Fast and reliable analytical methods for mercury speciation would aid in understanding mercury offgas chemistry. Presently, the U.S. Environmental Protection Agency (EPA) regulates only total mercury; however, many studies indicate that mercury toxicity is highly dependent on the mercury speciation. For example, amalgams and mercury sulfides have relatively low toxicities, while organomercury a...

Investigations of coherent effects in resonant media, namely coherent population trapping (CPT) and electromagnetically induced transparency (EIT) [1,2], which can dramatically modify the absorptive and dispersive properties of an atomic vapor, have caused a rebirth of interest in the problem of light propagation through a dispersive medium. In the last decade, the study of the dispersive prope...

We present a theoretical framework for studying spatially dependent absorption in a thermal vapor of multilevel atoms, of arbitrary optical thickness. The atomic state dynamics, governed by a standard atom-optical master equation, are self-consistently coupled to the axial evolution of the probe beam intensity and the effusive gas dynamics. We derive steady-state equations for the spatially var...

In an effort to reduce the experimental bias involved in the analysis of gaseous elemental mercury (Hg(o)), the blank response from gold-coated adsorption tubes has been investigated using cold vapor atomic absorption spectrometry (CVAAS). Our study has been compared with our recent investigation on memory effect in a cold vapour atomic fluorescence spectrometry (CVAFS). The pattern of blank re...

A flow system was developed for the determination of total mercury concentration in fish samples by cold vapor atomic absorption spectrophotometry (CVAAS), based on the multicommuted flow injection analysis (MCFIA) approach. The system uses independently controlled solenoid valves for the introduction of reagents and samples. When not injected, solutions were recirculating to the reservoir bott...

A procedure using an automated microwave flow digestion technique was developed and validated for the digestion of samples of certifiable color additives before mercury determination by cold vapor atomic absorption spectrometry. Recovery studies were performed by spiking most of the color additives subject to batch certification by the U.S. Food and Drug Administration with inorganic mercury (H...