Research Article
Received: 2 June 2009;
Revised: 5 March 2010;
Accepted: 25 March 2010
Published online in Wiley Online Library: 24 June 2010
(wileyonlinelibrary.com) DOI 10.1002/pca.1231
Characterisation of Two South American Food
and Medicinal Plants by Chemometric
Methods based on their Multielemental
Composition
Miguel A. Cantarelli,a,b Roberto G. Pellerano,b Luis A. Del Vitto,c
Eduardo J. Marchevskyb,d and José M. Camiñaa,d*
Introduction – The chemometric characterisation of two plants frequently used as food and medicinal species, Achyrocline
satureioides and Achyrocline venosa (Asteraceae: Gnaphalieae), was carried out based on their mineral composition. Both
species, known by the common name of ‘marcelas’, are very similar in their morphological features but they have different
medicinal and food properties.
Objective – To develop multivariate models for the classification of A. satureiodes and A. venosa based on their mineral content.
Methodology – The analytic determinations were made by means of inductively coupled plasma optical emission spectrometry
from aerial parts of the plants. An internal standard was used to evaluate the accuracy in the sample treatment and the
recovery of toxic elements was studied. The multivariate methods used include principal components analysis, cluster analysis
and linear discriminant analysis.
Results – Classification for both A. satureioides and A. venosa was successful in all cases using only four variables: aluminium,
iron, magnesium and sulphur content. The concentrations of the following elements were determined: Al, As, Ba, Ca, Cd, Co, Cr,
Cu, Fe, K, La, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sr, Ti, V, Y and Zn.
Conclusions – This method is useful to identify both species in raw material in order to detect eventual errors of selection.
Copyright © 2010 John Wiley & Sons, Ltd.
Keywords: Achyrocline satureioides; Achyrocline venosa; chemometric methods; toxic and trace elements
Introduction
550
Over recent years there has been a significant increase in the use
of herbal medicine. Medical doctors are also prescribing herbal
teas and herbal extracts as a supplementary type of treatment for
everyday problems caused by modern civilisation. The use of
medicinal plants in both crude and prepared forms has greatly
increased (Eisenberg et al., 1998; Yeh et al., 2002), and although
herbal remedies are often perceived as being natural and therefore safe, they are not free from adverse effects (Ernst, 2002 a,b).
Considering the complexity of these drugs and their inherent
biological variation, it is necessary to evaluate their safety, efficacy and quality (WHO, 1991).
Achyrocline satureioides (Lam.) DC. (Asteraceae : Gnaphalieae),
known under the common name of ‘Marcela’, is a South American
plant used as traditional medicine and also in the beverage
industry. It is used in infusions because of its digestive and antispasmodic properties, and its extract is the base of some bitter
drinks that are widely consumed in the region known as
‘amargos’. Many studies have been carried out regarding the
chemical composition and properties of A. satureioides (Ruffa
et al., 2002; Kadarian et al., 2002; Gugliucci and Menini, 2002; De
Souza et al., 2002, 2004; Arredondo et al., 2004; Cosentino et al.,
2008), including its relation to weight loss (Dickel et al., 2007).
Because of the extensive use of this plant, the acute toxicity of its
extract in rats was determined (Rivera et al., 2004). The properties
of its essential oils such as trypanocydal (Rojas de Arias et al.,
1995) and mosquito repellent (Gillij et al., 2008) have been
proved. In view of such evidence, A. satureioides is an important
food and medicinal resource in Argentina, and hence a priority
plant for conservation studies (Martinez et al., 2006). In contrast,
A. venosa is not known regarding its nutritional and medicinal
properties, although it can be mistaken for A. satureioides due to
the similar morphological features, and wrongly used in the
food and beverage industry. Frequently, these two species are
* Correspondence to: J. M. Camiña, Facultad de Ciencias Exactas y Naturales,
Universidad Nacional de La Pampa, Av. Uruguay 151 (6300) Santa Rosa, La
Pampa, Argentina. E-mail: jcaminia@yahoo.com
a
Facultad de Ciencias Exactas y Naturales, Universidad Nacional de La
Pampa, Av. Uruguay 151 (6300) Santa Rosa, La Pampa, Argentina
b
Instituto de Química de San Luis (INQUISAL), Facultad de Química Bioquímica y Farmacia, Universidad Nacional de San Luis, Chacabuco y Pedernera (5700) San Luis. Argentina
c
Departamento de Farmacia y Herbario, Projects 8702 and 22/Q616, Universidad Nacional de San Luis, Av. Ejército de los Andes 950 (5700) San Luis,
Argentina
d
CONICET, Consejo Nacional de Investigaciones Científicas y Técnicas, Argentina. Av. Rivadavia 1917 (C1033AAJ) Ciudad de Buenos Aires, Argentina
Copyright © 2010 John Wiley & Sons, Ltd.
