The concentration of As, Cr and Pb toxic elements was determined in three species of amaranth seeds: A. hypochondriacus, A. cruentus and A. dubius. The determinations were carried out by inductively coupled plasma optic atomic spectroscopy (ICP-OES). The result shows that Cr and As were found in minor concentrations than allowed by the World Health Organization (WHO; 120 and 4 mg kg-1 respectively); As (mg kg-1): A. dubius (0.76) A. cruentus (<0.50) and A. hypochondriacus (< 0.50); Cr (mg kg-1):  A. dubius (9.79) A. cruentus (1.55) and A. hypochondriacus (1.52). However, the concentration of Pb was high (A. dubius (19.04) A. cruentus (30.20) and A. hypochondriacus (35.56) more than the maximum of WHO (10 mg kg-1). To avoid systematic error, recovery and validation studies were performed: recovery test: 102.3%; validation (by standard addition): 96.0 ? 103.1%. Due to the fact that amaranth had been proposed as new food due to its nutraceutical properties, the high concentration of Pb found in this study indicates that Pb should be evaluated in these amaranth species to avoid the intake of toxic element by human beings.Fil: Aguilar, Elba Graciela. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; ArgentinaFil: Cantarelli, Miguel Angel. Consejo Nacional de Investigaciones Cienti­ficas y Tecnicas. Instituto de Ciencias de la Tierra y Ambientales de la Pampa; Argentina. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Marchevsky, Eduardo Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; ArgentinaFil: Escudero, Nora L.. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; ArgentinaFil: Camiña, José Manuel. Consejo Nacional de Investigaciones Cienti­ficas y Tecnicas. Instituto de Ciencias de la Tierra y Ambientales de la Pampa; Argentina. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales; Argentin

Aguilar, Elba Graciela

Camiña, José Manuel

Cantarelli, Miguel Angel

Escudero, Nora L.

Marchevsky, Eduardo Jorge

Journal of Chemistry

The concentration of As, Cr, and Pb toxic elements was determined in three species of amaranth seeds: A. hypochondriacus, A. cruentus, and A. dubius. The determinations were carried out by inductively coupled plasma optical atomic spectroscopy (ICP-OES). The result shows that Cr and As were found in minor concentrations than allowed by the World Health Organization (WHO; 120 and 4 mg kg−1 resp.); As (mg kg−1): A. dubius (0.76) A. cruentus (<0.50) and A. hypochondriacus (<0.50); Cr (mg kg−1): A. dubius (8.19) A. cruentus (1.15) and A. hypochondriacus (1.20). However, the concentration of Pb was high: A. dubius (19.04) A. cruentus (30.20) and A. hypochondriacus (35.56) more than the maximum of WHO (10 mg kg−1). To avoid systematic error, recovery and validation studies were performed: recovery test: 102.3%; validation (by standard addition): 96.0–103.1%. Due to the fact that amaranth had been proposed as new food due to its nutraceutical properties, the high concentration of Pb found in this study indicates that Pb should be evaluated in these amaranth species to avoid the intake of toxic element by human beings

Elba Graciela Aguilar

Miguel Angel Cantarelli

Eduardo Jorge Marchevsky

Nora Lilian Escudero

José Manuel Camiña

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Study and Determination of As, Cr, and Pb in Amaranth Seeds

