Distribution Study of U,V, Mo,and Zr in Different Sites of Lakes Van and Hazar,River and Seawater Samples by ICP‐MS

The aim of this study is to investigate the concentrations of U, Th, V, Mo, and Zr in natural waters taken from Turkey. Among these water species, Lake Van is the largest soda lake and the fourth largest closed basin on Earth. The water samples were collected from 51 locations between 2008 and 2009. The inductively coupled plasma‐MS was used for determinations. The obtained U and Zr concentrations are in the range of 37–110 µg L^?1 and 17–78 µg L^?1 in Lake Van and 0.53–0.81 µg L^?1 and 0.15–0.19 µg L^?1 in Lake Hazar, respectively. The concentration of uranium in other studied waters varies from the lowest 0.09 µg L^?1 in Tigris (Dicle) river to the highest 4.0 µg L^?1 in Mediterranean Sea water. Mean Mo and V concentrations in the studied water samples were found to be in ranges of 0.1–17 and 2.7–113 µg L^?1, respectively. The obtained highest U concentration in Lake Van correlates with the highest Mo and Zr levels compared to the Lake Hazar and river waters. These results imply that there is a young occurrence of uranium minerals around Lake Van. It is concluded that there is about 50.000 ton of uranium in Lake Van water.     

Quantification of Diclofenac in Hospital Effluent and Identification of Metabolites and Degradation Products

In this study the occurrence of diclofenac and sub‐products in effluent emerging from the University Hospital at the Federal University of Santa Maria was investigated. One metabolite was identified and, in aqueous solution, three degradation products. The quantification was conducted by means of HPLC‐DAD, and the determination of metabolite and degradation products by LC–ESI–MS/MS–QTrap. For the HPLC‐DAD method, a 70:30 mixture of methanol/sodium phosphate was used in isocratic mode. For the LC–ESI–MS/MS–QTrap determinations, a mobile phase, where phase A was an ammonium acetate solution 5 × 10^?3 mol L^?1, and phase B was methanol (5 × 10^?3 mol L^?1)/ammonium acetate (9:1, v/v), on gradient mode. The LDs for the HPLC and LC–MS/MS methods, respectively, were 2.5 and 0.02 µg L^?1, the LQs, 8.3 and 0.05 µg L^?1, and the linear range from 10 up to 2000 µg L^?1 and 0.05 up to 10 µg L^?1. As expected, the LC–ESI–MS/MS–QTrap method was more sensitive and less laborious. The metabolite 4′‐hydroxy‐diclofenac was identified. Photolysis was used for the degradation studies and three products of diclofenac were identified (m/z of 214, 286 and 303) in aqueous solution. These results notwithstanding, no degradation products of diclofenac were found in the hospital effluent.     

Wetland nitrogen dynamics in an Adirondack forested watershed

Wetlands often form the transition zone between upland soils and watershed streams, however, stream–wetland interactions and hydrobiogeochemical processes are poorly understood. We measured changes in stream nitrogen (N) through one riparian wetland and one beaver meadow in the Archer Creek watershed in the Adirondack Mountains of New York State, USA from 1 March to 31 July 1996. In the riparian wetland we also measured changes in groundwater N. Groundwater N changed significantly from tension lysimeters at the edge of the peatland to piezometer nests within the peatland. Mean N concentrations at the peatland perimeter were 1·5, 0·5 and 18·6 µmol L^?1 for NH₄⁺, NO₃^? and DON (dissolved organic nitrogen), respectively, whereas peatland groundwater N concentration was 56·9, 1·5 and 31·6 µmol L^?1 for NH₄⁺, NO₃^? and DON, respectively. The mean concentrations of stream water N species at the inlet to the wetlands were 1·5, 10·1 and 16·9 µmol L^?1 for NH₄⁺, NO₃^? and DON, respectively and 1·6, 28·1 and 8·4 µmol L^?1 at the wetland outlet. Although groundwater total dissolved N (TDN) concentrations changed more than stream water TDN through the wetlands, hydrological cross‐sections for the peatland showed that wetland groundwater contributed minimally to stream flow during the study period. Therefore, surface water N chemistry was affected more by in‐stream N transformations than by groundwater N transformations because the in‐stream changes, although small, affected a much greater volume of water. Stream water N input–output budgets indicated that the riparian peatland retained 0·16 mol N ha^?1 day^?1 of total dissolved N and the beaver meadow retained 0·26 mol N ha^?1 day^?1 during the study period. Nitrate dominated surface water TDN flux from the wetlands during the spring whereas DON dominated during the summer. This study demonstrates that although groundwater N changed significantly in the riparian peatland, those changes were not reflected in the stream. Consequently, although in‐stream changes of N concentrations were less marked than those in groundwater, they had a greater effect on stream water chemistry—because wetland groundwater contributed minimally to stream flow. Copyright © 2004 John Wiley & Sons, Ltd.     