Phytochem. Anal. 2010, 21, 550–555
Characterization of Two South American Plants
harvested together for medicinal and industrial purposes,
because only an experienced botanist can distinguish them. For
this reason, it is important to find a method to identify both
plants in order to avoid errors or adulterations that can affect
human health. Furthermore, there are no reports concerning the
major, minor, trace and toxic elements in A. satureioides and A.
venosa, although such knowledge is significant considering the
wide use of these plants in South America.
The presence of heavy metals in plants may cause serious
health problems including renal failure, chronic toxicity and liver
damage (Shaw et al., 1997; Andrew et al., 2003). According to the
World Health Organisation (WHO, 1991), the concentration of
lead, cadmium, chromium and other heavy metals must be controlled in medicinal plants in order to ensure their safety. Thus,
the analysis of toxic and trace elements in food and medicinal
plants has been targeted by several research groups worldwide
(Abou-Arab and Abou Donia, 2000; Lemberkovics et al., 2002;
Marchisio et al., 2005; Maiga et al., 2005; Nookabkaew et al., 2006;
Gómez et al., 2007; Kara, 2009).
For the purposes of classification, the most commonly used
multivariate calibration methods (Massart et al., 1997; Mongay
Fernandez, 2005) are:
(1) Principal components analysis (PCA)—the original data are
reduced to few new variables, known as principal components (PCs). This approach permits the detection of several
characteristics that cannot be seen in the original data, which
can help to identify the differences within the original data
and to obtain groups or families.
(2) Cluster analysis (CA) – based on the ability to establish relationships between data using different criteria of similitude.
The use of amalgamation and distance criteria permit the
construction of a tree or dendogram that shows the possible
groups and their differences.
(3) Linear discriminant analysis (LDA)—used to confirm the classification made through PCA or CA, which are unsupervised
methods, in which the origin of grouping cannot be confirmed and that grouping can proceed from an unknown
source. LDA is a supervised method that uses a model (discriminant equations) that can classify mathematically different groups within unknown samples (Mongay Fernandez,
2005).
This paper discusses the multielemental composition of A. satureioides and A. venosa, including Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe,
K, La, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sr, Ti, V, Y and Zn, which were
analysed by inductively coupled plasma optical emission spectrometry (ICP-OES), and the classification of both plants by means
of the multivariate methods PCA, CA and LDA.
Experimental
Samples
Phytochem. Anal. 2010, 21, 550–555
Ultrapure nitric acid was acquired from Sigma (St. Louis, MO, USA). All
standard solutions were prepared using spectroscopic grade Merck
(Darmstadt, Germany) reagents. Ultrapure water (18.2 MW cm) was
obtained using a Barnstead Easy-Pure RF compact water system
(Dubuque, IA, USA).
Sample preparation and extraction
The aerial parts of the plants were dried in a oven at 75°C during approximately 24 h until constant weight. Afterwards the material was ground
using a Wiley 3379 series grinder and passed through a sieve (0.50 mm
diameter). The powder (2.0 g) was transferred to a porcelain crucible and
5 mL of indium solution (500 mg/L) was added as internal standard to
evaluate the degree of recovery. The mixture was covered with a cap and
reduced to ashes in a furnace at 500°C for 6 h. The ashes were dissolved
with 5.0 mL of concentrated nitric acid until the evolution of gases had
stopped. Then the solution was transferred to a 50 mL volumetric flask
and completed to the mark with deonised water (Abou-Arab and Abou
Donia, 2000; Maiga et al., 2005).
