<?xml version="1.0" encoding="ISO-8859-1"?><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<front>
<journal-meta>
<journal-id>1659-4266</journal-id>
<journal-title><![CDATA[Cuadernos de Investigación UNED]]></journal-title>
<abbrev-journal-title><![CDATA[Cuadernos de Investigación UNED]]></abbrev-journal-title>
<issn>1659-4266</issn>
<publisher>
<publisher-name><![CDATA[Universidad Estatal a Distancia de Costa Rica]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S1659-42662022000100005</article-id>
<article-id pub-id-type="doi">10.22458/urj.v14i1.3485</article-id>
<title-group>
<article-title xml:lang="es"><![CDATA[Validación de un método analítico con ácidos de menor pureza, y matrices de hierro, para la evaluación de metales pesados (Cd, Pb, Cr y As) en fertilizantes]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Elizondo Hidalgo]]></surname>
<given-names><![CDATA[Fabricio]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Pérez López]]></surname>
<given-names><![CDATA[Esteban]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
</contrib-group>
<aff id="Af1">
<institution><![CDATA[,Universidad de Costa Rica Sede de Occidente Recinto de Grecia]]></institution>
<addr-line><![CDATA[Grecia ]]></addr-line>
<country>Costa Rica</country>
</aff>
<aff id="Af2">
<institution><![CDATA[,Universidad de Costa Rica Sede de Occidente Recinto de Grecia]]></institution>
<addr-line><![CDATA[Grecia ]]></addr-line>
<country>Costa Rica</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>06</month>
<year>2022</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>06</month>
<year>2022</year>
</pub-date>
<volume>14</volume>
<numero>1</numero>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://www.scielo.sa.cr/scielo.php?script=sci_arttext&amp;pid=S1659-42662022000100005&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.sa.cr/scielo.php?script=sci_abstract&amp;pid=S1659-42662022000100005&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.sa.cr/scielo.php?script=sci_pdf&amp;pid=S1659-42662022000100005&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="es"><p><![CDATA[RESUMEN Introducción: El uso frecuente de fertilizantes en el sector agrícola costarricense provoca contaminación ambiental; y los metales pesados se encuentran entre los principales contaminantes debido a su alta toxicidad, lo que fortalece la necesidad de métodos locales asequibles y confiables para evaluar los niveles de contaminación. Objetivo: Validar una adaptación de un método que utiliza pureza de ácido modificada y matrices de hierro para medir metales pesados (Cd, Pb, Cr y As) en fertilizantes. Método: Probamos cuatro análisis por duplicado de una muestra de concentración conocida con ácidos de grado reactivo y ácidos ultrapuros. Para la prueba de interferencia de hierro, usamos ocho repeticiones. También hicimos pruebas de sesgo, precisión, límites de detección, límite de cuantificación, especificidad, recuperación, falsos positivos y falsos negativos. Resultados: El nuevo método demostró ser satisfactorio y su eficacia se confirmó con los parámetros de rendimiento analítico. Conclusiones: El método es resistente a cambios en la pureza del ácido y tolera matrices con concentraciones de hierro menores al 5% m/m.]]></p></abstract>
<abstract abstract-type="short" xml:lang="en"><p><![CDATA[ABSTRACT ''Validation of an analytical method with modified acid purity and iron matrices to measure heavy metals (Cd, Pb, Cr and As) in fertilizers''. Introduction: The frequent use of fertilizers in the Costa Rican agricultural sector causes environmental pollution; and heavy metals are among the main pollutants because of their high toxicity, strengthening the need for affordable and reliable local methods to assess pollution levels. Objective: To validate an adaptation of a method that uses modified acid purity and iron matrices to measure heavy metals (Cd, Pb, Cr and As) in fertilizers. Method: We tested four duplicate analyzes of a sample of known concentration with reactive grade acids and ultra-pure acids. For the iron interference test, we used eight replicates. We also did tests for bias, precision, detection limits, quantification limit, specificity, recovery, false positives and false negatives. Results: The new method proved satisfactory and its efficiency held by analytical performance parameters. Conclusions: The method is resistant to changes in acid purity, and tolerates matrices with iron concentrations under 5% m/m.]]></p></abstract>
<kwd-group>
<kwd lng="en"><![CDATA[Heavy metals]]></kwd>
<kwd lng="en"><![CDATA[fertilizer]]></kwd>
<kwd lng="en"><![CDATA[agrochemicals]]></kwd>
<kwd lng="en"><![CDATA[validation]]></kwd>
<kwd lng="en"><![CDATA[ICP]]></kwd>
<kwd lng="es"><![CDATA[Metales pesados]]></kwd>
<kwd lng="es"><![CDATA[fertilizante]]></kwd>
<kwd lng="es"><![CDATA[agroquímicos]]></kwd>
<kwd lng="es"><![CDATA[validación]]></kwd>
<kwd lng="es"><![CDATA[ICP]]></kwd>
</kwd-group>
</article-meta>
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