Development of Dispersive Liquid–Liquid Microextraction Based on Solidification of Floating Organic Drop for the Determination of Trace Lead in Water

A new method for determining lead (Pb) content was developed by dispersive liquid–liquid microextraction based on the solidification of floating organic droplets followed by flame atomic absorption spectrometry. Under optimum conditions, the calibration graph was linear within the Pb content range of 8.43–400 µg L^?1 with a detection limit of 2.53 µg L^?1. The relative standard deviation for 10 replicate measurements of 20 and 400 µg L^?1 of Pb were 3.41 and 2.78%, respectively. The proposed method was assessed through the analysis of certified reference water and recovery experiments.     

Determination of Trace Levels of Nickel and Manganese in Soil,Vegetable, and Water

A simple and reliable method for rapid and selective extraction and determination of trace levels of Ni²⁺ and Mn²⁺ was developed by ionic liquid (IL) based dispersive liquid–liquid microextraction coupled to flame atomic absorption spectrometry (FAAS) detection. The proposed method was successfully applied to the preconcentration and determination of nickel and manganese in soil, vegetable, and water samples. After preconcentration, the settled IL‐phase was dissolved in 100 µL of ethanol and aspirated into the FAAS using a home‐made microsample introduction system. Injection of 50 µL of each analyte into an air–acetylene flame provided very sensitive spike‐like and reproducible signals. Effective parameters such as pH, amount of IL, volume of the disperser solvent, concentration of the chelating agent, and effect of salt concentration were inspected by a (2^5‐1) fractional factorial design to identify the most important parameters and their interactions. Under optimum conditions, preconcentration of 10 mL sample solution permitted the detection of 0.93 µg L^?1 Ni²⁺ and 0.52 µg L^?1 Mn²⁺ with enrichment factors 77.2 and 82.6 for Ni²⁺ and Mn²⁺, respectively. The accuracy of the procedure was evaluated by analysis of a certified reference material (CRM TMDW‐500, drinking water).     

Determination of Sulfamethoxazole and Trimethoprim and Their Metabolites in Hospital Effluent

In this work, an analytical methodological study was carried out to determine the antimicrobials sulfamethoxazole and trimethoprim, as well as their metabolites, in hospital effluent. The determinations were conducted by liquid chromatography tandem mass spectrometry using a hybrid triple quadrupole‐linear ion trap mass spectrometer (LC‐QqLIT‐MS). The data acquisition was made in selected reaction monitoring (SRM) mode, in which two SRM transitions were monitored to ensure that the target compounds were accurately identified by the information dependent acquisition (IDA) function. The limits of detection (LOD) and quantification (LOQ) were 0.25 and 0.80 µg L^?1 for sulfamethoxazole and 0.15 and 0.50 µg L^?1 for trimethoprim. The linear range for the SMX was 0.8–100.0 µg L^?1 and TMP was 0.5–100.0 µg L^?1 on the basis of six‐point calibration curves generated by means of linear regression analysis. The coefficients of the correlation were higher than 0.999, which ensured the linearity of the method. The average concentration of sulfamethoxazole and trimethoprim found in hospital effluent was 27.8 and 6.65 µg L^?1, respectively. The analytical methodology employed allowed two metabolites to be identified, N4‐acetyl‐sulfamethoxazole and α‐hydroxy‐trimethoprim. Fragmentation pathways were proposed.     