Analytical procedure
The concentrations of the 24 elements and internal standard were determined by direct nebulisation using a Varian ICP-OES model ICP-OES Vista
Pro, with a Czerny-Turner monocromator, holographic diffraction grid and
a VistaChip charge coupled device (CCD) array detector. The wavelengths
(nm) used for measurement of each element are indicated in Table 1.
Calibration curves for each element were constructed in triplicate using
five different concentrations. The regression coefficient (r2) values of such
curves ranged from 0.995 to 0.999.
Software
PCA was carried out using the Unscrambler 6.11 software package
(Trondheim, Norway). Cluster analysis was carried out using the InfoStat
software package (Córdoba, Argentina). For CA, the amalgamation criterion was complete linkage and the selected distance was the Euclidean
one. For LDA, the InfoStat software was also employed.
Recovery assay
In order to demonstrate the validity of the analytical procedure, a recovery study was carried out. A synthetic solution containing four toxic elements (Cr, Pb, Cd and As) was prepared and added to the dried samples
Table 1. Wavelengths used for ICP-OES analysis
Element
Al
As
Ba
Ca
Cd
Co
Cr
Cu
Fe
In
K
La
Mg
a
Wavelengtha
Element
Wavelengtha
308.215
193.696
455.403
317.933
226.502
228.616
267.716
324.754
259.940
303.963
766.491
398.850
279.079
Mn
Mo
Na
Ni
P
Pb
S
Sr
Ti
V
Y
Zn
257.610
202.032
588.995
231.604
213.618
220.353
181.972
181.972
337.280
292.402
371.031
213.856
Expressed in nm.
Copyright © 2010 John Wiley & Sons, Ltd.
551
Nineteen samples of each plant population (A. satureioides and A. venosa)
were harvested from the mountains near the city of San Luis, Argentina, at
850 m above sea level, in the summers of 2007 and 2008. The species
were authenticated by comparison with herbarium samples deposited at
the Universidad Nacional de San Luis (UNSL) and identified as follows:
Achyrocline satureioides (Lam.) DC (voucher specimen: L.A. Del Vitto no.
8603) and Achyrocline venosa Rusby (voucher specimen: L.A. Del Vitto & al.
no. 6765).
Reagents
View this article online at wileyonlinelibrary.com
M. A. Cantarelli et al.
(2.0 g) of Achyrocline venosa (Table 2). The extraction and analyses of the
concentrations of the four elements were determined according to the
protocol described earlier and the recovery percentage was determined.
Results and Discussion
Validation and recovery
The method of standard addition is considered as a validation
method (ICH, 1994; Prichard et al., 1996; Gómez et al., 2007). The
addition of indium as internal standard serves for evaluating the
recovery percentage as well as the losses in the ashing step (Kara,
2009). In the present work, the addition of indium was performed
prior to the mineralisation step and the mean recovery value was
98.2 ⫾ 3.1% (n = 38), similar to the results reported by Abou-Arab
and Abou Donia (2000). The recovery percentages obtained in
the four-metal-recovery assay were considered satisfactory
ranging from 98.7 to 102.0 % (Table 2).
Multielement composition analysis
Both plants contained high concentrations of K, Ca, Mg, P and
S. The concentrations of K, Ca and Mg were similar to those
reported previously for Hungarian herbs (Lemberkovics et al.,
2002; 16276, 6281 and 1472 mg/kg, respectively), demonstrating
that these elements are the most abundant in medicinal plants.
In contrast, the concentrations of P and S in A. satureioides and A.
venosa were smaller compared with those of Hungarian herbs
(Lemberkovics et al., 2002; mean values: 2730 and 2085 mg/kg,
respectively).
