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Mineral Water (mineral + water)
Selected AbstractsDetermination of iodide in samples with complex matrices by hyphenation of capillary isotachophoresis and zone electrophoresisELECTROPHORESIS, Issue 20 2007Pavla Pant Abstract A method has been developed for the determination of iodide in mineral water, seawater, cooking salt, serum, and urine based on hyphenation of capillary ITP and zone electrophoresis. A commercially available instrumentation for capillary ITP with column-switching system was used. ITP served for removal of chloride present in the analyzed samples in a ratio of 106,107:1 to iodide, zone electrophoresis was used for evaluation. Isotachophoretic separation proceeded in a capillary made of fluorinated ethylene,propylene copolymer of 0.8,mm id and 90,mm total length to the bifurcation point filled with a leading electrolyte (LE) composed of 8,mM HCl,+,16,mM ,-alanine (,-Ala),+,10% PVP,+,2.86,mM N2H4×2HCl, pH,3.2; and a terminating electrolyte composed of 8,mM H3PO4,+,16,mM ,-Ala,+,10% PVP,+,5,mM N2H4, pH,3.85 for all the matrices except seawater. For ITP of seawater the LE consisted of 50,mM HCl,+,100,mM ,-Ala,+,10% PVP +,2.86,mM N2H4×2HCl, pH,3.52. Distance of conductivity detector from the injection point and bifurcation point was 52 and 38,mm, respectively. Zone electrophoresis was performed in a capillary made of fused silica of 0.3,mm id and 160,mm total length filled with LE from isotachophoretic step. LODs reached for all matrices were 2,3×10,8,M concentration (2.5,4,,g/L) enabled monitoring of iodide in all analyzed samples with RSD 0.4,9.3%. Estimated concentrations of iodide in individual matrices were 10,6,10,8,M. [source] A model predicting waterborne cadmium bioaccumulation in Gammarus pulex: The effects of dissolved organic ligands, calcium, and temperatureENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 11 2009Bastien Pellet Abstract Metal bioavailability depends on the presence of organic ligands in the water and on the concentrations of competitive cations. The present study aims at testing whether the diffusive gradient in thin films technique (DGT) could be used to take into account Cd speciation and its consequences on bioavailability in a bioaccumulation model and whether the influences of the Ca concentration and temperature also should be considered. Four kinetic experiments were conducted on Gammarus pulex: a calibration of Cd turnover rates and of the DGT lability in mineral water, a study of the influence of ethylenediaminetetraacetic acid (EDTA) and humic acids (HA) on uptake rates, and two experiments testing the influence of the Ca concentrations and temperature on Cd uptake clearance rates (ku). In mineral water, where Cd was considered fully labile, the ku was 0.46 L g,1 d,1, and the depuration rate was 0.032 d,1. The initial Cd influxes were lowered significantly by additions of 10 ,g L,1 of EDTA or 10 mg L,1 of HA in the water but not at 5 mg L,1 HA, even if DGT measurements proved that Cd formed Cd,HA complexes in that treatment. Increasing Ca concentrations lowered ku values, and a competitive inhibition model between Ca and Cd fitted the data. A 30% enhancement of ku values was observed when the temperature was increased by 8°C, which appeared comparatively as a weak effect. Thus, taking into account the metal speciation and the influence of the Ca concentration should improve Cd bioaccumulation modeling in amphipods. In freshwater, where metal bioavailability is reduced by the presence of dissolved organic matter, forecasting Cd waterborne uptake using the labile concentrations should allow robust comparisons between laboratory and field studies. [source] Diversity and abundance of Bacteria and Archaea in the Bor Khlueng Hot Spring in ThailandJOURNAL OF BASIC MICROBIOLOGY, Issue 6 2004Pattanop Kanokratana The prokaryotic diversity in the Bor Khlueng hot spring in Ratchaburi province, Thailand was investigated by a culture-independent molecular approach. This hydrothermal pool is located in the central part of Thailand and contains sulfide-rich mineral water that is believed to relieve muscle ache and pain. The water flow year-round with temperature ranging between 50,57 °C. Community DNA was extracted directly from sediment samples by coring to depth of ,20,30 cm. Small-subunit rRNA genes (16S rDNA) were amplified by PCR using primers specific for the domains Archaea and Bacteria. The PCR products were cloned and