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Hindawi Publishing CorporationJournal of ChemistryVolume 2013, Article ID 138391, 4 pageshttp://dx.doi.org/10.1155/2013/138391Research ArticleStudy and Determination of As, Cr, and Pb in Amaranth SeedsElba Graciela Aguilar,1 Miguel Angel Cantarelli,2,3 Eduardo Jorge Marchevsky,4Nora Lilian Escudero,1 and José Manuel Camiña2,31 Facultad de Quı́mica, Bioquı́mica y Farmacia, Universidad Nacional de San Luis, Chacabuco y Pedernera, 5700 San Luis, Argentina2 Facultad de Ciencias Exactas y Naturales, Universidad Nacional de La Pampa, Avenida Uruguay 151,Santa Rosa, 6300 La Pampa, Argentina3 Instituto de Ciencias de la Tierra y Ambientales de La Pampa (INCITAP), Avenida Uruguay 151 Santa Rosa,6300 La Pampa, Argentina4 Instituto de Quı́mica San Luis (INQUISAL), Chacabuco y Pedernera, 5700 San Luis, ArgentinaCorrespondence should be addressed to Miguel Angel Cantarelli; miguelcantarelli@yahoo.com.arReceived 8 May 2013; Revised 4 July 2013; Accepted 7 July 2013Academic Editor: Theocharis C. StamatatosCopyright © 2013 Elba Graciela Aguilar et al. This is an open access article distributed under the Creative Commons AttributionLicense, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properlycited.The concentration of As, Cr, and Pb toxic elements was determined in three species of amaranth seeds: A. hypochondriacus, A.cruentus, andA. dubius.Thedeterminationswere carried out by inductively coupled plasma optical atomic spectroscopy (ICP-OES).The result shows thatCr andAswere found inminor concentrations than allowed by theWorldHealthOrganization (WHO; 120 and4mg kg−1 resp.); As (mg kg−1): A. dubius (0.76) A. cruentus (<0.50) and A. hypochondriacus (<0.50); Cr (mg kg−1): A. dubius (8.19)A. cruentus (1.15) and A. hypochondriacus (1.20). However, the concentration of Pb was high: A. dubius (19.04) A. cruentus (30.20)and A. hypochondriacus (35.56) more than the maximum ofWHO (10mg kg−1). To avoid systematic error, recovery and validationstudies were performed: recovery test: 102.3%; validation (by standard addition): 96.0–103.1%. Due to the fact that amaranth hadbeen proposed as new food due to its nutraceutical properties, the high concentration of Pb found in this study indicates that Pbshould be evaluated in these amaranth species to avoid the intake of toxic element by human beings.1. IntroductionAmaranth is a plant species that was frequently used inAmerica before the Spanish conquest. Then, this crop wasno longer consumed and amaranth was forgotten. From atotal of 70 species belonging to the Amaranthus genus, 40 arefrom America. At present, amaranth is studied as food dueto its high protein content, its excellent amino acid profile,and nutraceutical properties. It is known that amaranth canconcentrate heavymetals and there are numerous reports thatshow this ability: a previous work reported the accumulationof Cd inAmaranthus in both shoot and root ofA. hybridus,A.spinosus, A. viridis, and A. rudis [1]. Other authors reportedthe effect and accumulation of heavy metals by amaranthin saline soils [2]. Also, the ability of Amaranthus dubiusand Amaranthus hybridus to bioconcentrate several mineralelements was proved [3]. Iron, lead, and zinc concentrationswere studied in amaranth plants from Kenya [4].The contentof several metals, such as Al, Fe, Ni, Cr, and Pb, was deter-mined in amaranth [5]. Both the effect of As in the growthof amaranth plants and a new method for the extraction ofAs from the plants were reported [6]. In Nigeria, both, thebioconcentration of trace elements in leaves of Amaranthuscaudatus [7] as well as the study of trace elements inAmaranthus hybridus [8] were carried out. On the otherhand, trace elements were analyzed in leaves of Amaranthushybridus from Africa [9]. The uptake of As and heavy metalsby native Amaranthus blitoides was studied in Spain [10];as a result, the use of Amaranthus albus and Amaranthusblitoides was proposed for bioremediation in contaminatedzones [11].Amaranthus hybriduswas studied due to its poten-tial danger of bioaccumulation of toxic trace metals underbiosolid amended irrigated soils if plants are used as ediblevegetables [12]. A recent report [13] reveals that the intakeof Amaranthus lividus, hybridus, and dubius harvested fromcontaminated soils may be dangerous to human health due2 Journal of Chemistryto their ability to accumulate metals. The Cd accumulationability of A. hybridus, showing high bioconcentration factorsin soil culture and hydroponic solution [14]was also reported.Amaranth seeds have very important nutritional proper-ties and they are very frequently used to obtain flours. Thepreviously mentioned reports studied the concentration ofseveral transition elements in leaves and roots of differentspecies ofAmaranthus although toxic elements have not beenpreviously studied in their seeds.Due to the toxic effect of this plant for intake and also toits negative effect for human health, this paper discusses theconcentration of the toxic elements: As, Cr, and Pb found inA. cruentus, A. dubius, and A. hypochondriacus.2. Materials and Methods2.1. Sampling. Twenty seed samples of 50 g every one werecollected for each plant population (A. hypochondriacus, A.cruentus, and A. dubuis) from south west of San Luis andnorth east of La Pampa provinces (Argentina), during thesummer of 2011-2012. Every complete seed sample was dried,grinded, sieved, and saved into a flask in a dark and fresh placeuntil analysis.2.2. Reagents. Ultrapure nitric acid was purchased fromSigma (St. Louis, MO, USA). All standard solutions were pre-pared using spectroscopic grade (>99.98%) Merck (Darm-stadt, Germany) reagents. Ultrapure water (18.2MΩ cm) wasobtained using a Barnstead Easy-Pure RF compact watersystem (Dubuque, IA, USA).2.3. Sample Preparation. The seed samples of the three plantswere individually ground using a Wiley 3379 series grinder(Swedesboro, NJ, USA) and passed through a sieve (0.50mmdiameter). A portion of powder (2.0 g) was transferred to aporcelain crucible and 5mL of indium solution (500mg L−1)were added as internal standard to evaluate the degree ofrecovery. The mixture was covered with a cap and reduced toashes in a furnace Dalvo (Buenos Aires, Argentina) at 500∘Cfor 6 h.The ashes were dissolved with 5.0mL of concentratednitric acid until the evolution of gases had stopped. Then,the solution was transferred to a 50mL volumetric flask andcompleted to mark with deionized water [15, 16].2.4. Instrumental. As, Cr, and Pb elements and the internalstandard were determined using a Varian ICP-OES modelICP-OES Vista Pro (Palo Alto, CA, USA), with a Czerny-Turner monochromator, holographic diffraction grid, anda VistaChip charge coupled device (CCD) array detector.The operation parameters of the system ICP-OES are listedin Table 1, which were selected based on signal/noise ratio,time of analysis, emission intensity levels, and presence of apossible background effect.2.5. Statistical Analysis. Calibration curves for each elementwere constructed in triplicate using six different concentra-tions, giving regression coefficient (𝑟2) values which rangedfrom 0.9957 to 0.9992.The analysis of amaranth seed samplesTable 1: The operating parameters of the system ICP-OES.Parameter instrument operating conditionsAs Cr Pb𝜆 (nm) As: 188.980 𝜆 (nm) Cr: 205.560 𝜆 (nm) Pb: 220.353Power: 1.2 kWPlasma gas flow: 15 L/minAuxiliary gas flow: 1.5 L/minNebulizer pressure: 250 kPaPump rate: 15 rpmSample uptake rate: 1.2mL/minReplicate read time: 30 sBackground correction FittedReplicate read time: 10 sReplicate readings: 3Table 2: Concentration of As, Cr, and Pb in A. dubius, A. cruentus,and A. hypochondriacus.A. dubius A. cruentus A. hypochondriacusMeana SDb Meana SDb Meana SDbAs 0.76 0.08 <0.5 — <0.5 —Cr 8.19 0.12 1.15 0.08 1.20 0.07Pb 19.04 1.03 30.20 1.25 35.56 1.52aExpressed in mg kg−1 of dried seed.bStandard deviation (𝑛 = 20).was carried out by 20 replicate measurements, and the resultswere expressed as mean ± standard deviation (SD) [2].3. Results and Discussion3.1. Toxic Element Analysis. Table 2 shows the results of theanalysis obtained for the three Amaranthus species. For Pb,high concentrations were found in the 3 species, overcomingthe allowed limit in foods by the World Health Organization(WHO) [17] whose value is 10mg kg−1. Pb concentration ishigher in A. cruentus and A. hypochondriacus, being morethan three times theWHOallowed limit; forA. dubius, the Pbconcentration is twice this limit. Crwas found in the 3 species,but its values are below theWHOallowed limit of 120mg kg−1of vegetable. The concentration of As for A. cruentus, A.hypochondriacus, and A. dubiuswere below 4mg kg−1, whichis the WHO allowed maximum.Toxic elements are present in species of amaranth seedsat different concentrations, which, in some cases, exceededthe permissible levels, such as the case of Pb. This could beattributed to the use of contaminated irrigation water, soil,and the addition of some fertilizers and herbicides. Toxicelements can accumulate in plants through both foliage androot systems.Laidlaw et al. [18] state that urban agriculture presentschallenges in terms of the health of farmers and consumers.Studies have shown that urban soils can receive large inputsof trace metals from different anthropogenic sources butespecially from automobile emissions. Plants growing incontaminated environments can accumulate trace elementsJournal of Chemistry 3Table 3: Results of the validation by standard addition carried outin A. dubius.Initial valuea SDb Addeda Founda RecoveredcAs 0.76 0.08 0.50 1.24 96.0Cr 8.19 0.12 1.15 9.32 98.3Pb 19.04 1.03 3.80 22.96 103.1aMean