The toxic elements Pb, Cr, Cd and As were also present in A.
satureioides and A. venosa respectively, although the concentrations were below the permissible limits in foods, which are 10,
120, 0.3 and 4 mg/kg, respectively (WHO, 1991). The concentrations of Pb, Cr and Cd were lower in comparison with those of
medicinal plants from Egypt (Abou-Arab and Abou Donia, 2000;
mean values: 3.87, 16.01 and 1.45 mg/kg, respectively), but
similar to those of Hungarian tea (Lemberkovics et al., 2002;
<1.26 mg/kg for Pb and Cd; 3.47 mg/kg for Cr).
All the other elements were present at low concentrations.
Table 4 shows the acceptable limits for Zn, Ni, Cu and Fe (Maiga
Monitoring of toxic metals in crop and medicinal plants is particularly important in developing countries where such plants are
essential for the diet and health of the population (Maiga et al.,
2005). Table 3 shows the concentrations of the 24 elements
analysed in A. satureioides and A. venosa.
Table 4. Permissible limits for medicinal herbs for Zn, Ni, Cu
and Fe; and concentration ranges of Al, Ba, and Sr found in A.
satuterioides and A. venosa
Element
Cr
Pb
Cd
As
Addeda
Founda,b
Recoveredc
4.52 ⫾ 0.82
2.06 ⫾ 0.13
0.21 ⫾ 0.02
0.58 ⫾ 0.21
2.0
1.5
0.3
1.0
6.56
3.54
0.51
1.57
102.0
98.7
100.0
99.0
60a
10a
40a
45b
Zn
Ni
Cu
Fe
Table 2. Validation method for the recovery of toxic elements
Initial valuea
Limit
Range
ASa
52–1136
56–105
39–77
Al
Ba
Sr
AVa
223–403
26–57
26–37
a
Concentration in mg/kg.
Mean value (n = 7).
c
[(found-initial)/added] ¥ 100.
a
b
b
Expressed in mg/kg.
Expressed in mg per day.
Table 3. Concentrations of major, minor, trace and toxic elements in Achyrocline venosa and Achyrocline satureioides
Plants
Element concentration (mg/kg dry weight )a
Ba
Ca
Al
As
A. venosa
A. satureioides
324 ⫾ 42
606 ⫾ 169
0.58 ⫾ 0.14
0.96 ⫾ 0.32
45 ⫾ 8
66 ⫾ 10
A. venosa
A. satureioides
Cr
4.52 ⫾ 0.55
3.33 ⫾ 1.38
Cu
17 ⫾ 2
12 ⫾ 1
A. venosa
A. satureioides
Mn
108 ⫾ 6
152 ⫾ 16
A. venosa
A. satureioides
S
1032 ⫾ 121
732 ⫾ 40
a
Cd
Co
6044 ⫾ 364
7448 ⫾ 51
0.21 ⫾ 0.02
0.16 ⫾ 0.02
0.70 ⫾ 0.16
0.36 ⫾ 0.08
Fe
482 ⫾ 14
639 ⫾ 22
K
10838 ⫾ 607
11737 ⫾ 812
La
0.25 ⫾ 0.08
1.75 ⫾ 0.47
Mg
1699 ⫾ 238
1438 ⫾ 280
Mo
0.99 ⫾ 0.13
1.07 ⫾ 0.15
Na
148 ⫾ 16
166 ⫾ 23
Ni
3.12 ⫾ 0.23
2.12 ⫾ 0.65
P
1672 ⫾ 161
1228 ⫾ 177
Pb
2.06 ⫾ 0.09
1.96 ⫾ 0.28
Sr
31 ⫾ 3
44 ⫾ 8
Ti
22 ⫾ 2
25 ⫾ 2
V
1.07 ⫾ 0.16
1.43 ⫾ 0.40
Y
0.17 ⫾ 0.05
0.41 ⫾ 0.11
Zn
39 ⫾ 2
28 ⫾ 5
552
Average ⫾ standard deviation (n = 19).
View this article online at wileyonlinelibrary.com
Copyright © 2010 John Wiley & Sons, Ltd.
Phytochem. Anal. 2010, 21, 550–555
Characterization of Two South American Plants
et al., 2005) and the concentration ranges for the nonessential
elements Al, Ba and Sr detected in A. satureioides and A. venosa.
