An evaluation of the performance of a continuous flow hydride generator-nebulizer for flame atomic absorption spectrometry was carried out. Optimization of nebulizer gas flow rate, sample acid concentration, sample and tetrahydroborate uptake rates and reductant concentration, on the As and Se absorbance signals was carried out. A hydrogen-argon flame was used. An improvement of the analytical ...

Two flow methods, based, respectively, on flow-injection analysis (FIA) and on multicommutated flow analysis (MCFA), were compared with regard to their use for the determination of total selenium in infant formulas by hydride-generation atomic absorption spectrometry. The method based on multicommutation provided lower detection and quantification limits (0.08 and 0.27 μg L(-1) compared to 0.59...

The changes in the oxidation state of vanadium in artificial and natural seawater samples were studied by electrothermal atomic absorption spectrometry (ETAAS) with a direct injection of a resin suspension. V(IV) and V(V) were extracted as the complex with Chromazurol B and with N-cinnamoyl-N-2,3-xylylhydroxylamine, respectively, using a suspension of an anion-exchange resin and determined by E...

The concentration of Cadmium (Cd) and lead (Pb) in different cigarette brands sold and/or produced in Saudi Arabia were determined by atomic absorption spectrometry (AAS). Average levels of Cd and Pb in different cigarette brands in Saudi Arabia were 1.81 and 2.46 μg g1 (dry weight), respectively. The results obtained in this study estimate the average quantity of Cd inhaled from smoking one pa...

A simple and sensitive method is described for the determination of trace lead in Chinese herbs by derivative atom trapping flame atomic absorption spectrometry (D-AT-FAAS) with a modified water-cooled quartz atom-trapping tube. The effects that influence the sensitivity of the derivative method, such as the trap position, the flame conditions and the collection time, were studied. The characte...

Flow-injection manifolds are described which allow the preconcentration of lead for flame atomic absorption determinations, using columns contained within the sample loop of an injection valve. An interface was designed which allowed the valves and pump in the system to be controlled by an autosampler which enabled precise timing of preconcentration and elution steps. The effects of sample flow...

An etching technique for the determination of the metallic impurities distribution in silicon wafers has been developed. An area of 10 mmphi and 10 microm depth was etched by 100 microL of an etching solution with a HF and HNO3 mixture. The acid matrix was evaporated on the wafer surface by IR lamp illumination and vacuum exhaust. Metallic impurities remaining on the wafer surface were redissol...

Electrostatics is one of the fundamental driving forces of the interaction between biomolecules in solution. In particular, the recognition events between viruses and host cells are dominated by both specific and non-specific interactions and the electric charge of viral particles determines the electrostatic force component of the latter. Here we probe the charge of individual viruses in liqui...

Changes in nuclear K+ electrochemical activity and total nuclear K+ content in salivary glands of Chironomus tentans were measured with ion-selective microelectrodes based on valinomycin and with flameless atomic absorption spectrometry, respectively. The K+ activity increased by a factor of 2.6 and the total K+, by a factor of 1.5 as oligopausing larvae developed into prepupae. The extent of d...

The aim of this study was the occupational exposure assessment to lead and manganese of workers in an armament repair shop of a military organization. The air of the working environment was assessed in the environmental monitoring while the internal dose biological indicators for lead and manganese, in blood and urine, were used in biological monitoring. Metals concentration in filters and biol...