Surfactant Enhance DLLME/FO‐LADS: Assay of Malachite Green Level in Aquatic Environment of Trout Fish

Malachite green (MG), a traditional agent used in aquaculture although is not approved; its low cost and high efficacy make illicit use likely. We developed a small‐scale, simple, and sensitive dispersive liquid–liquid microextraction procedure for the assay of trace amounts of MG in aquatic environment of Trout fish. Fiber optic‐linear array detection spectrophotometry with charge‐coupled device detector benefiting from a microcell was used for this purpose. The method is based on enhancement effect of an anionic surfactant on the extraction of MG in to very fine multidroplets of microextraction solvent which made assisted by disperser solvent. Under the optimum conditions, the enrichment factor 77.5 was obtained from a 5‐mL water sample. The calibration graph was linear up to 5 × 10^?7 mol L^?1 with detection limit of 1 × 10^?8 mol L^?1. The relative standard deviation for seven replicate measurements of 4 × 10^?7 and 5 × 10^?8 mol L^?1 of MG were 3.3 and 4.5%, respectively.     

Impact of Ca2+ and Mg2+ on the Removal of F− by Magnesium Potassium Phosphate

This study investigates the influence of Ca²⁺ and Mg²⁺ on the removal of F^? by magnesium potassium phosphate (MPP) from water. The kinetic experiments reveal that the F^? concentration decreased from 3.5 to 3.31 mg L^?1 in a single (F^?) system and to 1.45 mg L^?1 in a ternary system (F^?, Ca²⁺, and Mg²⁺) after 1 min, respectively. Thus, the F^? removal efficiencies are found to increase by about 53% with the co‐active effect of Ca²⁺ and Mg²⁺ in the solution. Moreover, Ca²⁺ and Mg²⁺ are almost completely removed in the F^?, Ca²⁺, and Mg²⁺ system. According to the pseudo‐first‐order modeling, the rate constants k for F^?, Ca²⁺, and Mg²⁺ are 0.00348, 0.0106, and 0.0159 min^?1 respectively; thus, Mg²⁺ > Ca²⁺ > F^?. In the ternary system, the removal efficiencies are 53.29–66.03% for F^?, 99.99–100% for Ca²⁺, and 87.21–95.19% for Mg²⁺ with initial pH 5–10. The removal efficiencies of F^? increases with increases in initial concentrations of F^?, Ca²⁺, and Mg²⁺. The removal of F^? is governed by two routes: 1) adsorption by electrostatic interactions and outer sphere surface complexation; 2) co‐precipitation with Ca₃(PO₄)₂, CaHPO₄, Mg₃(PO₄)₂, and Mg(OH)₂.     

Evaluating sulfur dynamics during storm events for three watersheds in the northeastern USA: a combined hydrological,chemical and isotopic approach

Concerns related to climate change have resulted in an increasing interest in the importance of hydrological events such as droughts in affecting biogeochemical responses of watersheds. The effects of an unusually dry summer in 2002 had a marked impact on the biogeochemistry of three watersheds in the north‐eastern USA. Chemical, isotopic and hydrological responses with particular emphasis on S dynamics were evaluated for Archer Creek (New York), Sleepers River (Vermont) and Cone Pond (New Hampshire) watersheds. From 1 August to 14 September 2002, all three watersheds had very low precipitation (48 to 69 mm) resulting in either very low or no discharge (mean 0·015, 0·15 and 0·000 mm day^?1 for Archer Creek, Sleepers River and Cone Pond, respectively). From 15 September to 31 October 2002, there was a substantial increase in precipitation totals (212, 246 and 198 mm, respectively) with increased discharge. Archer Creek was characterized by a large range of SO₄^2? concentrations (152 to 389 µeq L^?1, mean = 273 µeq L^?1) and also exhibited the greatest range in δ³⁴S values of SO₄^2? (?1·4 to 8·8 ‰ ). Sleepers River's SO₄^2? concentrations ranged from 136 to 243 µeq L^?1 (mean = 167 µeq L^?1) and δ³⁴S values of SO₄^2? ranged from 4·0 to 9·0 ‰ . Cone Pond's SO₄^2? concentrations (126–187 µeq L^?1, mean = 154 µeq L^?1) and δ³⁴S values (2·4 to 4·3 ‰ ) had the smallest ranges of the three watersheds. The range and mean of δ¹⁸O‐SO₄^2? values for Archer Creek and Cone Pond were similar (3·0 to 8·9 ‰ , mean = 4·5 ‰ ; 3·9 to 6·3 ‰ , mean = 4·9 ‰ ; respectively) while δ¹⁸O‐SO₄^2? values for Sleepers River covered a larger range with a lower mean (1·2 to 10·0 ‰ , mean = 2·5). The difference in Sleepers River chemical and isotopic responses was attributed to weathering reactions contributing SO₄^2?. For Archer Creek wetland areas containing previously reduced S compounds that were reoxidized to SO₄^2? probably provided a substantial source of S. Cone Pond had limited internal S sources and less chemical or isotopic response to storms. Differences among the three watersheds in S biogeochemical responses during these storm events were attributed to differences in S mineral weathering contributions, hydrological pathways and landscape features. Further evaluations of differences and similarities in biogeochemical and hydrological responses among watersheds are needed to predict the impacts of climate change. Copyright © 2008 John Wiley & Sons, Ltd.     