value and concentration in mg kg−1.bStandard deviation (𝑛 = 20).c[(found-initial)/added] × 100.in high concentrations, causing a serious health risk to con-sumers.Lead is of particular concern because there is increasingevidence that relatively low concentrations of lead in theblood can affect children’s mental development, an effect thatpersists into adulthood. Lead poisoning causes permanentneurological, developmental, and behavioral disorders, par-ticularly in children [18].3.2. Recovery Analysis. To avoid the presence of systematicerror due to sample pretreatment, validation, and recovery,assays were performed. The method of standard addition isconsidered as a validationmethod [19, 20]. Standard additionwas carried out for every toxic element in A. dubius. Table 3presents the results of standard addition, which shows highrecuperation from 96.0–103.1%.On the other hand, an addition of indium as internalstandard serves for evaluating the recovery percentage as wellas the losses in the ashing step [21].The addition of indium was performed prior to the min-eralization step and themean recovery value was 102.3±1.3%(𝑛 = 10), which is in agreement with data from a previousreport [22].To guarantee the absence of systematic errors into the lab-oratory (by operator, instruments, etc.), blind quality control(QC) test sampleswere intercalated to the real samples, whichwere prepared with known concentrations of As, Cr, Pb, andIn but unknown for the operator.One QC sample was included every 10 real samples.The results showed recoveries from 95 to 102% for blindQC samples, indicating absence of systematic error into delaboratory. The limits of detection (LOD) obtained for As,Cr, and Pb were 0.15, 0.23, and 0.57mg kg−1 of dried seed,respectively.4. ConclusionsThis paper discussed the presence of toxic elements in threeamaranth species. Based on results obtained and since thebioconcentration ability of amaranth for severalmetals is wellknown, as well as the fact that if amaranth is consumed it canbe harmful for the human health, it is advisable to analyze thepresence of Pb in amaranth seeds previous to consumption.These levels of Pb indicate that amaranth seed are toxic forthe human beings. Regarding other toxic elements present inthese species, As and Cr were found in low concentrations;their analysis is also advised, mainly in polluted zones orregions under risk ofmetal contamination, to ensure that theyare under the allowed limits.The results presented here can be seen as a basis forfurther study in relation to phyto-remediation of contami-nated soils and should make known on the need to use non-contaminated areas for the cultivation of these species ofamaranth.AcknowledgmentsTheauthors wish to thank the financial support from theUni-versidad Nacional de San Luis, Universidad Nacional de LaPampa, and Consejo Nacional de Investigaciones Cient́ıficasy Técnicas (CONICET).References[1] T. Abe, M. Fukami, and M. Ogasawara, “Cadmium accumula-tion in the shoots and roots of 93 weed species,” Soil Science andPlant Nutrition, vol. 54, no. 4, pp. 566–573, 2008.[2] Q. Li, S. Cai, C. Mo, B. Chu, L. Peng, and F. Yang, “Toxic effectsof heavymetals and their accumulation in vegetables grown in asaline soil,” Ecotoxicology and Environmental Safety, vol. 73, no.1, pp. 84–88, 2010.[3] E. Olivares and E. Pena, “Bioconcentration of mineral elementsin amaranthus dubius (wild spinach, imbuya) growing wildin crops from Miranda state, Venezuela, and used as food,”Interciencia, vol. 34, no. 9, pp. 604–611, 2009.[4] C. M. Onyango, S. I. Shibairo, J. K. Imungi, and J. Harbinson,“The physico-chemical characteristics and some nutritionalvalues of vegetable amaranth sold in Nairobi-Kenya,” Ecologyof Food and Nutrition, vol. 47, no. 4, pp. 382–398, 2008.[5] V. Pillay and S. B. Jonnalagadda, “Elemental uptake by edibleherbs and lettuce (Latuca sativa),” Journal of EnvironmentalScience and Health B, vol. 42, no. 4, pp. 423–428, 2007.[6] F. Rahman, Z. Chen, and R. Naidu, “A comparative study of theextractability of arsenic species from silverbeet and amaranthvegetables,” Environmental Geochemistry andHealth, vol. 31, no.1, pp. 103–113, 2009.[7] E. T. Tyokumbur and T. Okorie, “Bioconcentration of tracemetals in the tissues of two leafy vegetables widely consumedin South West Nigeria,” Biological Trace Element Research, vol.140, no. 2, pp. 215–224, 2011.[8] O. O. Dosumu, N. Salami, and F. A. Adekola, “Comparativestudy of trace element levels in some local vegetable varietiesand irrigationwaters from different locations in Ilorin, Nigeria,”Bulletin of the Chemical Society of Ethiopia, vol. 17, no. 1, pp. 107–112, 2003.[9] A. M. A. van der Walt, D. T. B. Loots, M. I. M. A. Ibrahim, andC. C. Bezuidenhout, “Minerals, trace elements and antioxidantphytochemicals in Wild African dark-green leafy vegetables(morogo),” South African Journal of Science, vol. 105, no. 11-12,pp. 444–448, 2009.[10] M. del Rı́o, R. Font, C. Almela, D. Vélez, R. Montoro, andA. de Haro Bailón, “Heavy metals and arsenic uptake by wildvegetation in the Guadiamar river area after the toxic spill ofthe Aznalcóllar mine,” Journal of Biotechnology, vol. 98, no. 1,pp. 125–137, 2002.[11] M. del Rı́o, F. Ferchaud, R. Font, and A. de Haro, “Field trialsof wild plant species growing in polluted soils of the guadiamarriver area for phytoremediation purposes,” Fresenius Environ-mental Bulletin, vol. 13, no. 11, pp. 1197–1203, 2004.4 Journal of Chemistry[12] M. N. Tijani, “Contamination of shallow groundwater systemand soil-plant transfer of trace metals under amended irrigatedfields,” Agricultural Water Management, vol. 96, no. 3, pp. 437–444, 2009.[13] G. Nabulo, S. D. Young, and C. R. Black, “Assessing risk tohuman health from tropical leafy vegetables grown on contam-inated urban soils,” Science of the Total Environment, vol. 408,no. 22, pp. 5338–5351, 2010.[14] X. Zhang, S. Zhang, X. Xu et al., “Tolerance and accumulationcharacteristics of cadmium in Amaranthus hybridus L,” Journalof Hazardous Materials, vol. 180, no. 1–3, pp. 303–308, 2010.[15] A. A. K. Abou-Arab and M. A. Abou Donia, “Heavy metals inegyptian spices andmedicinal plants and the effect of processingon their levels,” Journal of Agricultural and Food Chemistry, vol.48, no. 6, pp. 2300–2304, 2000.[16] A. Maiga, D. Diallo, R. Bye, and B. S. Paulsen, “Determinationof some toxic and essential metal ions in medicinal and edibleplants from Mali,” Journal of Agricultural and Food Chemistry,vol. 53, no. 6, pp. 2316–2321, 2005.[17] World Health Organization, Guidelines for the Assessment ofHerbal Medicines, WHO, Munich, Germany, 1991.[18] M. A. S. Laidlaw, H. W. Mielke, G. M. Filippelli, D. L. Johnson,and C. R. Gonzales, “Seasonality and children’s blood leadlevels: Developing a predictive model using climatic variablesand blood lead data from Indianapolis, Indiana, Syracuse,New York, and New Orleans, Louisiana (USA),” EnvironmentalHealth Perspectives, vol. 113, no. 6, pp. 793–800, 2005.[19] E. Prichard, G. M. Mackay, and J. Points, Trace Analysis: AStructures Approach to Obtaining Reliable Results, The RoyalSociety of Chemistry, London, UK, 1996.[20] M. R. Gómez, S. Cerutti, L. L. Sombra, M. F. Silva, and L.D. Mart́ınez, “Determination of heavy metals for the qualitycontrol in argentinian herbal medicines by ETAAS and ICP-OES,” Food and Chemical Toxicology, vol. 45, no. 6, pp. 1060–1064, 2007.[21] D. Kara, “Evaluation of trace metal concentrations in someherbs and herbal teas by principal component analysis,” FoodChemistry, vol. 114, no. 1, pp. 347–354, 2009.[22] M. M. Aly, M. N. Al-Seeni, S. Y. Qusti, and N. M. El-Sawi,“Mineral content and microbiological examination of somewhite cheese in Jeddah, Saudi Arabia during summer 2008,”Food and Chemical Toxicology, vol. 48, no. 11, pp. 3031–3034,2010.Submit your manuscripts athttp://www.hindawi.com Chromatography  Research InternationalHindawi Publishing Corporationhttp://www.hindawi.com Volume 2013Hindawi Publishing Corporationhttp://www.hindawi.com Volume 2013Carbohydrate ChemistryInternational Journal ofHindawi Publishing Corporationhttp://www.hindawi.comInternational Journal of Analytical ChemistryVolume 2013ISRN ChromatographyHindawi Publishing Corporationhttp://www.hindawi.com Volume 2013Hindawi Publishing Corporation http://www.hindawi.com Volume 2013The Scientific World JournalHindawi Publishing Corporationhttp://www.hindawi.com Volume 2013Bioinorganic Chemistry and Applications Hindawi Publishing Corporationhttp://www.hindawi.com Volume 2013Journal ofSPECTROSCOPYISRN Analytical Chemistry Hindawi Publishing Corporationhttp://www.hindawi.com Volume 2013ElectrochemistryInternational Journal ofHindawi Publishing Corporation http://www.hindawi.com Volume 2013Hindawi Publishing Corporationhttp://www.hindawi.com Volume 2013Advances inPhysical ChemistryISRN Physical Chemistry Hindawi Publishing Corporationhttp://www.hindawi.com Volume 2013SpectroscopyInternational Journal ofHindawi Publishing Corporationhttp://www.hindawi.com Volume 2013ISRN Inorganic ChemistryHindawi Publishing Corporationhttp://www.hindawi.com Volume 2013Hindawi Publishing Corporationhttp://www.hindawi.com Volume 2013Journal ofChemistryHindawi Publishing Corporationhttp://www.hindawi.com Volume 2013Inorganic Chemistry International Journal ofHindawi Publishing Corporation http://www.hindawi.com Volume 2013 International Journal ofPhotoenergyHindawi Publishing Corporationhttp://www.hindawi.comAnalytical Methods in ChemistryJournal ofVolume 2013ISRN Organic ChemistryHindawi Publishing Corporationhttp://www.hindawi.com Volume 2013Hindawi Publishing Corporationhttp://www.hindawi.com Volume 2013CatalystsJournal of

