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Quantifiable Testing of Essential Oils
Quantifiable Testing of Essential Oils for Quality and Purity
Several quantifiable tests exist
that allow scientists, producers, suppliers and end users to be
able to test their oils to determine quality and help to ascertain
if an oil is pure and of the quality sought after for each particular
Gas Chromatography and Mass Spectroscopy (GC-MS)
Testing by means of Gas Chromatography
and Mass Spectroscopy can help to verify that the constituents contained
within an essential oil sample are representative of what that particular
essential oil should contain.
Gas Chromatography and Mass Spectroscopy
are two separate tests that are usually both conducted on an oil
specimen to identify constituents contained within it. Mass Spectrometry
assists in identification of the specific constituents measured
within Gas Chromatography, so typically, both tests are done together.
Gas Chromatography, also known as
Gas Liquid Chromatography is abbreviated as GC or
Gas Chromatography measures the constituents
contained within a particular essential oil sample by plotting each
constituent found within the sample onto a graph. To begin, a sample
of the oil is placed into the heating chamber of the gas chromatograph
machine. The oil sample is then heated to a specific temperature
until the constituents vaporize. Each constituent vaporizes at a
different rate of time. As each constituent vaporizes, is passes
through a detector that measures a) the time it took for the constituent
to vaporize and b) the percentage/concentration of the constituent
within the particular sample.
The gas chromatograph machine plots
a graph of the results. The x-axis identifies the time that passes
between the vaporization of each constituent. The y-axis shows the
percentage concentrations of each constituent within the oil.
Mass Spectrometry, abbreviated as
MS is often used in conjunction with Gas Chromatography as
it can aid in determining if a sample contains any adulterants.
Each compound, after passing through
the gas chromatograph machine, is fed into the mass spectrometer.
The Mass Spectrometer ionizes the compounds, sorts each by their
mass-to-charge ratio and then measures their molecular weights.
The results are then charted.
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