Occurrence of phthalate esters in the Seine River estuary (France)

The rigin and fate of six phthalate esters (dimethyl phthalate (DMP), diethyl phthalate (DEP), di‐n‐butyl phthalate (DnBP), butyl benzyl phthalate (BBP), di (2‐ethylhexyl) phthalate (DEHP) and di‐n‐octyl phthalate (DnOP)), were investigated during 2005 and 2006 in the densely populated Seine river estuary. Four compounds, DMP, DEP, DnBP and DEHP were detected at all the stations with DEHP (160–314 ng L^?1), followed by DEP (71–181 ng L^?1) and next DnBP (67–319 ng L^?1), except at la Bouille, where DnBP was the second most important compound. BBP and DnOP concentrations remained low and were not found at all the stations. Considering all six phthalates, Caudebec‐en‐Caux (beginning of the salinity gradient) was the least polluted station (464 ng L^?1), whereas Honfleur (771 ng L^?1) and La Bouille (716 ng L^?1) displayed the highest contamination levels, probably related to important industrial plants. From Caudebec‐en‐Caux to Honfleur (maximum turbidity), variation of DEHP concentration was related to that of suspended matter. In addition, the salinity rise in that area might have facilitated DEHP sorption upon particles. A significant correlation between flow magnitude and DEHP concentration was found (P < 0·01, n = 12), supporting the influence of the hydrological cycle upon contamination. Runoff contribution (56·9 kg d^?1) to river contamination was confirmed by the annual evolution of phthalate concentrations in the Seine river at Poses. Concentrations of DEHP in the tributaries were in the same range as those of the Seine River (100–350 ng L^?1), except for two in densely populated and industrialized areas: Robec (800 ng L^?1) and Cailly (970 ng L^?1). The treatment plant discharge fluxes were in the same range as those of tributaries (30·4–250 g d^?1). During high flow periods, the influence of tributaries and of treatment plants seemed to play a minor part in the contamination level of the Seine river estuary. Copyright © 2009 John Wiley & Sons, Ltd.     

Nitrate content and potential microbial signature of rock glacier outflow,Colorado Front Range

Here we characterize the nutrient content in the outflow of the Green Lake 5 rock glacier, located in the Green Lakes Valley of the Colorado Front Range. Dissolved organic carbon (DOC) was present in all samples with a mean concentration of 0·85 mg L^?1 . A one‐way analysis of variance test shows no statistical difference in DOC amounts among surface waters (p = 0·42). Average nitrate concentrations were 69 µmoles L^?1 in the outflow of the rock glacier, compared to 7 µmoles L^?1 in snow and 25 µmoles L^?1 in rain. Nitrate concentrations from the rock glacier generally increased with time, with maximum concentrations of 135 µmoles L^?1 in October, among the highest nitrate concentrations reported for high‐elevation surface waters. These high nitrate concentrations appear to be characteristic of rock glacier outflow in the Rocky Mountains, as a paired‐difference t‐test shows that nitrate concentrations from the outflow of 7 additional rock glaciers were significantly greater compared to their reference streams (p = 0·003). End‐member mixing analysis suggest that snow was the dominant source of nitrate in June, ‘soil’ solution was the dominant nitrate source in July, and base flow was the dominant source in September. Fluoresence index values and PARAFAC analyses of dissolved organic matter (DOM) are also consistent with a switch from terrestrial DOM in the summer time period to an increasing aquatic‐like microbial source during the autumn months. Copyright © 2006 John Wiley & Sons, Ltd.     

