a novel optical sensor has been proposed for sensitive determination of bismuth ion basedon immobilization of 4-(4-nitrophenylazo)-1-naphthol on a triacetylcellulose membrane.chemical binding of bismuth ions in solution with a 4-(4-nitrophenylazo)-1-naphtholimmobilized on the triacetylcelluse surface could be monitored spectrophotometrically. theoptode shows excellent response over wide concent...

The capacity of natural zeolites to absorb anionic pollutants from water is limited. This limitation can be overcome by modifying the surface of the minerals with organic cations. In this research, natural zeolite, Analcime was used for removing the nitrate and nitrite impurities from aqueous solutions. The surface of the zeolite was modified by tetramethylammonium and tetraethylammonium ions t...

Selenium is an essential element for humans, animals and some species of microorganisms. The biological function of selenium shows dual characteristics. The selenium content range between toxic and deficient concentration is very narrow. The present paper discusses the geographical distribution of two forms (total and water-soluble) of selenium in topsoil (plough layer for cultivated soils, elu...

Introduction Natural and artificial radionuclides are the main sources of human radiation exposure. These radionuclides, which are present in the environment, can be dissolved into water. Evidence suggests that radionuclides being entered the human body through drinking or hot spring water can be harmful for human health. Materials and Methods In this study,10 samples were collected from ground...

the aim of this study was to evaluate and compare the sensitivity of plant bioassays:tradescantia-micronucleus (trad-mcn) tests using bnl 02 and 4430 clones, and crepis capillaris hairyroots chromosome aberrations test. the evaluation of the sensitivity of the tests was based on the example of the analysis of the genotoxicity of water samples from two natural water reservoirs in poland: the raw...

in this study, the possibility of microwave finish drying for two types of dried grapes (natural and sultana) was investigated. the samples were washed in water bath at given temperature ranges (25 and 45 c) for 30 to 60 minutes. after dewatering the samples, they were dried using microwave (at two powers: 270 and 450 w) and hot air convective dryer (at 50 c). water gain (%), effective moistu...

background: gavkhooni marsh is one of the most important marshes in iran. in the recent years, natural conditions of this marsh have been affected by agricultural and industrial activities in zayandehrood river catchment areas. this research was carried out in 2006 to assess some chemical parameters and the heavy metals concentration in water, soil, and plants in the area and to compare the res...

The aim of this work was to determine the natural fluoride concentrations in public water supplies in Piauí State, Brazil, in order to identify cities in risk for high prevalence of dental fluorosis. For each city, two samples of drinking water were collected in the urban area: one from the main public water supply and another from a public or residential tap from the same source. Fluoride anal...

a flow injection system is reported for the determination of fluoride based on its effects on the fluorescence intensity of al-morin complex at ph 3.0 in ethanol-warn mixture. the effect of important parameters such as excitation and emission wavelengths, ph, reagents concenkations, flow rate of the carrier stream, sample injection volume, time of measurepent and interferences are reported. cat...

We present here an improved and reliable method for measuring the concentration of dissolved inorganic carbon (DIC) and its isotope composition (delta(13)C(DIC)) in natural water samples. Our apparatus, a gas chromatograph coupled to an isotope ratio mass spectrometer (GCIRMS), runs in a quasi-automated mode and is able to analyze about 50 water samples per day. The whole procedure (sample prep...