Such concentrations were similar to those reported previously for
other species (Nookabkaew et al., 2006; mean values: 1124, 59.65
and 60.29 mg/kg, respectively). In A. venosa, the concentration of
Co was two-fold higher than that of herbal teas from Thailand
(Nookabkaew et al., 2006; mean value: 0.260 mg/kg) and Turkey
(Kara, 2009; mean value: 0.23 mg/kg), whereas in A. satureioides
the concentration of Co was comparable to those detected in the
same teas. The concentration of V was similar to that found in
herbs from Thailand (Nookabkaew et al., 2006; mean value:
0.84 mg/kg) and Argentina (Gómez et al., 2007; mean value:
1.29 mg/kg). The concentration of La in A. satureioides was fivefold higher than in medicinal tea leaves from Turkey (Kara, 2009;
mean value: 0.37 mg/kg), whereas in A. venosa the concentration
80
of La was similar to that found in the same tea. The concentrations of Ti and Mo were higher than those reported for other
herbal medicines (Lemberkovics et al., 2002; mean values: 2.02
and <0.05 mg/kg, respectively).
Principal component analysis
The PCA model was obtained using three PCs, which can explain
99% of the original information on the variables. Through this
model, it was possible to obtain a good classification. Figure 1
shows a 3D score plot, in which A. venosa is shown on the right
(samples 1–19) and A. satureioides is shown on the left (samples
20–38). The final model was obtained using as variables the elements Al, Fe, Mg and S present in the 38 samples (19 for each
species), since their influence is higher than that of the other
elements. Figure 2 shows a 3D loading plot, which explains the
influence of original variables on the model. S had an important
10 4
15
12
60
7
2535
2326
20 29
33 21
36 31
22
34 32
-20
0,4
8
16
3 17
2 186
9
13 1
5
11
19
30
-40
Al
PC 3
0
Mg
0,6
14
-400 -300 -200 -100
0
100
200
300
PC 1
400
0,2
Fe
0,0
-0,2
80
40
0
-40
-80
-0,4
PC 2
PC 3
20
-60
0,8
24 28
38
3727
40
-0,6
-0,4
S
-0,2
0,0
PC
Figure 1. Three-dimensional score plot for 38 samples of Achyrocline
genus: samples 1–19 belong to A. venosa (left group); samples 20–38
belong A. satureioides (right group).
0,8
0,6
0,4
0,2
1
0,2
0,4
PC
0,0
0,6
0,8
-0,2
2
Figure 2. Three-dimensional loadings plot to evaluate the influence of
variables on the PC for Achyrocline genus classification.
1
6
5
2
3
8
4
18
9
13
10
14
7
11
16
17
12
15
19
20
21
26
23
24
27
38
28
29
22
33
30
32
34
25
31
35
36
37
0
100
200
300
400
500
600
700
Distance
Dendogram plot of 38 samples of Acyrocline genus. Samples 1–19 A. venosa; samples 20–38 A. satureioides.
Phytochem. Anal. 2010, 21, 550–555
Copyright © 2010 John Wiley & Sons, Ltd.
View this article online at wileyonlinelibrary.com
553
Figure 3.
M. A. Cantarelli et al.
Table 5. Results of classification obtained by linear discriminant analysis
A. venosa
A. satureioides
Total
Error (%)
16
0
16
0
16
16
16
16
32
0
0
0
3
0
3
0
3
3
3
3
6
0
0
0
Training
AV
AS
Total
Prediction
AV
AS
Total
influence on PC1, while the influence of Mg, Al and Fe was not so
great. Al, Mg and S greatly influenced PC2, whereas Fe had little
influence. Regarding PC3, Mg was the most important variable,
followed by Al and Fe; S seemed to present little influence.
Cluster analysis
The dendogram (Fig. 3) shows the classification obtained for
A. venosa (samples 1–19) and A. satureioides (samples 20–38)
using the variables Al, Fe, Mg and S. Both plants were successfully
classified.
