initiated
co-polymerisation of SPE and ethylene glycol dimethacrylate in
fused silica capillaries of different internal diameters
(50–200 µm). The influence of monomer concentration,
porogenic solvent polarity and polymerisation temperature on
selectivity was studied. Reduction in reaction time and increase
in capillary diameter have distinctly resulted in higher efficiencies.
HILIC behaviour was very predominant when acetonitrile
concentration in the mobile phase was higher than 70 %. The
effect of buffer salt concentration and pH in the mobile phase was
also demonstrated. Further optimisations are carried out,
ultimately towards developing applied methods for drug analysis
using LC-MS.
Keywords: liquid chromatography; polymers; microporous
materials;
AUGUst 26–30, 2012, PrAGUE, cZEcH rEPUbLIc