On‐line Solid Phase Extraction of Copper in Water Samples with Flow Injection Flame Atomic Absorption Spectrometry

An on‐line solid phase extraction method for the preconcentration and determination of Cu(II) by flame atomic absorption spectrometry has been described. The procedure is based on the retention of Cu(II) ions at pH 6.0 on a minicolumn packed with Amberlite XAD‐1180 resin impregnated with chrome azurol S. After preconcentration, Cu(II) ions adsorbed on the impregnated resin were eluted by 1 mol L^?1 HNO₃ solution. Several parameters, such as pH, type of eluent, flow rates of sample and eluent solutions, amount of resin were evaluated. At optimized conditions, for 3.5 min of preconcentration time, the system achieved a detection limit of 1.0 µg L^?1, and a relative standard deviation of 1.2% at 0.2 µg mL^?1 copper. An enrichment factor of 56‐fold was obtained with respect to the copper determination. The proposed method was successfully validated by the analysis of standard reference material (TMDA 54.4 lake water) and recovery studies. The method was applied to the preconcentration of Cu(II) in natural water samples.     

Aerosol deposition velocities on the Pacific and Atlantic oceans calculated from7Be measurements

The concentrations of⁷Be have been measured in Pacific and Atlantic ocean water for the past several years to determine the deposition velocity of aerosol particles on the ocean surface.⁷Be is produced at a relatively constant rate in the atmosphere by spallation reactions of cosmic rays with atmospheric nitrogen and oxygen. Immediately after its formation⁷Be becomes attached to aerosol particles, and therefore can serve as tracers of the subsequent behavior of these particles. Isopleths of⁷Be surface water concentrations,⁷Be inventory in the ocean, and deposition velocity have been prepared for the Pacific Ocean from 30°S to 60°N and for the Atlantic Ocean from 10°N to 55°N. The concentrations, inventories and deposition velocities tended to be higher in regions where precipitation was high, and generally increased with latitude. The average flux of⁷Be across the ocean surface was calculated to be 0.027 atoms cm^?2 s^?1 which is probably not significantly greater than the worldwide average⁷Be flux across land and ocean surfaces of 0.022 atoms cm^?2 s^?1 calculated by Lal and Peters. The average deposition velocity was calculated to be 0.80 cm s^?1. This value may be 10–50% too low, since it was calculated using atmospheric⁷Be concentrations which were measured at continental stations. Measurements of atmospheric⁷Be concentrations at ocean stations suggest that the concentrations at the continental stations averaged 10–50% higher than the concentrations over the ocean.     

The effect of drawdown on suspended solids and phosphorus export from Columbia Lake,Waterloo, Canada

This study examines the effect of drawdown on the timing and magnitude of suspended solids and associated phosphorus export from a 12 ha reservoir located in an urbanized watershed in southern Ontario, Canada. Water level in Columbia Lake was lowered by 1·15 m over a 2‐week period in November 2001. The total phosphorus (TP) concentrations ranged from 63 to 486 µg L^?1 in Columbia Lake and 71 to 373 µg L^?1 at its outflow. All samples exceeded the Provincial Water Quality Objective of 30 µg TP L^?1. Outflow concentrations of suspended solids and TP increased significantly with decreasing lake level and were attributed to the resuspension of cohesive bottom sediments that occurred at a critical threshold lake level (0·65 m below summer level). Suspended solids at the outflow consisted of flocculated cohesive materials with a median diameter (D₅₀) of c. 5 µm. Particulate organic carbon accounted for 8·5% of the suspended solids export by mass. A total mass of 18·5 t of suspended solids and 62·6 kg TP was exported from Columbia Lake, which represents a significant pulse of sediment‐associated P to downstream environments each autumn during drawdown. The downstream impacts of this release can be minimized if the water level in Columbia Lake is lowered no more than 0·5 m below summer levels. Copyright © 2004 John Wiley & Sons, Ltd.     

Selective Separation/Preconcentration of Silver Ion in Water by Multiwalled Carbon Nanotubes Microcolumn as a Sorbent

The present paper proposes the application of multiwalled carbon nanotubes (MWCNTs) as a solid adsorbent for selective separation/preconcentration of silver(I) in water samples prior to flame atomic absorption spectrometry. The procedure is based on the solid phase extraction of Ag(I)–2‐mercaptobenzothiazole chelate on MWCNTs. The elution step is carried out with 5 mL of 2 mol L^?1 HNO₃ in acetone solution at a flow rate of 1.0 mL min^?1. The influences of the various analytical parameters including pH of the solution, eluent type, sample volume, flow rates of eluent, matrix ions were investigated for optimization of the presented procedure. Tests of addition/recovery for analyte ion in real samples were performed with satisfactory results. Preconcentration factor and limit of detection for Ag(I) were 160 and 0.21 µg L^?1, respectively. The synthesized MWCNT exhibited excellent stability in eluent solution and its adsorption capacity was 5.4 mg of silver per gram of sorbent. The proposed method was successfully applied to trace silver determination in a variety of environmental water samples.     

