Synthetic antioxidants have a harmful effect if
consumed by humans. Synthetic antioxidants such
as BHT (Butyl Hydroxy Toluene), TBHQ (Tertiary
Butyl Hydroquinone) can increase the occurrence of
carcinogenesis in humans (Amarowicz et al., 2000)
and liver damage (Osawa & Namiki, 1981).
Therefore, natural antioxidants are more
recommended for human consumption. This fact
encourages a lot of research done to look for natural
ingredients that can be used as antioxidants
(Rohman & Riyanto, 2005).
The working principle of GC-MS is based on
differences in the polarity and molecular mass of
samples that can be evaporated. Samples in the
form of liquid or gas are directly injected into the
injector, if the sample is solid, it must be dissolved
in a solvent that can be evaporated. The flow of gas
flowing will bring the evaporated sample to enter
the column. The components in the sample will be
separated based on the partition between the mobile
phase (carrier gas) and stationary phase (column).
The result is a gas molecule which will then be
ionized in a mass spectrophotometer so that the gas
molecule will experience fragmentation in the form
of positive ions. Ions will have a specific ratio
between the mass and the charge (Fowlis, 1998).
The principles of the Gas Chromatography -
Mass Spectrometry tool are: Sample injection can
be done manually or use an automatic sample taker
through a rubber seal that can be closed again. The
sample is evaporated on the portal part of the
injection which is heated and subjected to
condensation at the top of the column. The column
can be a packed capillary column or column, which
will be discussed in more depth. The mobile phase
used to carry samples through the column is a gas -
usually nitrogen or helium. The column is closed in
an oven which can be set at a temperature between
room temperature and approximately 400 ° C. The
detector used is mass spectrometry (MS). The
University of North Sumatra sample is inserted into
the instrument source by heating it at the end of a
sensor until it evaporates, aided by very hollow in
the instrument If it is in the vapor phase, the analyte
is bombarded with electron electrons produced by
the rhenium or tungsten filaments, which are
accelerated towards a positive target with an energy
of 70 eV. Two types of systems are usually used to
separate ions based on load comparisons of their
mass (Watson, 2005).
2 MATERIALS AND METHODS
2.1 Materials
The main material for this research is Eucalyptus
robusta. The solvent used in the distillation process
is aquadest. The reagents used in the DPPH test are
2,2-diphenyl-1-pikril hidrazil (DPPH) and
methanol. The instrumentation used for sampling
samples included the 1800 shimadzu UV-Vis
spectrometer.
2.2 Preparation of Sample
Leaves are obtained from PT. Toba Pulp Lestari
which is located on Jl. Indorayon Subdistrict Dolok
Nauli, Toba Regency Samosir, North Sumatra. The
selected leaves are leaves along with stems 5-10 cm
from the top of the plant. Taking is done in the
morning at 7-9 in the morning.
The fresh leaves obtained are immediately
separated from the stem. Then the leaves are
chopped using a cutter and scissors to produce
chopped ingredients with a length of ± 0.5-1.0 cm.
Plant identification has been carried out in the
HERBARIUM MEDANENSE (MEDA) Laboratory
in the Department of Biology, University of North
Sumatra. Samples in the form of: Fresh leaves in a
single branch between 10-15 cm from the top.
2.3 Sample Extraction
Eucalyptus leaves dried for 24 hours at room
temperature. Then the sample is weighed as much
as 150 grams and inserted into a 1000 mL size
flask. Adding aquabides to taste is then connected
to a Stahl distiller, and boiled for ± 5-6 hours at ±
100 ° C to produce oil and distillation ends when
the distillate is clear. The essential oil obtained is
accommodated in the Erlenmeyer glass. The
distillate obtained is a mixture of oil and water.
Then the oil layer was added to CaCl
2
anhydrous to
bind water which might still be mixed with essential
oils, the oil layer was decanted and put into vial
bottles, stored in a coolant in a bottle and tightly
closed. Then extracted samples are stored in glass
bottles for further analysis.
2.4 Characterization
2.4.1 Analysis of GC-MS
The Specifications Instrument GC-MS QP 2010S
Shimadzu, using Column 5MS with type of ion
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