Journal of Environmental Treatment Techniques
2019, Volume 7, Issue 3, Pages: 234-244
∞
퐶푓
time, and the extraction temperature remain constant. As
equation (5) indicates, the extraction process is dependent on
the distribution constant Kfs. This is a characteristic
parameter that describes the properties of a coating and its
selectivity toward the analyte versus other matrix
components. Because of its solvent-free nature and the small
size of the fibre coating, SPME can be interfaced
conveniently to analytical instruments of various types. Only
extracted analytes are introduced into the instrument, since
the extracting phase is non-volatile and insoluble in most
organic solvents. Thus, there is no need for complex
injectors designed to deal with large amounts of solvents,
and these components can be simplified for use with SPME.
Depending on the method of subsequent analysis, the
sensitivity of determinations using the SPME technique is
very high, facilitating trace analysis. Although in most cases
the analytes are only partly extracted from the sample, all
extracted material is transferred to the analytical instrument,
resulting in good performance. Carryover should be checked
for each analyte and the desorption conditions should be
chosen so that the analyte remaining on the fibre is less than
퐾푓푠
=
ꢂ3ꢃ
ꢂ4ꢃ
퐶푠∞
푘 . 푉
푓푠
푠
∞
퐶푓 = 퐶ꢄ .
푘 . 푉 + 푉
푠
푓푠
푓
Equations (1) and (2) can be combined and rearranged
into equation (3). Finally, the number of moles of analyte n
extracted by the coating can be calculated from equation:
퐾 . 푉 . 푉
푓
푓푠
푠
∞
푓
ꢆ = 퐶 . 푉 = 퐶 .
ꢂ5ꢃ
푓
표
퐾 . 푉 + 푉
푓푠
푓
푠
Equation (5) indicates that the amount of analyte
extracted onto the coating (n) is linearly proportional to the
analyte concentration in the sample (C ), which is the
0
analytical basis for quantification using SPME.Equation (5),
which assumes that the sample matrix can be represented as
a single homogeneous phase and that no headspace is present
in the system, can be modified to account for the existence
of other compartments in the matrix, by considering the
volumes of the individual phases and the appropriate
distribution constants. In addition, when the sample volume
0.1% of the initial amount. The solvent free process results
in narrow bands reaching the instrument, giving taller,
narrower peaks and better quantification. (See Fig. 1).
2
.3.4 Data analysis
Study of the essential oil extraction by Clevenger
is very large, i.e. V
s
>> Kfs·V
f
, equation (4) can be simplified
method from Cuscuta epithymum and Pyrethrum roseum
plant Clevenger method was used for the isolation of
essential oil as a traditional method of extracting essential
oils from medicinal plants. The effects of different
extracting solvents such as n-hexane (non-polar) and
methanol were studied on the extraction of the essential oil
from Cuscuta epithymum and Pyrethrum roseum. Each time,
the obtained essential oil was analyzed using Gas
chromatography (GC). According to the obtained results of
the previous studies and the beneficial effects of medicinal
herbs, the aims of this study were extraction and
investigation of the essential oil from Cuscuta epithymum
and Pyrethrum roseum and evaluation of its effects to Inhibit
blood cancer cells Growth. The results related to the
essential oil are presented in the chromatograms. One of the
active ingredients of essential oil is 2-methoxy-6-pentyl-1,4-
dihydroxybenzene which is identified as having
antimicrobial and anti-tumor properties.
to:
ꢆ = 퐾 . 푉 . 퐶
ꢄ
ꢂ6ꢃ
푓푠
푓
Which points to the usefulness of the technique when the
volume of the sample is unknown. In practice, the fibre can
be exposed directly to the flowing blood, ambient air, water,
etc. The amount of extracted analyte will correspond directly
to its concentration in the matrix, without depending on the
sample volume. The amount of analyte extracted onto the
fibre coating is at a maximum when the equilibrium is
reached, thus achieving highest sensitivity. If sensitivity is
not a major concern of analysis, shortening the extraction
time is desirable. In addition, the equilibrium extraction
approach is not practical for solid porous coatings, due to the
displacement effect at high concentrations. For these
circumstances, the extraction is stopped and the fibre is
analyzed before the equilibrium is reached. The kinetics of
absorption of analytes onto a liquid fibre coating can be
described as:
epithymum and Pyrethrum roseum
The chemical composition of the essential oil from
Cuscuta epithymum and Pyrethrum roseum
퐾 . 푉 . 푉
푓푠
푠
푓
ꢆ = ꢂ1 − 푒ꢇ푎ꢈ ꢃ. 퐶표.
ꢂ7ꢃ
퐾 . 푉 + 푉
푠
was
푓푠
푓
determined by gas chromatography connected to a mass
spectrometer (GC-MS). There were identified different
compounds of the essential oil from this plant. The most
important extracted compounds of the essential oil from
chemical analysis by GC-MS are shown in table 2 and the
where t is the extraction time, and a is a time constant,
representing how fast an equilibrium can be reached. When
the extraction time is long, equation (6) becomes equation
(
4), characterizing equilibrium extraction. If the extraction
equilibrium is not reached, equation (6) indicates that there
is still a linear relationship between the amount (n) of analyte
extracted onto the fibre and the analyte concentration (C ) in
0
the sample matrix, provided that the agitation, the extraction
.
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