American Journal of Analytical Chemistry, 2013, 4, 668-673
Published Online November 2013 (http://www.scirp.org/journal/ajac)
http://dx.doi.org/10.4236/ajac.2013.411080
Open Access AJAC
A Validated High-Performance Thin-Layer
Chromatography (Hptlc) Method for the Quantitative
Determination of Tricin in Two Spergularia Species
Omnia Gamal El-Dien, Eman Shawky*, Amal H. Aly, Rokia M. Abdallah, Nabil A. Abdel-Salam
Pharmacognosy Department, Faculty of Pharmacy, University of Alexandria, Alexandria, Egypt
Email: *shawkyeman@yahoo.com
Received September 24, 2013; revised October 26, 2013; accepted November 8, 2013
Copyright © 2013 Omnia Gamal El-Dien et al. This is an open access article distributed under the Creative Commons Attribution
License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
ABSTRACT
A simple, sensitive, precise and robust high-performance thin-layer chromatographic (HPTLC) method for analysis of
tricin has been developed and validated for the determination of tricin in genus Spergularia. Analysis of tricin was per-
formed on pre-coated TLC aluminum plates with silica gel as the stationary phase. Linear ascending development was
carried out in double twin trough glass chamber saturated with a mobile phase consisting of chloroform: methanol (37:3
v/v). Spectro-densitometric scanning was performed by TLC scanner III (CAMAG) in absorbance mode at the wave-
length of 270 nm. The system was found to give compact spots for tricin (Rf value of 0.34 ± 0.04). The linear regres-
sion analysis data for the calibration plots showed a good linear relationship with r2 = 0.9981 in the concentration range
2 - 15 μl with respect to peak area. According to the International Conference on Harmonization (ICH) guidelines, the
method was validated for precision, recovery, and robustness. The tricin content quantified from Spergularia marina
and S. daiandra was found to be 0.398 mg/100g and 1.642 mg/100g fresh weight, respectively. Statistical analysis of
the data showed that the method is reproducible and selective for the estimation of tricin.
Keywords: Spergularia marina; S pergularia dia nd ra; HPTLC; Quantitative; Tricin
1. Introduction
Tricin possesses several biological properties that are
superior to other flavonoids and polyphenols in terms of
agricultural, nutraceutical and pharmaceutical values [1].
It has long been credited for its beneficial effects: as an
antioxidant due to its potent inhibition of lipoperoxida-
tion and its sparing effect on vitamin E in erythrocyte
membranes; as an antiviral; antihistaminic; immune-
modu-latory and anti-tubercular activities [2-4]. The pro-
mising anti-ulcerogenic activity of tricin and its 7-gluco-
side was recently reported with a curative ratio of 77 and
79%, respectively [5]. Tricin is a potent COX (Cy-
clooxygenase) inhibitor. The inhibition of COX enzyme
activity by tricin was apparently isoenzyme-nonselective,
which renders it more comparable with non-steroidal
anti-inflammatory drugs, such as sulindac and aspirin,
rather than to coxibs [6-8].
One of the most prominent and well documented fea-
tures of tricin is its potential antitumor/anticancer activity.
Based on a study of structure-activity relationships of
flavonoid-induced cytotoxicity on human leukemia cells,
tricin is considered one of the most potent anti-cancer
agents tested so far and this is most probably due to the
stability of its structure [9].
Recently a simple HPLC method for the quantitation
of tricin in human plasma has been reported and cross-
validated in mouse plasma, liver and small intestinal
mucosa. The work was designed to contribute to the de-
velopment of tricin as a potential chemo-preventive agent
in humans [10].
Being the dominant flavone pigment in whole wheat
meal, tricin has prompted the elaboration of a method for
tricin isolation and quantification, based on ultrasonic-
assisted extraction and ultra-performance HPLC purifi-
cation, and guided by electrospray ionization MS [11].
A recent HPLC method for tricin isolation and quanti-
fication in the pressed juice of Medicago sativa was es-
tablished [1]. In addition, a simple, precise, and rapid
method was developed for the determination of tricin and
4'-methoxy-tricin in the Tibetan herbal medicine of Py-
*Corresponding author.
O. G. EL-DIEN ET AL. 669
rethrum tatsienense by the high-performance liquid chro-
ma-tographic technique coupled with photodiode array
detection [12].
Among the modern Analytical tools, HPTLC is a pow-
erful analytical method equally suitable for qualitative and
quantitative analytical tasks. HPTLC is playing an im-
portant role in today’s analytical world, not in competition
to HPLC but as a complementary method [13].
