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...

We use a layer-by layer electrostatic self-assembly technique to obtain in-plane oriented aggregates of mesogenic dye molecules cast from lyotropic chromonic liquid crystals (LCLCs) on mica substrates. The aqueous solutions of dye used for deposition are in the nematic phase. Atomic force microscopy and X-ray photoelectron spectroscopy of the dried film reveal that the LCLC molecules adsorb at ...

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...

Inorganic lead compounds are used most widely in paint and pigment industries. Because of exposure to lead dust in workers in a copying center, we compared blood lead levels in these workers to normal individuals and investigated the relationship between job tenures of the workers and their blood lead levels. This survey was performed on 20 simple workers in a copying center of Tehran Univ...

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...

more than 30 mineral elements have been found with different key functions in helping plants and animals to survive and live healthy. as a direct result, they have always attracted the attention of scientists. the quest is to find some efficient analytical and quantitative procedures in this study to determine some mineral and trace elements of iranian crocus sativus l. corms. several studies h...

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...

An alternative, low cost method for analyzing mercury in soil, sediment and gold mining residues was developed, optimized and applied to 30 real samples. It is semiquantitative, performed using an acid extraction pretreatment step, followed by mercury reduction and collection in a detecting paper containing cuprous iodide. A complex is formed with characteristic color whose intensity is proport...