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Study and determination of As, Cr and Pb in amaranth seeds

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Hindawi Publishing CorporationJournal of ChemistryVolume 2013, Article ID 138391, 4 pageshttp://dx.doi.org/10.1155/2013/138391Research ArticleStudy and Determination of As, Cr, and Pb in Amaranth SeedsElba Graciela Aguilar,1 Miguel Angel Cantarelli,2,3 Eduardo Jorge Marchevsky,4Nora Lilian Escudero,1 and José Manuel Camiña2,31 Facultad de Quı´mica, Bioquı´mica y Farmacia, Universidad Nacional de San Luis, Chacabuco y Pedernera, 5700 San Luis, Argentina2 Facultad de Ciencias Exactas y Naturales, Universidad Nacional de La Pampa, Avenida Uruguay 151,Santa Rosa, 6300 La Pampa, Argentina3 Instituto de Ciencias de la Tierra y Ambientales de La Pampa (INCITAP), Avenida Uruguay 151 Santa Rosa,6300 La Pampa, Argentina4 Instituto de Quı´mica San Luis (INQUISAL), Chacabuco y Pedernera, 5700 San Luis, ArgentinaCorrespondence should be addressed to Miguel Angel Cantarelli; miguelcantarelli@yahoo.com.arReceived 8 May 2013; Revised 4 July 2013; Accepted 7 July 2013Academic Editor: Theocharis C. StamatatosCopyright © 2013 Elba Graciela Aguilar et al. This is an open access article distributed under the Creative Commons AttributionLicense, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properlycited.The concentration of As, Cr, and Pb toxic elements was determined in three species of amaranth seeds: A. hypochondriacus, A.cruentus, andA. dubius.Thedeterminationswere carried out by inductively coupled plasma optical atomic spectroscopy (ICP-OES).The result shows thatCr andAswere found inminor concentrations than allowed by theWorldHealthOrganization (WHO; 120 and4mg kg−1 resp.); As (mg kg−1): A. dubius (0.76) A. cruentus (<0.50) and A. hypochondriacus (<0.50); Cr (mg kg−1): A. dubius (8.19)A. cruentus (1.15) and A. hypochondriacus (1.20). However, the concentration of Pb was high: A. dubius (19.04) A. cruentus (30.20)and A. hypochondriacus (35.56) more than the maximum ofWHO (10mg kg−1). To avoid systematic error, recovery and validationstudies were performed: recovery test: 102.3%; validation (by standard addition): 96.0–103.1%. Due to the fact that amaranth hadbeen proposed as new food due to its nutraceutical properties, the high concentration of Pb found in this study indicates that Pbshould be evaluated in these amaranth species to avoid the intake of toxic element by human beings.1. IntroductionAmaranth is a plant species that was frequently used inAmerica before the Spanish conquest. Then, this crop wasno longer consumed and amaranth was forgotten. From atotal of 70 species belonging to the Amaranthus genus, 40 arefrom America. At present, amaranth is studied as food dueto its high protein content, its excellent amino acid profile,and nutraceutical properties. It is known that amaranth canconcentrate heavymetals and there are numerous reports thatshow this ability: a previous work reported the accumulationof Cd inAmaranthus in both shoot and root ofA. hybridus,A.spinosus, A. viridis, and A. rudis [1]. Other authors reportedthe effect and accumulation of heavy metals by amaranthin saline soils [2]. Also, the ability of Amaranthus dubiusand Amaranthus hybridus to bioconcentrate several mineralelements was proved [3]. Iron, lead, and zinc concentrationswere studied in amaranth plants from Kenya [4].The contentof several metals, such as Al, Fe, Ni, Cr, and Pb, was deter-mined in amaranth [5]. Both the effect of As in the growthof amaranth plants and a new method for the extraction ofAs from the plants were reported [6]. In Nigeria, both, thebioconcentration of trace elements in leaves of Amaranthuscaudatus [7] as well as the study of trace elements inAmaranthus hybridus [8] were carried out. On the otherhand, trace elements were analyzed in leaves of Amaranthushybridus from Africa [9]. The uptake of As and heavy metalsby native Amaranthus blitoides was studied in Spain [10];as a result, the use of Amaranthus albus and Amaranthusblitoides was proposed for bioremediation in contaminatedzones [11].Amaranthus hybriduswas studied due to its poten-tial danger of bioaccumulation of toxic trace metals underbiosolid amended irrigated soils if plants are used as ediblevegetables [12]. A recent report [13] reveals that the intakeof Amaranthus lividus, hybridus, and dubius harvested fromcontaminated soils may be dangerous to human health due2 Journal of Chemistryto their ability to accumulate metals. The Cd accumulationability of A. hybridus, showing high bioconcentration factorsin soil culture and hydroponic solution [14]was also reported.Amaranth seeds have very important nutritional proper-ties and they are very frequently used to obtain flours. Thepreviously mentioned reports studied the concentration ofseveral transition elements in leaves and roots of differentspecies ofAmaranthus although toxic elements have not beenpreviously studied in their seeds.Due to the toxic effect of this plant for intake and also toits negative effect for human health, this paper discusses theconcentration of the toxic elements: As, Cr, and Pb found inA. cruentus, A. dubius, and A. hypochondriacus.2. Materials and Methods2.1. Sampling. Twenty seed samples of 50 g every one werecollected for each plant population (A. hypochondriacus, A.cruentus, and A. dubuis) from south west of San Luis andnorth east of La Pampa provinces (Argentina), during thesummer of 2011-2012. Every complete seed sample was dried,grinded, sieved, and saved into a flask in a dark and fresh placeuntil analysis.2.2. Reagents. Ultrapure nitric acid was purchased fromSigma (St. Louis, MO, USA). All standard solutions were pre-pared using spectroscopic grade (>99.98%) Merck (Darm-stadt, Germany) reagents. Ultrapure water (18.2MΩ cm) wasobtained using a Barnstead Easy-Pure RF compact watersystem (Dubuque, IA, USA).2.3. Sample Preparation. The seed samples of the three plantswere individually ground using a Wiley 3379 series grinder(Swedesboro, NJ, USA) and passed through a sieve (0.50mmdiameter). A portion of powder (2.0 g) was transferred to aporcelain crucible and 5mL of indium solution (500mg L−1)were added as internal standard to evaluate the degree ofrecovery. The mixture was covered with a cap and reduced toashes in a furnace Dalvo (Buenos Aires, Argentina) at 500∘Cfor 6 h.The ashes were dissolved with 5.0mL of concentratednitric acid until the evolution of gases had stopped. Then,the