Global Water Mapping, Requirements, and Concerns over Water Quality Shortages

Water is a blessing and reason forsurvival on earth for human beings. Without water, it is not difficult to live on earth, but it is impossible. Water fulfills domestic, drinking, agricultural, and industrial requirements and makes everything useful for us. Unfortunately, rapid increase in population, unplanned agriculture practices, and industrial sector have become a serious issues for environment and for future needs. Water will be a very important issue for next generations to face. Safe water access up to 50−100 liters per day for drinking and sanitation is a right of every human being, recognized by the United Nations General Assembly in July 2010. Approximately, six billion people may suffer from scarcity of clean water by 2050. The agriculture sector is the largest consumer of freshwater around 70% followed by industry and domestic of 19 and 11%, respectively. The global demand for water is gradually increasing by 1% per year. Global demand for water is predicted to increase by 55% between the years 2000 and 2050. Existing global water demand has been projected to about 4600 km3 every year and estimation may increase up to 20−30%, in range of 5500−6000 km3 every year by 2050

DETERMINATION OF CADMIUM AND LEAD IN WATER AND FOOD BY ORGANIC DROP MICROEXTRACTION AND FLAME ATOMIC ABSORPTION SPECTROMETRY

Single-solidified floating organic drop microextraction was used for the preconcentration and determination of Cd(II) and Pb(II). The procedure employed 1-(2-pyridylazo)-2-naphthol as a chelating agent, 1-undecanol as the extractant solvent, and methanol as the dispersive solvent. Factors influencing the recovery of Cd(II) and Pb(II) such as the pH, volume of extractant, volume of ligand, volume of dispersant, and stirring time were optimized by Plackett Burman design. In order to complete the optimization, a central 2(3) +star orthogonal composite design was applied. The limits of detection for Cd(II) and Pb(II) were 0.15 and 0.52gL(-1). The validation of the procedure was evaluated by the analysis of TMDA 70 Fortified Water and NCSDC-73349 Bush Branches certified reference materials. The determined values were in good agreement with the certified values. The single-solidified floating organic drop microextraction method was employed for the determination of cadmium and lead in water, vegetables, and fruit

Preconcentration/separation of lead at trace level from water samples by mixed micelle cloud point extraction

A mixed micelle-mediated cloud point extraction procedure was developed for lead. Triton-X114 and benzyldimethyl hexadecyl-ammonium chloride were used as mixed micellar medium. Lead(II) was reacted with 4-(2-pyridylazo) resorcinol at pH 6.0 to form hydrophobic chelates. The parameters including pH, ligand volume, concentrations of surfactants and centrifugation time were optimized. The effect of some common ions was also tested. The limit of detection was 1.15 mu g L-1 with preconcentration factor of 50. The accuracy of method was evaluated by the analysis of certified reference materials. The method was successfully applied to determination of levels of lead in water samples. (C) 2015 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved

Spectrophotometric determination of uranium using chromotrope 2R complexes

A simple, fast and reliable spectrophotometric method for the determination and microextraction of trace amounts of uranium using chromotrope 2R as a chelating agent and 1-butyl-3-methylimidazolium hexafluorophosphate ionic liquid (IL) was used as an extractant solvent. Influence variables such as pH, volume of ligand and IL were inspected by full factorial design. In the view of Pareto chart a contour plot was studied to examine the significant variables and their interactions. The detection limit and the preconcentration factor were found to be 0.87 and 50 mu g L-1, respectively. The developed method was successfully applied to ore samples

A pipette tip multiwalled-carbon nanotube solid-phase extraction of lead in water and hair samples: application of the statistical Taguchi method to optimise the experimental variables

A pipette tip multiwalled-carbon nanotube solid-phase extraction (PT-MWCNTs-SPE) coupled with flame atomic absorption spectrometry (FAAS) was developed for extraction and determination of lead in hair samples. In this study, PT-MWCNTs-SPE cartridge, assembled by packing MWCNTs as a sorbent into a 100-mu L pipette tip. Taguchi's method (L9 orthogonal array (OA)) as a statistical design of experiments was employed to optimise the factors and experiments that affected on the recovery of Pb(II). Under the optimum conditions, four parameters such as pH (P), volume of ligand (AL), sorbent amount (SA) and eluent concentrations of HNO3 (EC) were chosen as important affecting parameters. The limit of detection (LOD) of this method was 0.86 mu gL(-1) with relative standard deviations (RSD) <= 3% for Pb(II). Afterwards, the accuracy of proposed method was evaluated by TMDA 53.3 fortified water and NCS ZC 81002b human hair certified reference materials. The procedure was applied to lead contents of water and hair samples

Separation-preconcentration of nickel and lead in food samples by a combination of solid-liquid-solid dispersive extraction using SiO2 nanoparticles, ionic liquid-based dispersive liquid-liquid micro-extraction