Linear discriminant analysis
Once again, Al, Fe, Mg and S were used as variables to confirm the
results obtained with PCA and CA. The classification of Achyrocline
plants according to LDA is shown in Table 5. Sixteen samples of
each species were used for the training step, while for the prediction step only three samples of each species were used. All
samples were predicted in the correct form without error for both
cases in the training and prediction steps. The canonical discriminant function obtained using the variables mentioned was D =
-20.06 + 0.01 Al + 0.02 Fe—0.02 Mg—0.01 S (Mongay Fernandez,
2005).
The present work represents a valuable contribution for the
improvement of knowledge regarding the elemental composition of A. satureioides and A. venosa. In addition, it was demonstrated that the two species, as well as their by-products, can be
classified by three different methods according to their use as food
and medicine. Hence the methods reported can be applied in the
quality control of these plants and their derivatives, to detect
possible adulterations or to avoid mistakes in the selection of raw
materials for the beverage and phytopharmaceutical industries.
Acknowledgements
The authors are grateful to Professor Roberto Olsina (Universidad
Nacional de San Luis) for providing The Unscrambler 6.11 software. We would also like to thank Facultad de Agronomía, Universidad Nacional de La Pampa for providing the InfoStat
software. We are grateful for research grants from Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de La Pampa and Universidad Nacional de San Luis that
supported this research.
References
554
Abou-Arab AAK, Abou Donia MA. 2000. Heavy metals in Egyptian spices
and medicinal plants and the effect of processing on their levels.
J Agric Food Chem 48: 2300–2304.
View this article online at wileyonlinelibrary.com
Andrew AS, Warren AJ, Barchowsky A, Temple KA, Klei L, Soucy NV, O’Hara
KA, Hamilton JW. 2003. Genomic and proteomic profiling of responses
to toxic metals in human lung cells. Environ Health Persp 111: 825–838.
Arredondo MF, Blasina F, Echeverry C, Morquio A, Ferreira M,
Abin-Carriquiry JA, Lafon L, Dajas F. 2004. Cytoprotection by Achyrocline satureioides (Lam) D.C. and some of its main flavonoids against
oxidative stress. J Ethnopharmacol 91: 13–20.
Cosentino M, Bombelli R, Carcano E, Luini A, Marino F, Crema F, Dajas F,
Lecchini S. 2008. Immunomodulatory properties of Achyrocline satureioides (Lam.) D.C. infusion: A study on human leukocytes. J Ethnopharmacol 116: 501–507.
De Souza KCB,Schapoval EES, Bassani VL. 2002. LC determination of flavonoids: separation of quercetin, luteolin and 3-O-methylquercetin in
Achyrocline satureioides preparations. J Pharmaceut Biomed 28: 771–
777.
De Souza KCB, Andrades ME, Da Silva EG, Bonatto F, Heydrich J,
Dal-Pizzola F, Schapoval EES, Bassani VL, Moreira JCF, Polydoroa M.
2004. Antioxidant, pro-oxidant and cytotoxic effects of Achyrocline
satureioides extracts. Life Sci 74: 2815–2826.
Dickel ML, Kuze Rates SM, Rejane Ritter M. 2007. Plants popularly used for
loosing weight purposes in Porto Alegre, South Brazil. J Ethnopharmacol 109: 60–71.
Eisenberg DM, Davis RB, Ettner SL, Appel S, Wilkey S, Rompay MV, Kessler
RC. 1998. Trends in alternative medicine use in the United States,
1990–1997: results of a follow-up national survey. J Am Med Assoc 280:
1569–1575.
Ernst E. 2002a. Toxic heavy metals and undeclared drugs in Asian herbal
medicines. Trends Pharmacol Sci 23: 136–139.
Ernst E. 2002b. Heavy metals in traditional Indian remedies. Eur J Clin
Pharmacol 57: 891–896.
Gillij YG, Gleiser RM, Zygadlo JA. 2008. Mosquito repellent activity of
essential oils of aromatic plants growing in Argentina. Bioresource
Technol 99: 2507–2515.
Gómez MR, Cerutti S, Sombra LL, Silva MF, Martinez LD. 2007. Determination of heavy metals for the quality control in argentinian herbal
medicines by ETAAS and ICP-OES. Food Chem Toxicol 45: 1060–1064.