solution was transferred to a 50mL volumetric flask andcompleted to mark with deionized water [15, 16].2.4. Instrumental. As, Cr, and Pb elements and the internalstandard were determined using a Varian ICP-OES modelICP-OES Vista Pro (Palo Alto, CA, USA), with a Czerny-Turner monochromator, holographic diffraction grid, anda VistaChip charge coupled device (CCD) array detector.The operation parameters of the system ICP-OES are listedin Table 1, which were selected based on signal/noise ratio,time of analysis, emission intensity levels, and presence of apossible background effect.2.5. Statistical Analysis. Calibration curves for each elementwere constructed in triplicate using six different concentra-tions, giving regression coefficient (𝑟2) values which rangedfrom 0.9957 to 0.9992.The analysis of amaranth seed samplesTable 1: The operating parameters of the system ICP-OES.Parameter instrument operating conditionsAs Cr Pb𝜆 (nm) As: 188.980 𝜆 (nm) Cr: 205.560 𝜆 (nm) Pb: 220.353Power: 1.2 kWPlasma gas flow: 15 L/minAuxiliary gas flow: 1.5 L/minNebulizer pressure: 250 kPaPump rate: 15 rpmSample uptake rate: 1.2mL/minReplicate read time: 30 sBackground correction FittedReplicate read time: 10 sReplicate readings: 3Table 2: Concentration of As, Cr, and Pb in A. dubius, A. cruentus,and A. hypochondriacus.A. dubius A. cruentus A. hypochondriacusMeana SDb Meana SDb Meana SDbAs 0.76 0.08 <0.5 — <0.5 —Cr 8.19 0.12 1.15 0.08 1.20 0.07Pb 19.04 1.03 30.20 1.25 35.56 1.52aExpressed in mg kg−1 of dried seed.bStandard deviation (𝑛 = 20).was carried out by 20 replicate measurements, and the resultswere expressed as mean ± standard deviation (SD) [2].3. Results and Discussion3.1. Toxic Element Analysis. Table 2 shows the results of theanalysis obtained for the three Amaranthus species. For Pb,high concentrations were found in the 3 species, overcomingthe allowed limit in foods by the World Health Organization(WHO) [17] whose value is 10mg kg−1. Pb concentration ishigher in A. cruentus and A. hypochondriacus, being morethan three times theWHOallowed limit; forA. dubius, the Pbconcentration is twice this limit. Crwas found in the 3 species,but its values are below theWHOallowed limit of 120mg kg−1of vegetable. The concentration of As for A. cruentus, A.hypochondriacus, and A. dubiuswere below 4mg kg−1, whichis the WHO allowed maximum.Toxic elements are present in species of amaranth seedsat different concentrations, which, in some cases, exceededthe permissible levels, such as the case of Pb. This could beattributed to the use of contaminated irrigation water, soil,and the addition of some fertilizers and herbicides. Toxicelements can accumulate in plants through both foliage androot systems.Laidlaw et al. [18] state that urban agriculture presentschallenges in terms of the health of farmers and consumers.Studies have shown that urban soils can receive large inputsof trace metals from different anthropogenic sources butespecially from automobile emissions. Plants growing incontaminated environments can accumulate trace elementsJournal of Chemistry 3Table 3: Results of the validation by standard addition carried outin A. dubius.Initial valuea SDb Addeda Founda RecoveredcAs 0.76 0.08 0.50 1.24 96.0Cr 8.19 0.12 1.15 9.32 98.3Pb 19.04 1.03 3.80 22.96 103.1aMean value and concentration in mg kg−1.bStandard deviation (𝑛 = 20).c[(found-initial)/added] × 100.in high concentrations, causing a serious health risk to con-sumers.Lead is of particular concern because there is increasingevidence that relatively low concentrations of lead in theblood can affect children’s mental development, an effect thatpersists into adulthood. Lead poisoning causes permanentneurological, developmental, and behavioral disorders, par-ticularly in children [18].3.2. Recovery Analysis. To avoid the presence of systematicerror due to sample pretreatment, validation, and recovery,assays were performed. The method of standard addition isconsidered as a validationmethod [19, 20]. Standard additionwas carried out for every toxic element in A. dubius. Table 3presents the results of standard addition, which shows highrecuperation from 96.0–103.1%.On the other hand, an addition of indium as internalstandard serves for evaluating the recovery percentage as wellas the losses in the ashing step [21].The addition of indium was performed prior to the min-eralization step and themean recovery value was 102.3±1.3%(𝑛 = 10), which is in agreement with data from a previousreport [22].To guarantee the absence of systematic errors into the lab-oratory (by operator, instruments, etc.), blind quality control(QC) test sampleswere intercalated to the real samples, whichwere prepared with known concentrations of As, Cr, Pb, andIn but unknown for the operator.One QC sample was included every 10 real samples.The results showed recoveries from 95 to 102% for blindQC samples, indicating absence of systematic error into delaboratory. The limits of detection (LOD) obtained for As,Cr, and Pb were 0.15, 0.23, and 0.57mg kg−1 of dried seed,respectively.4. ConclusionsThis paper discussed the presence of toxic elements in threeamaranth species. Based on results obtained and since thebioconcentration ability of amaranth for severalmetals is wellknown, as well as the fact that if amaranth is consumed it canbe harmful for the human health, it is advisable to analyze thepresence of Pb in amaranth seeds previous to consumption.These levels of Pb indicate that amaranth seed are toxic forthe human beings. Regarding other toxic elements present inthese species, As and Cr were found in low concentrations;their analysis is also advised, mainly in polluted zones orregions under risk ofmetal contamination, to ensure that theyare under the allowed limits.The results presented here can be seen as a basis forfurther study in relation to phyto-remediation of contami-nated soils and should make known on the need to use non-contaminated areas for the cultivation of these species ofamaranth.AcknowledgmentsTheauthors wish to thank the financial support from theUni-versidad Nacional de San Luis, Universidad Nacional de LaPampa, and Consejo Nacional de Investigaciones Cient´ıficasy Te´cnicas (CONICET).References[1] T. Abe, M. Fukami, and M. Ogasawara, “Cadmium accumula-tion in the shoots and roots of 93 weed species,” Soil Science andPlant Nutrition, vol. 54, no. 4, pp. 566–573, 2008.