Use of SEC–ICP–MS with a collision cell for determining the interaction of chromium with DNA extracted from metal-contaminated soils

APORTES Y DIFICULTADES DE LA METAGENÓMICA DE SUELOS Y SU IMPACTO EN LA AGRICULTURA

Los microorganismos son de gran interés porque colonizan todo tipo de ambiente, sin embargo, uno de los problemas al que nos enfrentamos para conocer su diversidad biológica es que no todos los microorganismos son cultivables. El desarrollo de nuevas tecnologías como la generación de vectores de clonación aunado al desarrollo de técnicas de secuenciación de alto rendimiento ha favorecido el surgimiento de una nueva herramienta llamada metagenómica, la cual nos permite estudiar genomas de comunidades enteras de microorganismos. Debido a que ningún ambiente es idéntico a otro, es importante mencionar que dependiendo del tipo de muestra a analizar será el tipo de reto al cual nos enfrentaremos al trabajar con metagenómica, en el caso específico del suelo existen diversas variantes como la contaminación del suelo con metales pesados o diversos compuestos químicos que podrían limitar los estudios. Sin embargo, pese a las limitaciones que el mismo ambiente presenta, la metagenómica ha permitido tanto el descubrimiento de nuevos genes como la caracterización de las comunidades microbianas que influyen positivamente en el desarrollo de plantas, lo cual en un futuro podría generar un gran impacto en la agricultura. En este artículo se realizó una revisión de diversas investigaciones que han empleado metagenómica, reportadas en las bases de datos de PudMed y Google Schoolar, con el objetivo de examinar los beneficios y limitaciones de las diversas metodologías empleadas en el tratamiento del ADN metagenómico de suelo y el impacto de la metagenómica en la agricultura.

Development of a novel, fast, sensitive method for chromium speciation in wastewater based on an organic polymer as solid phase extraction material combined with HPLC-ICP-MS

Speciation analysis of inorganic chromium in wastewater is of great significance for the monitoring of environmental pollution. In this work, N,N-bis(2-aminoethyl)ethane-1,2-diamine functionalized poly(chloromethyl styrene-co-styrene) was synthesized, characterized and used as the adsorbent to preconcentrate chromium species in environmental waters by on line solid-phase extraction (SPE). The trace speciation analysis of Cr(III) and Cr(VI) in wastewater has been used by short-column high-performance liquid chromatography hyphenated to inductively coupled plasma spectrometry (HPLC-ICP-MS) after on-line SPE. Cr(III) and Cr(VI) have been adsorbed on the anion exchange column after transforming the cationic Cr(III) to an anionic [Cr(III)-EDTA](-) complex devoid of re-dox reagent, and then eluted rapidly (within seconds) with a very low concentration of tetrabutylammonium hydroxide (TBAH) solution. This method provides a reliable on-line preconcentration method and detection coupled technique. Under the optimized conditions, high enrichment factors have been obtained for Cr(VI) and [Cr(III)-EDTA](-) with 30mL sample solution up to 105 and 128, respectively. The low detection limits of 0.0068ng mL(-1) and 0.0041ng mL(-1), with the relative standard deviations (RSDs) of 4.3% and 3.6% were obtained for Cr(VI) and [Cr(III)-EDTA](-), respectively. The developed method was validated by analyzing Certified Reference Materials GSBZ50027-94, and the spike tests were also performed. At the same time, thanks to the merit of simple operation, rapid adsorption/desorption dynamics, high enrichment and low LODs, the established method was applied to analyze three wastewater samples from different discharge port.

Inductively coupled plasma-mass spectrometry (ICP-MS) for quantitative analysis in environmental and life sciences: a review of challenges, solutions, and trends

This focal point review provides an overview of recent developments and capabilities of inductively coupled plasma mass spectrometry (ICP-MS) coupled with different separation techniques for applications in the fields of quantitative environmental and bio-analysis. Over the past years numerous technical improvements, which are highlighted in this review, have helped to promote the evolution of ICP-MS to one of the most versatile tools for elemental quantification. In particular, the benefits and possibilities of using state-of-the-art hyphenated ICP-MS approaches for quantitative analysis are demonstrated with a focus on environmental and bio-analytical applications.