Beryllium‐7 wet deposition variation with storm height,synoptic classification,and tree canopy state in the mid‐Atlantic USA

Short‐lived fallout isotopes, such as beryllium‐7 (⁷Be), are increasingly used as erosion and sediment tracers in watersheds. ⁷Be is produced in the atmosphere and delivered to the Earth's surface primarily in precipitation. However, relatively little has been published about the variation in ⁷Be wet deposition caused by storm type and vegetation cover. Our analysis of precipitation, throughfall, and sediments in two forested, headwater catchments in the mid‐Atlantic USA indicates significant variation in isotope deposition with storm type and storm height. Individual summer convective thunderstorms were associated with ⁷Be activity concentrations up to 5.0 Bq l^?1 in precipitation and 4.7 Bq l^?1 in throughfall, while single‐event wet depositional fluxes reached 168 Bq m^?2 in precipitation and 103 Bq m^?2 in throughfall. Storms originating from the continental USA were associated with lower ⁷Be activity concentrations and single‐event wet depositional fluxes for precipitation (0.7–1.2 Bq l^?1 and 15.8–65.0 Bq m^?2) and throughfall (0.1–0.3 Bq l^?1 and 13.5–98.9 Bq m^?2). Tropical systems had relatively low activity concentrations, 0.2–0.5 Bq l^?1 in precipitation and 0.2–1.0 Bq l^?1 in throughfall, but relatively high single‐event depositional fluxes due to large rainfall volumes, 32.8–67.6 Bq m^?2 in precipitation and 25.7–134 Bq m^?2 in throughfall. The largest sources of ⁷Be depositional variation were attributed to storm characteristics including precipitation amount and maximum storm height. ⁷Be activity associated with fluvial suspended sediments also exhibited the highest concentration and variability in summer (175–1450 Bq kg^?1). We conclude the dominant source of variation on event‐level ⁷Be deposition is storm type. Our results illustrate the complex relationships between ⁷Be deposition in precipitation and throughfall and demonstrate event‐scale relationships between the ⁷Be in precipitation and on suspended sediment. Copyright © 2015 John Wiley & Sons, Ltd.     

Correlating specific conductivity with total hardness in gypsum karst waters

Modern digital conductivity meters are readily portable, robust, cheap, and give precisely reproducible values of specific electrical conductivity (SpC, in µS cm^?1). Here we investigate the accuracy of their estimates of the amounts of gypsum dissolved in waters collected in gypsum karst terrains, expressed as total hardness (TH) in mg L^?1 of CaSO₄·2H₂O (GYP). Total dissolved solid concentrations (TDS) are also considered. Curves obtained with the program PHREEQC, for the dissolution of pure gypsum in water at 25 C, are compared with 574 comprehensive water chemical analyses selected from gypsum karst studies in Europe and the Americas. Principal common and foreign ions encountered are the BNC group (bicarbonates, nitrates, chlorides). It is found that GYP = 1·12^·SpC + 62 where BNC < 33% (Cl^? < 5%), with one standard error <5% for waters with SpC > 2400 µS cm^?1; GYP = 0·74^·SpC + 777 where BNC < 33% (5% ≤ Cl^? < 15%), with one standard error <10% for waters with SpC > 3100 µS cm^?1; GYP = 0·97^·SpC ? 209 where BNC < 33% and Cl^? ≥ 15%, with one standard error <10% for samples with SpC > 4300 µS cm^?1. There are similar results for the more complex waters found in gypsum karsts where much carbonate rock or salt is also present, to the limit of BNC < 50% for what may reasonably be defined as ‘gypsum waters’. Values of R² for linear correlations of different subsets of the water samples range from 0·69 to 0·96, the majority being >0·8. Copyright © 2006 John Wiley & Sons, Ltd.     