[2] Q. Li, S. Cai, C. Mo, B. Chu, L. Peng, and F. Yang, “Toxic effectsof heavymetals and their accumulation in vegetables grown in asaline soil,” Ecotoxicology and Environmental Safety, vol. 73, no.1, pp. 84–88, 2010.[3] E. Olivares and E. Pena, “Bioconcentration of mineral elementsin amaranthus dubius (wild spinach, imbuya) growing wildin crops from Miranda state, Venezuela, and used as food,”Interciencia, vol. 34, no. 9, pp. 604–611, 2009.[4] C. M. Onyango, S. I. Shibairo, J. K. Imungi, and J. Harbinson,“The physico-chemical characteristics and some nutritionalvalues of vegetable amaranth sold in Nairobi-Kenya,” Ecologyof Food and Nutrition, vol. 47, no. 4, pp. 382–398, 2008.[5] V. Pillay and S. B. Jonnalagadda, “Elemental uptake by edibleherbs and lettuce (Latuca sativa),” Journal of EnvironmentalScience and Health B, vol. 42, no. 4, pp. 423–428, 2007.[6] F. Rahman, Z. Chen, and R. Naidu, “A comparative study of theextractability of arsenic species from silverbeet and amaranthvegetables,” Environmental Geochemistry andHealth, vol. 31, no.1, pp. 103–113, 2009.[7] E. T. Tyokumbur and T. Okorie, “Bioconcentration of tracemetals in the tissues of two leafy vegetables widely consumedin South West Nigeria,” Biological Trace Element Research, vol.140, no. 2, pp. 215–224, 2011.[8] O. O. Dosumu, N. Salami, and F. A. Adekola, “Comparativestudy of trace element levels in some local vegetable varietiesand irrigationwaters from different locations in Ilorin, Nigeria,”Bulletin of the Chemical Society of Ethiopia, vol. 17, no. 1, pp. 107–112, 2003.[9] A. M. A. van der Walt, D. T. B. Loots, M. I. M. A. Ibrahim, andC. C. Bezuidenhout, “Minerals, trace elements and antioxidantphytochemicals in Wild African dark-green leafy vegetables(morogo),” South African Journal of Science, vol. 105, no. 11-12,pp. 444–448, 2009.[10] M. del Rı´o, R. Font, C. Almela, D. Ve´lez, R. Montoro, andA. de Haro Bailo´n, “Heavy metals and arsenic uptake by wildvegetation in the Guadiamar river area after the toxic spill ofthe Aznalco´llar mine,” Journal of Biotechnology, vol. 98, no. 1,pp. 125–137, 2002.[11] M. del Rı´o, F. Ferchaud, R. Font, and A. de Haro, “Field trialsof wild plant species growing in polluted soils of the guadiamarriver area for phytoremediation purposes,” Fresenius Environ-mental Bulletin, vol. 13, no. 11, pp. 1197–1203, 2004.4 Journal of Chemistry[12] M. N. Tijani, “Contamination of shallow groundwater systemand soil-plant transfer of trace metals under amended irrigatedfields,” Agricultural Water Management, vol. 96, no. 3, pp. 437–444, 2009.[13] G. Nabulo, S. D. Young, and C. R. Black, “Assessing risk tohuman health from tropical leafy vegetables grown on contam-inated urban soils,” Science of the Total Environment, vol. 408,no. 22, pp. 5338–5351, 2010.[14] X. Zhang, S. Zhang, X. Xu et al., “Tolerance and accumulationcharacteristics of cadmium in Amaranthus hybridus L,” Journalof Hazardous Materials, vol. 180, no. 1–3, pp. 303–308, 2010.[15] A. A. K. Abou-Arab and M. A. Abou Donia, “Heavy metals inegyptian spices andmedicinal plants and the effect of processingon their levels,” Journal of Agricultural and Food Chemistry, vol.48, no. 6, pp. 2300–2304, 2000.[16] A. Maiga, D. Diallo, R. Bye, and B. S. Paulsen, “Determinationof some toxic and essential metal ions in medicinal and edibleplants from Mali,” Journal of Agricultural and Food Chemistry,vol. 53, no. 6, pp. 2316–2321, 2005.[17] World Health Organization, Guidelines for the Assessment ofHerbal Medicines, WHO, Munich, Germany, 1991.[18] M. A. S. Laidlaw, H. W. Mielke, G. M. Filippelli, D. L. Johnson,and C. R. Gonzales, “Seasonality and children’s blood leadlevels: Developing a predictive model using climatic variablesand blood lead data from Indianapolis, Indiana, Syracuse,New York, and New Orleans, Louisiana (USA),” EnvironmentalHealth Perspectives, vol. 113, no. 6, pp. 793–800, 2005.[19] E. Prichard, G. M. Mackay, and J. Points, Trace Analysis: AStructures Approach to Obtaining Reliable Results, The RoyalSociety of Chemistry, London, UK, 1996.[20] M. R. Go´mez, S. Cerutti, L. L. Sombra, M. F. Silva, and L.D. Mart´ınez, “Determination of heavy metals for the qualitycontrol in argentinian herbal medicines by ETAAS and ICP-OES,” Food and Chemical Toxicology, vol. 45, no. 6, pp. 1060–1064, 2007.[21] D. Kara, “Evaluation of trace metal concentrations in someherbs and herbal teas by principal component analysis,” FoodChemistry, vol. 114, no. 1, pp. 347–354, 2009.[22] M. M. Aly, M. N. Al-Seeni, S. Y. Qusti, and N. M. El-Sawi,“Mineral content and microbiological examination of somewhite cheese in Jeddah, Saudi Arabia during summer 2008,”Food and Chemical Toxicology, vol. 48, no. 11, pp. 3031–3034,2010.Submit your manuscripts athttp://www.hindawi.com Chromatography  Research InternationalHindawi Publishing Corporationhttp://www.hindawi.com Volume 2013Hindawi Publishing Corporationhttp://www.hindawi.com Volume 2013Carbohydrate ChemistryInternational Journal ofHindawi Publishing Corporationhttp://www.hindawi.comInternational Journal of Analytical ChemistryVolume 2013ISRN ChromatographyHindawi Publishing Corporationhttp://www.hindawi.com Volume 2013Hindawi Publishing Corporation http://www.hindawi.com Volume 2013The Scientific World JournalHindawi Publishing Corporationhttp://www.hindawi.com Volume 2013Bioinorganic Chemistry and Applications Hindawi Publishing Corporationhttp://www.hindawi.com Volume 2013Journal ofSPECTROSCOPYISRN Analytical Chemistry Hindawi Publishing Corporationhttp://www.hindawi.com Volume 2013ElectrochemistryInternational Journal ofHindawi Publishing Corporation http://www.hindawi.com Volume 2013Hindawi Publishing Corporationhttp://www.hindawi.com Volume 2013Advances inPhysical ChemistryISRN Physical Chemistry Hindawi Publishing Corporationhttp://www.hindawi.com Volume 2013SpectroscopyInternational Journal ofHindawi Publishing Corporationhttp://www.hindawi.com Volume 2013ISRN Inorganic ChemistryHindawi Publishing Corporationhttp://www.hindawi.com Volume 2013Hindawi Publishing Corporationhttp://www.hindawi.com Volume 2013Journal ofChemistryHindawi Publishing Corporationhttp://www.hindawi.com Volume 2013Inorganic Chemistry International Journal ofHindawi Publishing Corporation http://www.hindawi.com Volume 2013 International Journal ofPhotoenergyHindawi Publishing Corporationhttp://www.hindawi.comAnalytical Methods in ChemistryJournal ofVolume 2013ISRN Organic ChemistryHindawi Publishing Corporationhttp://www.hindawi.com Volume 2013Hindawi Publishing Corporationhttp://www.hindawi.com Volume 2013CatalystsJournal of