HPTLC produces visible chromatograms complex in-
formation about the entire sample available at a glance.
Multiple samples are seen simultaneously, so that refer-
ence and test samples can be compared for identification.
Similarities and differences are immediately apparent and
with the help of the image comparison. Several chroma-
tograms can be compared directly, even from different
plates. They can be evaluated either by the image based
software video-scan or by scanning densitometry with
TLC scanner, measuring the absorption and/or fluores-
cence of the substances on the plate. TLC is an offline
technique: the subsequent steps are relatively independent,
allowing parallel treatment of multiple samples during
chromatography, derivatization and detection.
We managed to isolate tricin for the first time from
genus Spergularia. Tricin was isolated from the chloro-
form fraction of Spergularia marina; meanwhile it was
found in the chloroformic fraction of Spergularia dian-
dra in a large amount.
In view of the fore-mentioned points, the aim of this
work is to develop a simple, non expensive, accurate,
specific and repeatable HPTLC method for the determi-
nation of tricin in Genus Spergularia. Literature review
revealed that only one HPLTC method has been reported
for the analysis of tricin among other five flavonoids, but
the method was not thoroughly validated [14].
2. Experimental
2.1. Chemicals and Reagents
HPTLC analyses were performed on Merck 20 cm × 10
cm (0.25 mm) plates. Tricin used as standard material
was obtained from the Department of Pharmacognosy,
Faculty of Pharmacy, University of Alexandria and
tested for its purity by TLC and spectroscopic method.
All the reagents used in the experiment were of analytical
grade and were supplied by Merck, Darmstadt, Germany.
2.2. Preparation of Standard Solution
A weight of 4.0 mg of standard tricin was accurately
weighed, quantitatively transferred into a 10 ml volumet-
ric flask, dissolved in methanol and the volume was ad-
justed with the same solvent.
2.3. Preparation of Sample Solutions
Fresh aerial parts, 500 g of each of Spergularia marina
and Spergularia diandra were accurately weighed and
exhaustively extracted using (2 L) 70% ethanol at room
temperature. Each alcoholic extract was concentrated to
200 ml volume, fractionated successively by (600 ml)
petroleum ether, then by (600 ml) chlorofrorm. The
chloroform fraction was evaporated under reduced pres-
sure to give 440 mg of extract for S. marina and 770 mg
for S. diandra. A weight of 225 mg of each of the
chloroformic fraction of Spergularia marina and Sper-
gularia diandra were accurately weighed, dissolved in a
mixture of methanol and chloroform (8:2), transferred
quantitatively to 10 ml volumetric flask, adjusted to
volume with the same mixture and shaken to mix thor-
oughly to give samples A and B, respectively.
2.4. HPTLC—Densitometric Procedure
2.4.1. Instrumentation
Sample solutions for HPTLC analyses were applied by
means of a CAMAG (Wilmington, NC) Linomat IV
automated spray-on band applicator. Zones were quanti-
fied by linear scanning at 270 nm with a CAMAG TLC
Scanner 3 with a deuterium source in the reflection mode,
slit dimension settings of length 6 and width 0.1, mono-
chromator bandwidth 20 nm, and a scanning rate of 15
mm·s1. The peak areas of chromatograms were deter-
mined using CATSTLC software (version 4.X).
2.4.2. Chromatographic Procedure
Sample and standard solutions were applied in the form
of bands on pre-coated HPTLC silica gel plates 60 F-254
(20 cm × 10 cm with 250 µm thickness) by means of
Linomat IV automated spray-on band applicator operated
with the following settings: band length 6 mm, applica-
tion rate 15 s/µl, distance between each two bands 4 mm,
distance from the plate side edge 1 cm, distance from the
bottom of the plate 1 cm.
The volumes applied for routine analysis were dupli-
cate 1.0 μl, 3.0 μl and 5.0 μl of the TLC tricin standard
(0.4, 1.2 and 2.0 μg) and triplicate 6 μl and 4 μl aliquots
of samples solutions A and B respectively. A volume of
20 ml of mobile phase (system IV) were used for devel-
opment.
Linear ascending development of the plates was car-
ried out in 20 cm × 20 cm Camag HPTLC twin trough
chamber saturated with the mobile phase. The optimized
chamber saturation time for the mobile phase was 30 min
at room temperature. Plates were developed to a distance
of 8 cm beyond the origin. The development time was 17
min. After development, the plates were air-dried for 5
min. Densitometric scanning was performed on Camag
TLC scanner III in the reflectance-absorbance mode at λ
270 nm and operated by WINCATS software (V. 3.1).