Removal of Heavy Metals from Synthetic Mixture as well as Pharmaceutical Sample Via Cation Exchange Resin Modified with Rhodamine B: Its Thermodynamic and Kinetic Studies

A new sorbent was prepared by loading rhodamine B on Amberlite IR‐120. Various physico‐chemical parameters such as effects of adsorbate concentration, contact time, pH, and temperature on the sorption of the dye have been studied. Thermodynamic parameters (ΔH° and ΔS°) were also evaluated for the sorption of dye. Kinetic studies revealed that the sorption of the dye was best fit for pseudo‐second‐order kinetic. The metal ion uptake in different solvent systems has been explored through column studies. On the basis of distribution coefficient (K_d), some heavy metal ions of analytical interest from binary mixtures have been separated. The limit of detection (LOD) for the Ni²⁺ and Fe³⁺ metal ions was 0.81 and 0.60 µg L^?1, and the limit of quantification (LOQ) was found to be 2.72 and 2.0 µg L^?1. This sorbent has also been successfully applied in the analysis of multivitamin formulation. The applicability of the modified resin in the separation of heavy metals constituting real and synthetic samples has been explored.     

Toxicological Effects Induced by Cadmium in Gills of Manila Clam Ruditapes philippinarum Using NMR‐Based Metabolomics

Cadmium (Cd) has become an important heavy metal contaminant in the sediment and seawater along the Bohai Sea and been of great ecological risk due to its toxic effects to marine organisms. In this work, the toxicological effects caused by environmentally relevant concentrations (10 and 40 µg L^?1) of Cd were studied in the gill tissues of Manila clam Ruditapes philippinarum after exposure for 24, 48, and 96 h. Both low (10 µg L^?1) and high (40 µg L^?1) doses of Cd caused the disturbances in energy metabolism and osmotic regulation and neurotoxicity based on the metabolic biomarkers such as succinate, alanine, branched chain amino acids, betaine, hypotaurine, and glutamate in clam gills after 24 h of exposure. However, the recovery of toxicological effects of Cd after exposure for 96 h was obviously observed in clam to Cd exposures. Overall, these results indicated that NMR‐based metabolomics was applicable to elucidate the toxicological effects of heavy metal contaminants in the marine bioindicator.     

Toward the feldspar alternative for cosmogenic 10Be applications

The possibility of quantifying surface processes in mafic or volcanic environment using the potentialities offered by the in situ-produced cosmogenic nuclides, and more specifically by the in situ-produced ¹⁰Be, is often hampered by the rarity of quartz minerals in the available lithologies. As an alternative to overcome this difficulty, we explore in this work the possibility of relying on feldspar minerals rather that on quartz to perform in situ-produced ¹⁰Be measurements in such environments. Our strategy was to cross-calibrate the total production rate of ¹⁰Be in feldspar (P_10fsp) against the total production rate of ³He in pyroxene (P_3px) by measuring ³He and ¹⁰Be in cogenetic pyroxene (³He_px) and feldspar (¹⁰Be_fsp). The samples were collected from eight ignimbritic boulders, exposed from ca 120 to 600 ka at elevations ranging from 800 to 2500 m, along the preserved rock-avalanche deposits of the giant Caquilluco landslide (18°S, 70°W), Southern Peru. Along with data recently published by Blard et al. (2013a) at a close latitude (22°S) but higher elevation (ca. 4000 m), the samples yield a remarkably tight cluster of ³He_px - ¹⁰Be_fsp total production ratios whose weighted-mean is 35.6 ± 0.5 (1σ). The obtained weighted-mean ³He_px - ¹⁰Be_fsp total production ratio combined with the local ³He_py total production rate in the high tropical Andes published by Martin et al. (2017) allows to establish a total SLHL ¹⁰Be in situ-production rate in feldspar mineral (P_10fsp) of 3.57 ± 0.21 at.g⁻¹.yr⁻¹ (scaled for the LSD scaling scheme, the ERA40 atm model and the VDM of Lifton, 2016).Despite the large elevation range covered by the whole dataset (800–4300 m), no significant variation of the ³He_px - ¹⁰Be_fsp total production ratios in pyroxene and feldspar was evidenced. As an attempt to investigate the effect of the chemical composition of feldspar on the total ¹⁰Be production rate, major and trace element concentrations of the studied feldspar samples were analyzed. Unfortunately, giving the low compositional variability of our dataset, this issue is still pending.