The concentration of As, Cr, and Pb toxic elements was determined in three species of amaranth seeds:A. hypochondriacus,A. cruentus, andA. dubius. The determinations were carried out by inductively coupled plasma optical atomic spectroscopy (ICP-OES). The result shows that Cr and As were found in minor concentrations than allowed by the World Health Organization (WHO; 120 and 4 mg kg−1resp.); As (mg kg−1):A. dubius(0.76)A. cruentus(&lt;0.50) andA. hypochondriacus(&lt;0.50); Cr (mg kg−1):A. dubius(8.19)A. cruentus(1.15) andA. hypochondriacus(1.20). However, the concentration of Pb was high:A. dubius(19.04)A. cruentus(30.20) andA. hypochondriacus(35.56) more than the maximum of WHO (10 mg kg−1). To avoid systematic error, recovery and validation studies were performed: recovery test: 102.3%; validation (by standard addition): 96.0–103.1%. Due to the fact that amaranth had been proposed as new food due to its nutraceutical properties, the high concentration of Pb found in this study indicates that Pb should be evaluated in these amaranth species to avoid the intake of toxic element by human beings.</jats:p

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Hindawi Publishing CorporationJournal of ChemistryVolume 2013, Article ID 138391, 4 pageshttp://dx.doi.org/10.1155/2013/138391Research ArticleStudy and Determination of As, Cr, and Pb in Amaranth SeedsElba Graciela Aguilar,1 Miguel Angel Cantarelli,2,3 Eduardo Jorge Marchevsky,4Nora Lilian Escudero,1 and José Manuel Camiña2,31 Facultad de Quı´mica, Bioquı´mica y Farmacia, Universidad Nacional de San Luis, Chacabuco y Pedernera, 5700 San Luis, Argentina2 Facultad de Ciencias Exactas y Naturales, Universidad Nacional de La Pampa, Avenida Uruguay 151,Santa Rosa, 6300 La Pampa, Argentina3 Instituto de Ciencias de la Tierra y Ambientales de La Pampa (INCITAP), Avenida Uruguay 151 Santa Rosa,6300 La Pampa, Argentina4 Instituto de Quı´mica San Luis (INQUISAL), Chacabuco y Pedernera, 5700 San Luis, ArgentinaCorrespondence should be addressed to Miguel Angel Cantarelli; miguelcantarelli@yahoo.com.arReceived 8 May 2013; Revised 4 July 2013; Accepted 7 July 2013Academic Editor: Theocharis C. StamatatosCopyright © 2013 Elba Graciela Aguilar et al. This is an open access article distributed under the Creative Commons AttributionLicense, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properlycited.The concentration of As, Cr, and Pb toxic elements was determined in three species of amaranth seeds: A. hypochondriacus, A.cruentus, andA. dubius.Thedeterminationswere carried out by inductively coupled plasma optical atomic spectroscopy (ICP-OES).The result shows thatCr andAswere found inminor concentrations than allowed by theWorldHealthOrganization (WHO; 120 and4mg kg−1 resp.); As (mg kg−1): A. dubius (0.76) A. cruentus (<0.50) and A. hypochondriacus (<0.50); Cr (mg kg−1): A. dubius (8.19)A. cruentus (1.15) and A. hypochondriacus (1.20). However, the concentration of Pb was high: A. dubius (19.04) A. cruentus (30.20)and A. hypochondriacus (35.56) more than the maximum ofWHO (10mg kg−1). To avoid systematic error, recovery and validationstudies were performed: recovery test: 102.3%; validation (by standard addition): 96.0–103.1%. Due to the fact that amaranth hadbeen proposed as new food due to its nutraceutical properties, the high concentration of Pb found in this study indicates that Pbshould be evaluated in these amaranth species to avoid the intake of toxic element by human beings.1. IntroductionAmaranth is a plant species that was frequently used inAmerica before the Spanish conquest. Then, this crop wasno longer consumed and amaranth was forgotten. From atotal of 70 species belonging to the Amaranthus genus, 40 arefrom America. At present, amaranth is studied as food dueto its high protein content, its excellent amino acid profile,and nutraceutical properties. It is known that amaranth canconcentrate heavymetals and there are numerous reports thatshow this ability: a previous work reported the accumulationof Cd inAmaranthus in both shoot and root ofA. hybridus,A.spinosus, A. viridis, and A. rudis [1]. Other authors reportedthe effect and accumulation of heavy metals by amaranthin saline soils [2]. Also, the ability of Amaranthus dubiusand Amaranthus hybridus to bioconcentrate several mineralelements was proved [3]. Iron, lead, and zinc concentrationswere studied in amaranth plants from Kenya [4].The contentof several metals, such as Al, Fe, Ni, Cr, and Pb, was deter-mined in amaranth [5]. Both the effect of As in the growthof amaranth plants and a new method for the extraction ofAs from the plants were reported [6]. In Nigeria, both, thebioconcentration of trace elements in leaves of Amaranthuscaudatus [7] as well as the study of trace elements inAmaranthus hybridus [8] were carried out. On the otherhand, trace elements were analyzed in leaves of Amaranthushybridus from Africa [9]. The uptake of As and heavy metalsby native Amaranthus blitoides was studied in Spain [10];as a result, the use of Amaranthus albus and Amaranthusblitoides was proposed for bioremediation in contaminatedzones [11].Amaranthus hybriduswas studied due to its poten-tial danger of bioaccumulation of toxic trace metals underbiosolid amended irrigated soils if plants are used as ediblevegetables [12]. A recent report [13] reveals that the intakeof Amaranthus lividus, hybridus, and dubius harvested fromcontaminated soils may be dangerous to human health due2 Journal of Chemistryto their ability to accumulate metals. The Cd accumulationability of A. hybridus, showing high bioconcentration factorsin soil culture and hydroponic solution [14]was also reported.Amaranth seeds have very important nutritional proper-ties and they are very frequently used to obtain flours. Thepreviously mentioned reports studied the concentration ofseveral transition elements in leaves and roots of differentspecies ofAmaranthus although toxic elements have not beenpreviously studied in their seeds.Due to the toxic effect of this plant for intake and also toits negative effect for human health, this paper discusses theconcentration of the toxic elements: As, Cr, and Pb found inA. cruentus, A. dubius, and A. hypochondriacus.2. Materials and Methods2.1. Sampling. Twenty seed samples of 50 g every one werecollected for each plant population (A. hypochondriacus, A.cruentus, and A. dubuis) from south west of San Luis andnorth east of La Pampa provinces (Argentina), during thesummer of 2011-2012. Every complete seed sample was dried,grinded, sieved, and saved into a flask in a dark and fresh placeuntil analysis.2.2. Reagents. Ultrapure nitric acid was purchased fromSigma (St. Louis, MO, USA). All standard solutions were pre-pared using spectroscopic grade (>99.98%) Merck (Darm-stadt, Germany) reagents. Ultrapure water (18.2MΩ cm) wasobtained using a Barnstead Easy-Pure RF compact watersystem (Dubuque, IA, USA).2.3. Sample Preparation. The seed samples of the three plantswere individually ground using a Wiley 3379 series grinder(Swedesboro, NJ, USA) and passed through a sieve (0.50mmdiameter). A portion of powder (2.0 g) was transferred to aporcelain crucible and 5mL of indium solution (500mg L−1)were added as internal standard to evaluate the degree ofrecovery. The mixture was covered with a cap and reduced toashes in a furnace Dalvo (Buenos Aires, Argentina) at 500∘Cfor 6 h.The ashes were dissolved with 5.0mL of concentratednitric acid until the evolution of gases had stopped. Then,the solution was transferred to a 50mL volumetric flask andcompleted to mark with deionized water [15, 16].2.4. Instrumental. As, Cr, and Pb elements and the internalstandard were determined using a Varian ICP-OES modelICP-OES Vista Pro (Palo Alto, CA, USA), with a Czerny-Turner monochromator, holographic diffraction grid, anda VistaChip charge coupled device (CCD) array detector.The operation parameters of the system ICP-OES are listedin Table 1, which were selected