The source of radiation utilized was deuterium lamp
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O. G. EL-DIEN ET AL.
670
emitting a continuous UV spectrum between 190 and 400
nm. The slit dimension was kept at 6 mm × 0.1 mm.
Concentrations of the samples and standards chroma-
tographed were determined from the intensity of dif-
fusely reflected light. Evaluation was done by peak area
measurement with linear regression.
2.5. Validation
The method was validated according to the ICH guide-
lines on the validation of analytical methods [15]. All
results were expressed as percentages, where n represents
the number of values. For the statistical analysis, Excel
2003 (Microsoft Office) was used. A 5% level of sig-
nificance was selected.
2.5.1. Calibration and Quantification
As recommended by the International Committee on
Harmonization (ICH) guidelines [15], a calibration curve
was established using six analyte concentrations (1.0, 2.0,
3.0, 4.0, 5.0 and 6.0 μl/zone) of the TLC standard applied
in triplicate, representing 0.4 - 2.4 μg of tricin. For rou-
tine analytical procedures, a three-point calibration curve
within this range was used, produced by applying dupli-
cate 1.0, 3.0 and 5.0 μl (0.4, 1.2, 2.0 μg) of the HPTLC
standard on each plate.
2.5.2. Specificity
The specificity of the method was determined by analyz-
ing standard drug and test samples. The spots for tricin
and samples were confirmed by comparing the Rf and
spectrum of the spot with that of a standard. The peak
purity of tricin was assessed by comparing the spectra at
three different levels, that is, peak start (S), peak middle
(M), and peak end (E) positions of the spot.
2.5.3. Accuracy
The accuracy of the method was validated by a standard
addition analysis. The sample solutions were spiked with
three different known concentrations of tricin. An aliquot
of 2 ml of sample B solution of known previously deter-
mined concentration (0.24 mg/ml) was mixed with 3 ml
of standard tricin solution (0.12 mg/ ml) to give mixture 1,
another 2 ml aliquot of the same sample solution was
mixed with 3 ml of standard tricin solution (0.24 mg/ml)
to give mixture 2, and a third 2 ml aliquot of the same
sample solution was mixed with 3 ml of standard tricin
solution (0.36 mg/ml) to give mixture 3. The original and
the three fortified sample solutions (mixtures 1, 2 and 3)
were analyzed on the same plate by application of tripli-
cate 4.0 μl, 6.0 μl, 4.0 μl and 4.0 μl volumes, respectively,
in addition to the three standards described earlier for
routine analyses which were applied in duplicate. The
difference between the expected concentrations and the
found ones was calculated to determine the accuracy of
the method.
2.5.4. Precision
In accordance with the ICH guidelines [15], precision was
determined by independent repeated analysis of six dif-
ferent tricin standard solutions by the use of the same
equipment and the same analytical procedure in the same
laboratory and on the same plate. The assay was repeated
in the same day for intra-day precision and on different
days to obtain inter-day precision.
2.5.5. Limit of Detection (LOD) and Limit of
Quantification (LOQ)
According to the ICH guidelines, the detection limit (DL)
may be expressed as DL = 3.3 σ/S, while, the quantita-
tion limit (QL) may be expressed as QL = 10 σ/S, where
σ = the standard deviation of the response S = the slope
of the calibration curve. The slope S is estimated from
the calibration curve. The estimate of σ was carried out
by studying the calibration curves, where the standard
deviations of y-intercepts of regression lines were used
as the standard deviation.
3. Results and Discussion
Mixtures of several mobile phases were tried to separate
spot of tricin from other spots and get stable peak. The
solvent system used was System chloroform: methanol
(37:3 v/v) was selected for analysis of tricin, which gave
good resolution. Good chromatogram in Figures 1-3 was
attained with Rf value 0.38 ± 0.04. The wavelength of 270
nm was used for quantification of sample as it gave the
best sensitivity.
The selectivity of the separation and the specificity of
the detection were shown by the densitograms and com-
parison of the superimposed UV spectra, respectively
(Figure 4). The peak purity of tricin was assessed by
Figure 1. Overlay of in-situ absorption spectra obtained
from the band of standard tricin and the corresponding
band obtained from chloroform extracts of S. marina and S.
diandra scanning from 200 to 400 nm.
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O. G. EL-DIEN ET AL. 671
Figure 2. HPTLC scan-densitogram showing the separation
of tricin (7) from other components in the sample A at 270
nm.
Figure 3. HPTLC scan-densitogram showing the separation
of tricin (3) from other components in the sample B at 270
nm.
