Brazilian Journal of Analytical Chemistry - BRJAC - Brazilian Journal ...

determination o f volatile o r g a n iC C o m p o u n d s present in f r u i t f r o m t h e ge o n o m a g a m i o v a
a n d ge o n o m a p a u c i f l o r a p a l m trees u s i n g t h e spme t e C h n i q u e
the experiments, the fibers were not used more than
10 times each. All experiments were performed 3 times
and it was possible to observe good reproducibility of
the system
Because it is a complex multicomponent system, it
is not possible to say that the analysis conditions used
correspond to equilibrium partition. The main object of
the study was to analyze the largest possible amount
of compounds extracted from fruits. Experiments of
linearity, and equilibrium were not performed.
fi g u rE 1. to t a l i o n C h r o m a t o g r a m P r o f i l E o f t h E samPlEs ExtraCtEd By t h E
sPmE t E C h n i q u E f r o m t h E gE o n o m a g a m i o v a P a l m t rE E, u s i n g a Pdms
fiBEr a n d a n ExPosurE t i mE o f 30 m i n.
Figure 01 shows the total ion chromatogram profile
of the samples extracted from the Geonoma gamiova
palm tree using the SPME technique with the PDMS
fiber and exposure time of 30 min. The spectrum was
acquired using GC-IT-MS, operating in full-scan mode
with a mass range from m/z 40 to m/z 500. Identification
of the compounds was performed by comparing the
spectrum of the samples with a mass spectra library
(NIST).
The twenty tentatively identified compounds extracted
from the fruit of Geonoma gamiova can be observed in
Figure 01. In Table I, some of the compounds tentatively
identified by mass spectrum comparison after extraction
from the fruit of the Geonoma gamiova palm tree
are presented. In this table the retention time of the
identified compounds, as well as their mass spectra,
can also be observed.
The same experiment was carried out on fruit from
the Geonoma pauciflora palm tree. The characteristic
chromatographic profile is shown in Figure 02;
the compounds were also tentatively identified by
comparing their mass spectra with a NIST mass spectra
library. More than 30 different compounds were
extracted; however, some of these peaks could not be
identified due to low similarity with the spectra stored
in the NIST library.
fi g u r E 2. to t a l i o n C h r o m a t o g r a m P r o f i l E o f t h E samPlEs ExtraCtEd By t h E
sPmE t E C h n i q u E f r o m t h E gE o n o m a P a u C i f l o ra P a l m t rE E, u s i n g a Pdms
fiBEr a n d a n ExPosurE t i mE o f 30 m i n.
Table II shows the tentatively identified compounds
present in the fruit from Geonoma pauciflora, their
mass spectra and also their retention time. The two
tables show the similarity index for the identification of
compounds.
Analyzing the results we can see that the fruit
from the Geonoma gamiova palm tree contained 20
different volatile compounds, which could be extracted
and tentatively identified by the techniques employed,
while the Geonoma pauciflora palm contained 15
different volatile compounds that were extracted and
identified. Together, the palms contained five volatile
compounds in common: 1,2-benzenedicarboxylic acid,
n-capric acid n-heptyl ester, 3,5-bis(1,1-dimethylethyl)phenol,
2-hexyl-1-octanol.
co n c l u s Io n
The SPME technique was very efficient in extracting
volatile compounds from the fruit of the Geonoma
gamiova and Geonoma pauciflora palm trees.
SPME is a unique technique for sample preparation
because it addresses most of the drawbacks pertaining
to the extraction of organic compounds prevalent in
other methods, such as the use of solvents or complex
apparatus. The volatile compounds present in the fruit
were easily concentrated by the SPME fiber system,
which made even the analysis of low concentrations of
compounds possible.
In addition, the possibility of subsequent analysis
by gas chromatography / mass spectrometry, by only
carrying out the thermal desorption of compounds in
the injector of the chromatograph, made analyzing the
complex mixture of compounds present in the fruit of
palm trees much easier.
The use of the SPME technique reduced the
preparation and pre-concentration time for samples,
since all compounds are extracted simultaneously. The
166 Br J Anal Chem