based on signal/noise ratio,time of analysis, emission intensity levels, and presence of apossible background effect.2.5. Statistical Analysis. Calibration curves for each elementwere constructed in triplicate using six different concentra-tions, giving regression coefficient (𝑟2) values which rangedfrom 0.9957 to 0.9992.The analysis of amaranth seed samplesTable 1: The operating parameters of the system ICP-OES.Parameter instrument operating conditionsAs Cr Pb𝜆 (nm) As: 188.980 𝜆 (nm) Cr: 205.560 𝜆 (nm) Pb: 220.353Power: 1.2 kWPlasma gas flow: 15 L/minAuxiliary gas flow: 1.5 L/minNebulizer pressure: 250 kPaPump rate: 15 rpmSample uptake rate: 1.2mL/minReplicate read time: 30 sBackground correction FittedReplicate read time: 10 sReplicate readings: 3Table 2: Concentration of As, Cr, and Pb in A. dubius, A. cruentus,and A. hypochondriacus.A. dubius A. cruentus A. hypochondriacusMeana SDb Meana SDb Meana SDbAs 0.76 0.08 <0.5 — <0.5 —Cr 8.19 0.12 1.15 0.08 1.20 0.07Pb 19.04 1.03 30.20 1.25 35.56 1.52aExpressed in mg kg−1 of dried seed.bStandard deviation (𝑛 = 20).was carried out by 20 replicate measurements, and the resultswere expressed as mean ± standard deviation (SD) [2].3. Results and Discussion3.1. Toxic Element Analysis. Table 2 shows the results of theanalysis obtained for the three Amaranthus species. For Pb,high concentrations were found in the 3 species, overcomingthe allowed limit in foods by the World Health Organization(WHO) [17] whose value is 10mg kg−1. Pb concentration ishigher in A. cruentus and A. hypochondriacus, being morethan three times theWHOallowed limit; forA. dubius, the Pbconcentration is twice this limit. Crwas found in the 3 species,but its values are below theWHOallowed limit of 120mg kg−1of vegetable. The concentration of As for A. cruentus, A.hypochondriacus, and A. dubiuswere below 4mg kg−1, whichis the WHO allowed maximum.Toxic elements are present in species of amaranth seedsat different concentrations, which, in some cases, exceededthe permissible levels, such as the case of Pb. This could beattributed to the use of contaminated irrigation water, soil,and the addition of some fertilizers and herbicides. Toxicelements can accumulate in plants through both foliage androot systems.Laidlaw et al. [18] state that urban agriculture presentschallenges in terms of the health of farmers and consumers.Studies have shown that urban soils can receive large inputsof trace metals from different anthropogenic sources butespecially from automobile emissions. Plants growing incontaminated environments can accumulate trace elementsJournal of Chemistry 3Table 3: Results of the validation by standard addition carried outin A. dubius.Initial valuea SDb Addeda Founda RecoveredcAs 0.76 0.08 0.50 1.24 96.0Cr 8.19 0.12 1.15 9.32 98.3Pb 19.04 1.03 3.80 22.96 103.1aMean value and concentration in mg kg−1.bStandard deviation (𝑛 = 20).c[(found-initial)/added] × 100.in high concentrations, causing a serious health risk to con-sumers.Lead is of particular concern because there is increasingevidence that relatively low concentrations of lead in theblood can affect children’s mental development, an effect thatpersists into adulthood. Lead poisoning causes permanentneurological, developmental, and behavioral disorders, par-ticularly in children [18].3.2. Recovery Analysis. To avoid the presence of systematicerror due to sample pretreatment, validation, and recovery,assays were performed. The method of standard addition isconsidered as a validationmethod [19, 20]. Standard additionwas carried out for every toxic element in A. dubius. Table 3presents the results of standard addition, which shows highrecuperation from 96.0–103.1%.On the other hand, an addition of indium as internalstandard serves for evaluating the recovery percentage as wellas the losses in the ashing step [21].The addition of indium was performed prior to the min-eralization step and themean recovery value was 102.3±1.3%(𝑛 = 10), which is in agreement with data from a previousreport [22].To guarantee the absence of systematic errors into the lab-oratory (by operator, instruments, etc.), blind quality control(QC) test sampleswere intercalated to the real samples, whichwere prepared with known concentrations of As, Cr, Pb, andIn but unknown for the operator.One QC sample was included every 10 real samples.The results showed recoveries from 95 to 102% for blindQC samples, indicating absence of systematic error into delaboratory. The limits of detection (LOD) obtained for As,Cr, and Pb were 0.15, 0.23, and 0.57mg kg−1 of dried seed,respectively.4. ConclusionsThis paper discussed the presence of toxic elements in threeamaranth species. Based on results obtained and since thebioconcentration ability of amaranth for severalmetals is wellknown, as well as the fact that if amaranth is consumed it canbe harmful for the human health, it is advisable to analyze thepresence of Pb in amaranth seeds previous to consumption.These levels of Pb indicate that amaranth seed are toxic forthe human beings. Regarding other toxic elements present inthese species, As and Cr were found in low concentrations;their analysis is also advised, mainly in polluted zones orregions under risk ofmetal contamination, to ensure that theyare under the allowed limits.The results presented here can be seen as a basis forfurther study in relation to phyto-remediation of contami-nated soils and should make known on the need to use non-contaminated areas for the cultivation of these species ofamaranth.AcknowledgmentsTheauthors wish to thank the financial support from theUni-versidad Nacional de San Luis, Universidad Nacional de LaPampa, and Consejo Nacional de Investigaciones Cient´ıficasy Te´cnicas (CONICET).References[1] T. Abe, M. Fukami, and M. Ogasawara, “Cadmium accumula-tion in the shoots and roots of 93 weed species,” Soil Science andPlant Nutrition, vol. 54, no. 4, pp. 566–573, 2008.[2] Q. Li, S. Cai, C. Mo, B. Chu, L. Peng, and F. Yang, “Toxic effectsof heavymetals and their accumulation in vegetables grown in asaline soil,” Ecotoxicology and Environmental Safety, vol. 73, no.1, pp. 84–88, 2010.[3] E. Olivares and E. Pena, “Bioconcentration of mineral elementsin amaranthus dubius (wild spinach, imbuya) growing wildin crops from Miranda state, Venezuela, and used as food,”Interciencia, vol. 34, no. 9, pp. 604–611, 2009.[4] C. M. Onyango, S. I. Shibairo, J. K. Imungi, and J. Harbinson,“The physico-chemical characteristics and some nutritionalvalues of vegetable amaranth sold in Nairobi-Kenya,” Ecologyof Food and Nutrition, vol. 47, no. 4, pp. 382–398, 2008.[5] V. Pillay and S. B. Jonnalagadda, “Elemental uptake by edibleherbs and lettuce (Latuca sativa),” Journal of EnvironmentalScience and Health B, vol. 42, no. 4, pp. 423–428, 2007.[6] F. Rahman, Z. Chen, and R. Naidu, “A comparative study of theextractability of arsenic species from silverbeet and amaranthvegetables,” Environmental Geochemistry andHealth, vol. 31, no.1, pp. 103–113, 2009.[7] E. T. Tyokumbur and T. Okorie, “Bioconcentration of tracemetals in the tissues of two leafy vegetables widely consumedin South West Nigeria,” Biological Trace Element Research, vol.140, no. 2, pp. 215–224, 2011.[8] O. O. Dosumu, N. Salami, and F. A. Adekola, “Comparativestudy of trace element levels in some local vegetable varietiesand irrigationwaters from different locations in Ilorin, Nigeria,”Bulletin of the Chemical Society of Ethiopia, vol. 17, no. 1, pp. 107–112, 2003.[9] A. M. A. van der Walt, D. T. B. Loots, M. I. M. A. Ibrahim, andC. C. Bezuidenhout, “Minerals, trace elements and antioxidantphytochemicals in Wild African dark-green leafy vegetables(morogo),” South African Journal of Science, vol. 105, no. 11-12,pp. 444–448, 2009.[10] M. del Rı´o, R. Font, C. Almela, D. Ve´lez, R. 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Study and determination of As, Cr and Pb in amaranth seeds

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