Figure 4. A 3-dimential of a series of sample A, B and stan-
dard tricin applied on the same plate with increasing con-
centrations showing an increase in the area of successive
peaks in samples and standard.
comparing its respective spectra at the peak start, apex,
and peak end.
Visual observation of the calibration curves was done
which reveals that the calibration curve is linear. The
intercept of the calibration lines is slightly different from
zero. From these we can say that, this kind of methods
shows saturation on the spots and because of that it pro-
duces curved calibrations. However, here linearity can fit
the calibration responses at narrow range but intercept
deviate from zero. The results showed linear relationship
between the peak areas and the tricin concentrations. The
plot was linear in the range of 0.4 - 2.4 μg/spot (y = 7463
x + 583.6, r2 = 0.998). The three-point calibration was
repeated many times and was also found to have a linear
regression correlation coefficient of 0.999.
LOD and LOQ were found to be 0.0513 and 0.155
µg/spot respectively. Results are shown in Table 1.
The results of repeatability and intermediate precision
study of tricin are depicted in Table 2. The developed
method was found to be precise as the %RSD values for
repeatability and intermediate precision studies were less
than 2%.
Results of recovery studies by addition of tricin stan-
dard in triplicate are depicted in Table 3.
The method was found to be robust by studying the
effect of alteration of mobile phase composition. The
results of change in mobile phase composition in terms of
standard deviation of the peak areas calculated as the %
RSD was found to be less than 2% (Table 4).
The method was employed for the determination of
tricin content in the total extract of Spergularia marina
and S. diandra, where % w/w tricin in fresh total weight
was found to be 0.398 mg/100g fresh weight and 1.642
mg/100g fresh weight for Spergularia marina and S.
diandra, respectively.
4. Conclusion
TLC and TLC-densitometry have been largely investi-
gated for purity testing, pharmaceutical dosage form as-
say and herbal fingerprinting [16]. These methods are
flexible and cost-effective and present the advantage of
the simultaneous processing of standards and samples
with versatile detection possibilities, including a great
variety of post-chromatographic derivatization reagents
due to the short analysis time and low solvent consump-
tion. The results of the analysis of marketed formulation
using the proposed HPTLC method are highly repro-
ducible and reliable. HPTLC method is found to be simple,
sensitive, accurate, precise, specific, robust and economi-
Table 1. Linear regression data for the calibration curve of
tricin.
Tricin
Linearity range (µg/spot) 0.32 - 2.88
Intercept (a) 583.6
Slope (b) 7463
Correlation coefficient (r) 0.999172
LOD (µg/spot) 0.051238
LOQ (µg/spot) 0.155266
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672
Table 2. Precision of the HPTLC method for the determination of tricin (repeatability).
Intra-day precision Inter-day precision
Experiment number
Concentration (μg/spot) Mean ± SDRSD % Concentration (μg/spot) Mean ± SDRSD %
1
0.399
0.406
0.398
0.401
±
0.004
1.108
0.401
0.402
0.409
0.404
±
0.004
1.046
2
0.808
0.823
0.797
0.809
±
0.013
1.624
0.809
0.805
0.807
0.807
±
0.002
0.253
3
1.218
1.216
1.221
1.218
±
0.003
0.207
1.218
1.211
1.195
1.208
±
0.012
0.969
4
1.583
1.622
1.640
1.615
±
0.029
1.815
1.615
1.615
1.630
1.620
±
0.009
0.546
5
1.984
2.002
2.038
2.008
±
0.028
1.369
2.008
2.027
2.009
2.015
±
0.010
0.504
6
2.273
2.269
2.348
2.297
±
0.045
1.941
2.422
2.362
2.348
2.377
±
0.040
1.662
Table 3. Results of the standard addition experiments.
Mix. Concentration of tricin
in sample (mg/ml )
Concentration of
tricin added (mg/ml )
Concentration of tricin found
in mixture (mg/ml)* Recovery (%) ± SD RSD %
1 0.24 0.12 0.166 98.95 ± 1.56 1.59
2 0.24 0.24 0.242 100.66 ± 1.614 1.6
3 0.24 0.36 0.317 101.48 ± 1.44 1.41
*Each concentration is the average of three determinations.
Table 4. Robustness testing.
Parameter S.D. R.S.D. %
Mobile phase composition 0.072 1.3
Amount of mobile phase 0.03 0.82
Time from spotting to chromatography 0.05 0.97
Time from chromatography to scanning 0.06 0.74
cal and it can be used for the routine analysis of tricin in
genus Spergularia L.
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