Gugliucci A, Menini T. 2002. Three different pathways for human LDL
oxidation are inhibited in vitro by water extracts of the medicinal herb
Achyrocline satureoides. Life Sci 71: 693–705.
ICH. Harmonised Tripartite Guideline. Text on Validation of Analytical Procedures. International Conference on Harmonization: Geneva, 1994.
Kadarian C, Broussalis AM, Miño J, Lopez P, Gorzalczany S, Ferraro G,
Acevedo C. 2002. Hepatoprotective activity of achyrocline satureioides (LAM) D.C. Pharmacol Res 45: 57–61.
Kara D. 2009. Evaluation of trace metal concentrations in some herbs and
herbal teas by principal component analysis. Food Chem 114: 347–
354.
Lemberkovics E, Czinner E, Szentmihályi K, Balázs A, Szoke E. 2002. Comparative evaluation of Helichrysi flos herbal extracts as dietary sources
of plant polyphenols, and macro- and microelements. Food Chem 78:
119–127.
Maiga A, Diallo D, Bye R, Paulsen BS. 2005. Determination of some toxic
and essential metal ions in medicinal and edible plants from Mali.
J Agric Food Chem 53: 2316–2321.
Marchisio PF, Sales AM, Cerutti S, Marchevsky EJ, Martínez LD. 2005.
On-line preconcentration/determination of lead in Ilex paraguariensis
samples (mate tea) using polyurethane foam as filter with USN-ICPOES. J Hazard Mater 124: 113–118.
Martinez GJ, Planchuelo AM, Fuentes E, Ojeda M. 2006. A numeric index to
establish conservation priorities for medicinal plants in the Paravachasca Valley, Córdoba, Argentina. Biodivers Conserv 15: 2457–2475.
Massart DL, Vandeginste BGM, Buydens LMC, De Jong S, Lewi PJ, SmeyersVerbeke J. 1997. Handbook of Chemometrics and Qualimetrics, Vol. A.
Elsevier: Amsterdam; 366–368.
Mongay Fernandez, C. 2005. Quimiometría. Publicaciones Universidad de
Valencia: Valencia; 247–280.
Nookabkaew S, Rangkadilok N, Satayavivad J. 2006. Determination of
trace elements in herbal tea products and their infusions consumed in
Thailand. J Agric Food Chem 54: 6939–6944.
Prichard E, Mackay GM, Points J. 1996. Trace Analysis: A Structures
Approach to Obtaining Reliable Results. The Royal Society of Chemistry:
London; 38.
Rivera F, Gervaz E, Sere C, Dajas F. 2004. Toxicological studies of the
aqueous extract from Achyrocline satureioides (LAM) D.C. (Marcela).
J Ethnopharmacol 95: 359–362.
Copyright © 2010 John Wiley & Sons, Ltd.
Phytochem. Anal. 2010, 21, 550–555
Characterization of Two South American Plants
Rojas de Arias A, Ferro E, Inchausti A, Ascurra M, Acosta N, Rodriguez E,
Fournet A. 1995. Mutagenicity, insecticidal and trypanocidal activity
of some Paraguayan Asteraceae. J. Ethnopharmacol 45: 35–41.
Ruffa MJ, Ferraro G, Wagner ML, Calcagno ML, Campos RH, Cavallaro L.
2002. Cytotoxic effect of Argentine medicinal plant extracts on
human hepatocellular carcinoma cell line. J. Ethnopharmacol 79: 335–
339.
Shaw D, Leon C, Kolev S, Murray V. 1997. Traditional remedies and food
supplements. A 5-year toxicological study (1991–1995). Drug Safety
17: 342–356.
WHO. 1991. Guidelines for the Assessment of Herbal Medicines. World
Health Organisation: Munich; 28.6.
Yeh GY, Eisenberg DM, Davis RB, Phillips RS. 2002. Use of complementary
and alternative medicine among persons with diabetes mellitus:
results of a national survey. Am J Pulic Health 92: 1648–1652.
555
Phytochem. Anal. 2010, 21, 550–555
Copyright © 2010 John Wiley & Sons, Ltd.
View this article online at wileyonlinelibrary.com