sequenced. For the bacterial rDNA clone library, 200 clones were randomly selected for further analyses. After restriction fragment length polymorphism (RFLP) analysis of rDNA clones and exclusion of chimeric sequences 36 phylotypes were obtained. The Bor Khlueng phylotypes spanned a wide range within the domain Bacteria, occupying eleven major lineages (phyla). Almost a quarter (23%) of the clones were classifed as Acidobacteria. The other clones were grouped into the Bacteriodetes (19%), Nitrospirae (13%), Proteobacteria (12%), Deinococcus-Thermus lineage (11%), planctomycetes (6%), and Verrucomicrobia (5%). The four remaining phyla, 5% each, were assigned to Actinobacteria, Chloroflexi, Cyanobacteria, and the candidate division "OP10". For the archaeal 16S rRNA gene sequence library, 25 distinct phylotypes were obtained, 17 clones were found to be associated with Crenarahaeota and 8 clones were associated with Euryarachaeota. The findings of the molecular survey of this so far not investigated site showed that Bor Khlueng hot spring is a potential rich source of unique bacterial and archaeal species. The great majority (,80%) of the prokaryotic sequences detected in Bor Khlueng were unknown. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Effect of Water Hardness on the Taste of Alkaline Electrolyzed WaterJOURNAL OF FOOD SCIENCE, Issue 4 2005Masamichi Koseki ABSTRACT: The effect of water hardness on the taste of alkaline electrolyzed water (AEW) was examined by sensory evaluation. Sensory test 1 of commercial bottled mineral water to which calcium and/or magnesium salts had been added was performed by panelists who evaluated the effect of hardness on the taste of water using a scoring method (hedonic scaling test) and a 1-pair comparison method. The water, in which the calcium concentration and the magnesium concentration was 20 mg/L and 2 mg/L, respectively, was found to taste better than any water containing other concentrations of calcium and magnesium. Sensory test 2 of bottled mineral waters having hardnesses of 30 mg/L to 290 mg/L, of activated carbon filtration water having a hardness of 50 mg/L, and of AEWs was performed by panelists using a scoring method (hedonic scaling test) and a pair test, and their preferences for the taste of AEWs was surveyed. The taste of AEW made by electrolyzing activated carbon filtration water did not differ from that of the water before it was electrolyzed. The same was true of AEW made by electrolyzing bottled mineral water having a hardness of 80 mg/L. However, 3 kinds of AEWs made by electrolyzing bottled mineral waters having hardnesses of 30 mg/L, 170 mg/L, and 290 mg/L were found to taste less pleasant than each bottled mineral water before being electrolyzed. The results of sensory tests 1 and 2 show that good-tasting AEW could be produced by an alkaline water electrolyzed from most tap water of Japan because its hardness varies from approximately 50 mg/L to 80 mg/L. [source] Human enamel erosion in constant composition citric acid solutions as a function of degree of saturation with respect to hydroxyapatiteJOURNAL OF ORAL REHABILITATION, Issue 1 2005M. E. BARBOUR summary, The objective of this study was to investigate human enamel erosion under constant composition conditions, as a function of solution degree of saturation (DS) with respect to hydroxyapatite. The experimental conditions were relevant to the initial stages of enamel erosion by soft drinks. Nanoindentation was used to compare enamel surface softening caused by a control mineral water and two citric acid solutions with DS = 0·000 and DS = 0·032, both having pH 3·30. Enamel hardness and reduced elastic modulus were measured after 0, 30, 60, 120, 300 and 600 s exposure. A statistically significant change in enamel hardness was detected after 30 s exposure to both citric acid solutions, indicating that nanoindentation is extremely sensitive to the initial stages of erosion. There was a statistically significant difference between the mechanical properties of enamel exposed to the two citric acid solutions after 30, 60 and 120 s. At these times, the solution with DS = 0·000 caused twice as much enamel softening as that with DS = 0·032. This demonstrates that it may be possible to design a soft drink with a low erosive potential and a good taste by a small change in DS, at a typical drink pH. [source] Chemical and isotopic signatures of Na/HCO3/CO2 -rich geofluids, North PortugalGEOFLUIDS (ELECTRONIC), Issue 4 2006J. M. MARQUES