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dosaje de N-ACETILS-2-HIDRIXIETIL-LCISTEINA para oxido de etileno

1 agosto, 2004
Necesito alguna información sobre dosaje en orina de N-ACETILS-2-HIDRIXIETIL-LCISTEINA para expuestos a oxido de etileno.

Lamentablemente no disponemos de información para satisfacer su inquietud. Le envío copia de esta respuesta al Dr. Federico Contreras quien siempre colabora con nosotros en la parte analítica. Si el tiene información seguramente se la proporcionará.

POSTERIORMENTE

Le adjunto la respuesta del Dr Federico Contreras con la información solicitada por Udes.

"La N Acetil 2 Hidroxietil Cisteína se menciona efectivamente en la última edición del libro de Albiano como una sustancia en estudio para el monitoreo de exposición al óxido de etileno, aunque no se mencionan valores (sí existen máximos de óxido de etileno de 0.5 mg/m3 en aire espirado y 0.8 microgramos/dl en sangre durante la exposición). Les adjunto un abstract de JAT sobre el tema donde se menciona la metodología y trataré de averiguar si alguien lo está haciendo por acá, lo que por el instrumental parecería bastante improbable. ".

Publicado en el Journal of Analytical Toxicology, Volume 22, Number 2, March/April 1998, pp. 96-104.
A Rapid, Sensitive Method for the Quantitation of N-Acetyl-S-(2-Hydroxyethyl)-L-Cysteine in Human Urine Using Isotope-Dilution HPLC-MS-MS
D.B. Barr and D.L. Ashley
Because of increasing concern about exposure to carcinogens and other toxicants, reliable methods for biological monitoring of potentially exposed populations must be developed. For biological monitoring to be useful, appropriate biomarkers of exposures to xenobiotics must be identified, and sensitive, specific methods for quantifying the targeted biomarker must be developed. We have developed a sensitive and selective method for the analysis of N-acetyl-S-(2-hydroxyethyl)-L-cysteine (HEMA), a urinary metabolite of at least three different known human carcinogens (vinyl chloride, ethylene oxide, and ethylene dibromide). The method uses strong anion-exchange solid-phase extraction and isotope-dilution high-performance liquid chromatography-tandem mass spectrometry. Our method is simple and is not labor intensive; the preparation time per sample is less than 10 min. Because urine samples vary in both their concentration and ion strength, intersample variability in HEMA recovery during the extraction is large. To overcome this inherent limitation, we use the isotope-dilution technique, which allows a complete correction for the extraction recovery for each sample. The limit of detection of the method is 0.68 µg/L in a 1-mL urine sample with a coefficient of variation of 22% (determined by replicate analyses at both 4 and 11 µg/L) and an accuracy indistinguishable from 100%. Preliminary analyses of urine from a population with no known overt exposure to the parent toxicants show a frequency of detection of approximately 75%, which indicates that this method has the sensitivity to detect urinary HEMA derived from environmental exposure. We are currently using this method to establish a reference range of background exposure to these toxicants in the U.S. population.