A microextraction method for the determination of nickel and lead using solid-liquid-solid dispersive extraction followed by ionic liquid-based dispersive liquid-liquid microextraction (SLSDE-ILDLLME) was presented. It was applied to the extraction of nickel and lead from food samples. Ammonium pyrrolidine dithiocarbamate (APDC) as complexing agent, [C4MIM][PF6] as ionic liquid, SiO2 as nanoparticles and 2 mol L-1 HNO3 as eluent were used. Several important parameters such as amount of IL, extraction time, pH and volume of the complexing agent were investigated. The quantitative recoveries were obtained at pH 7.0 for analytes. Under the optimum conditions, the limits of detection (LODs) calculated using blank, 3(Sd)(blank)/m were 0.17 for Ni(II) and 0.79 mu g L-1 for Pb(II) for aqueous solutions with 125 enrichment factor (EF). The limit of detections of the analyte ions (3(Sd)(blank)/m) for solid samples were 0.09 mu g g(-1) (Ni) and 0.40 mu g g(-1) (Pb). The accuracy of the proposed method was confirmed by the analysis of standard reference material (1577c bovine liver) and spiked recovery test. The proposed method was applied to determine nickel and lead levels in chicken, fish and meat samples. (C) 2014 Elsevier B.V. All rights reserved

Ligandless ultrasonic-assisted and ionic liquid-based dispersive liquid-liquid microextraction of copper, nickel and lead in different food samples

A simple and rapid ultrasonic assisted-ionic liquid based-liquid-liquid microextraction (UA-IL-DLLME) method has been developed for the enrichment and separation of Cu(II), Ni(II) and Pb(II). A two level factorial design was used to determine the effect of key factors such as pH, volume of ionic liquid (IL), carbon tetra chloride (CCl4) and sonication time (St). 1-Butyl-3-methylimidazolium hexafluorophosphate ([C4MIM][PE6]) and CCl4 were used as an extractant and dispersant solvent, respectively. The accuracy of the proposed method was evaluated by analysing of SRM Apple Leaves 1515 certified reference material. The limits of detections (LODs) were 0.17 mu g/L, 1149 mu g/L and 0.95 mu g/L for Cu, Ni and Pb, respectively. The enrichinent factor (EF) was 100. The method has been successfully applied for the analysis of the content of Cu, Ni and Pb in spice, vegetable and fruit samples by flame atomic absorption spectrometry (FAAS). (C) 2014 Elsevier Ltd. All rights reserved

Ligandless surfactant mediated solid phase extraction combined with Fe3O4 nano-particle for the preconcentration and determination of cadmium and lead in water and soil samples followed by flame atomic absorption spectrometry: Multivariate strategy

In the present study, a microextraction technique combining Fe3O4 nano-particle with surfactant mediated solid phase extraction ((SM-SPE)) was successfully developed for the preconcentration/separation of Cd(II) and Pb(II) in water and soil samples. The analytes were determined by flame atomic absorption spectrometry (FAAS). The effective variables such as the amount of adsorbent (NPs), the pH, concentration of non-ionic (TX-114) and centrifugation time (min) were investigated by Plackett-Burman (PBD) design. The important variables were further optimized by central composite design (CCD). Under the optimized conditions, the detection limits (LODs) of Cd(II) and Pb(II) were 0.15 and 0.74 mu g/L, respectively. The validation of the proposed procedure was checked by the analysis of certified reference materials of TMDA 53.3 fortified water and GBW07425 soil. The method was successfully applied for the determination of Cd(II) and Pb(II) in water and soil samples. (C) 2014 Elsevier Inc. All rights reserved

Use of Modified Diethylamine Phosphorus-containing Polymer for Solid Phase Extraction of Cobalt and Lead in Fruit Samples Employing Flame Atomic Absorption Spectrometry

A solid phase extraction (SPE) method was developed using 1-(2-thiazolylazo)-2-naphthol (TAN) as a chelating reagent and a modified diethylamine phosphorus-containing polymer (DPCP) as the adsorbent which was loaded into the column for preconcentration of trace amounts of cobalt and lead in fresh fruit samples. A preliminary experiment was carried out at pH 6.0, which is best suited for optimization and accumulation of the metal ions from the column After phase separation/elution, the enriched analytes in the final solution were determined by flame atomic absorption spectrometry (FAAS). Interfering ions were also studied which were found not to have any significant interference effect on the % recovery of the metals ions. A preconcentration factor of 10 was obtained. The detection limits for the fresh fruit samples were 4.4 mu g L-1 for Co and 1.04 mu g L-1 for Pb. Validation of the developed method was performed using standard reference material SRM 1515 Apple Leaves. The proposed procedure is simple, precise, accurate, and inexpensive