Abstract Geochemical and isotopic studies have been undertaken to assess the origin of CO2 -rich waters issuing in the northern part of Portugal. These solutions are hot (76°C) to cold (17°C) Na,HCO3 mineral waters. The ,2H and ,18O signatures of the mineral waters reflect the influence of altitude on meteoric recharge. The lack of an 18O-shift indicates there has been no high temperature water,rock interaction at depth, corroborating the results of several chemical geothermometers (reservoir temperature of about 120°C). The low 14C activity (up to 9.9 pmC) measured in some of the cold CO2 -rich mineral waters (total dissolved inorganic carbon) is incompatible with the presence of 3H (from 1.7 to 4.1 TU) in those waters, which indicates relatively short subsurface circulation times. The ,13C values of CO2 gas and dissolved inorganic carbon range between ,6, and ,1, versus Vienna-Peedee Belemnite, indicating that the total carbon in the recharge waters is being diluted by larger quantities of CO2 (14C-free) introduced from deep-seated (upper mantle) sources, masking the 14C-dating values. The differences in the 87Sr/86Sr ratios of the studied thermal and mineral waters seem to be caused by water,rock interaction with different granitic rocks. Chlorine isotope signatures (,0.4, < ,37Cl < +0.4, versus standard mean ocean chloride) indicate that Cl in these waters could be derived from mixing of a small amount of igneous Cl from leaching of granitic rocks. [source] EVALUATION OF SURVIVAL PATTERNS AND CELLULAR INJURY OF PSEUDOMONAS AERUGINOSA IN DIFFERENT BOTTLED WATERS STORED UNDER VARIOUS CONDITIONSJOURNAL OF FOOD SAFETY, Issue 3 2001PAULA TEIXEIRA ABSTRACT Pseudomonas aeruginosa cells were inoculated into different waters and sampled after different periods of starvation in order to evaluate the influences of storage under daylight or dark conditions, the presence or absence of the autochthonous flora, the chemical composition of the water and the storage temperature, on survival Survival was investigated by plate counts on selective and nonselective agar media. Light, low temperature (4C) and presence of the autochthonous flora negatively influenced the survival of P. aeruginosa during starvation in water. Higher survival rates were observed in waters with high mineral content. During starvation, cells developed sensitivity to the selective medium demonstrating that research is needed in the development of new media, or improvement in the existing ones, for the enumeration of P. aeruginosa in water. Current selective media/methodologies for detecting P. aeruginosa in mineral waters may seriously underestimate the levels of or presence of this organism which might represent, in some cases, a hazard to the public health. [source] Effect of Water Hardness on the Taste of Alkaline Electrolyzed WaterJOURNAL OF FOOD SCIENCE, Issue 4 2005Masamichi Koseki ABSTRACT: The effect of water hardness on the taste of alkaline electrolyzed water (AEW) was examined by sensory evaluation. Sensory test 1 of commercial bottled mineral water to which calcium and/or magnesium salts had been added was performed by panelists who evaluated the effect of hardness on the taste of water using a scoring method (hedonic scaling test) and a 1-pair comparison method. The water, in which the calcium concentration and the magnesium concentration was 20 mg/L and 2 mg/L, respectively, was found to taste better than any water containing other concentrations of calcium and magnesium. Sensory test 2 of bottled mineral waters having hardnesses of 30 mg/L to 290 mg/L, of activated carbon filtration water having a hardness of 50 mg/L, and of AEWs was performed by panelists using a scoring method (hedonic scaling test) and a pair test, and their preferences for the taste of AEWs was surveyed. The taste of AEW made by electrolyzing activated carbon filtration water did not differ from that of the water before it was electrolyzed. The same was true of AEW made by electrolyzing bottled mineral water having a hardness of 80 mg/L. However, 3 kinds of AEWs made by electrolyzing bottled mineral waters having hardnesses of 30 mg/L, 170 mg/L, and 290 mg/L were found to taste less pleasant than each bottled mineral water before being electrolyzed. The results of sensory tests 1 and 2 show that good-tasting AEW could be produced by an alkaline water electrolyzed from most tap water of Japan because its hardness varies from approximately 50 mg/L to 80 mg/L. [source] | |||||||||||||