RESUMEN
A helium discharge has been evaluated as an element-selective, gas chromatographic detector for volatile organohalogen compounds. Absolute limits of detection ranged from 3 pg for chloroform to 29 pg for p-dibromobenzene with a linear response of 10(3)-10(4). The relative response of the detector was determined to be based solely on the mass of the halogen species present. This feature allowed for relatively simple quantitation of chlorinated and brominated haloform species in water samples by the addition of a single internal standard for calibration of the halogen response.
Asunto(s)
Hidrocarburos Halogenados/análisis , Contaminantes Químicos del Agua/análisis , Contaminantes del Agua/análisis , Cromatografía de Gases/métodos , Helio , Análisis de Regresión , VolatilizaciónRESUMEN
Methods are presented for the determination of methylmercury in fish, water, urine, and sediments, and diorganomercury compounds in water. Two significant differences from previous methods are the use of methylene chloride extracting solvent which permits sample extracts to be concentrated to volumes as low as 0.1 mL, and use of a gas chromatograph interfaced to an atmospheric pressure active nitrogen (APAN) afterflow detector. Such a detector is very sensitive and selective for Hg at picogram levels. Thus, limits of detection were significantly enhanced.
