ABSTRACT
El arsénico (As) es un contaminante natural que afecta una amplia zona de Argentina. El nivel de As en agua de consumo es utilizado para evaluar la fuente de exposición y en orina para evaluar exposición a este tóxico. El presente trabajo tuvo como objetivo la optimización y validación metodológica de una técnica para la cuantificación de As [As suma = As inorgánico (AsI) + especies metiladas: ácido monometilarsónico (MMA) y ácido dimetilarsónico (DMA)], producto del metabolismo del AsI, por inyección en flujo- generación de hidruros- espectrometría de absorción atómica (IF-GH-EAA), previa derivatización con L-cisteína. La recuperación de las especies estudiadas: AsI (AsIII y AsV), MMA y DMA fue cercana al 100% en todos los casos. Los límites de detección y cuantificación encontrados fueron para agua y orina: 2 y 3 µg/L; 5 y 8 µg/L respectivamente y el rango dinámico de trabajo establecido fue desde 5 a 75 µg/L, permitiendo cuantificar As en muestras de agua cercanos a los estándares internacionales vigentes para valores máximos de As en agua de consumo y en orina en niveles comparables con los establecidos en población laboralmente no expuesta. Esta propuesta metodológica es una alternativa para evaluar la exposición al As en muestras de agua y orina, sin necesidad de utilizar prolongados pre-tratamientos de muestra, de forma más rápida y económica.
Arsenic (As) is a natural contaminant that affects a large area of Argentina. Quantification of As in drinking water has been used to evaluate the source of exposure and As in urine to assess exposure to this toxic. This study aimed to optimize and validate a methodological technique for the quantification of As [As sum = inorganic As (AsI) + methylated species: monometilarsonic acid (MMA) and dimetilarsinic acid (DMA)], product of AsI metabolism by flow injection hydridegeneration-atomic absorption spectrometry (FI-GH-AAS), after derivatization with L-cysteine. The recovery of the studied species: AsI (AsIII and AsV), MMA and DMA was close to 100% in all cases. The limits of detection and quantitation were foundfor water and urine: 2 and 3 µg/L; 5 and 8 µg/L respectively and a linear working range from 5 to 75 µg/L, allowing quantify As in water close to international standards of maximum As values for drinking water and urine samples with levels comparables with those found in people non exposed ocupacionally . This methodology is a valid alternative for assessing exposure to As in water and urine samples without the need of prolonged pre-treatment sample, more quickly and inexpensively.
Subject(s)
Water Supply/analysis , Arsenic/urine , Water Pollutants, Chemical/analysis , Water Pollutants, Chemical/adverse effects , Water Pollutants, Chemical/urine , Environmental Exposure , Argentina , Arsenicals/analysis , Arsenicals/adverse effects , Environmental Monitoring , Arsenic Poisoning/etiology , Arsenic Poisoning/urine , Spectrophotometry, AtomicABSTRACT
In a study observing the effect of spirulina in the treatment of chronic arsenic poisoning quantitative estimation of arsenic in the urine of the patients was necessary. It was decided to try a modification of the arsine generator in the process. An alternative apparatus was designed following the structure of arsine generator by White (1976) using a 50-ml conical flask with rubber cork, 4-ml injection vial, two 3" long glass tubes and a glass test tube. An experiment was carried out with solutions containing known amounts of arsenic. The alternative arsine generator was tried in the estimation of arsenic content in those solutions. The results revealed that the apparatus permitted correct measurement of arsenic concentration. The alternative arsine generator was cheap easy to use and provided authentic results in estimation of arsenic concentration in the urine of patients with chronic arsenic poisoning.