Determination of lead, copper and manganese by graphite furnace atomic absorption spectrometry after separation/concentration using a water-soluble polymer

In this study, a water-soluble polymer, polyvinylpyrrolidinone (PVP) having chelating functionalities was used for the preconcentration and separation of traces of Pb, Cu, Ve and Mn prior to their determination by graphite furnace atomic absorption spectrometry. For this purpose, the sample and the PVP solutions were mixed and the metal bound polymer was precipitated by adding the mixture onto acetone. The precipitate was separated by decantation and dissolved with water. By increasing the ratio of the volumes of sample to water used in dissolving the precipitate, the analyte elements were concentrated as needed. The concentration of trace elements was determined using graphite furnace atomic absorption spectrometry. The analyte elements in matrix free aqueous solutions were quantitatively recovered. The validity of the proposed method was checked with a standard reference material (NIST SRM 1577b bovine liver) and spiked fruit juice, sea water and mineral water samples. The analytical results were found to be in good agreement with certified and added values. Detection limits (3delta) were 1.7, 3.6 and 4.1 mug l(-1) for Pb, Cu and Mn, respectively, using 10 mul of sample volume. The method is novel and can be characterized by rapidity, simplicity, quantitative recovery and high reproducibility. (C) 2004 Elsevier B.V. All rights reserved

The use of water soluble polymers for the pre-concentration and separation of copper, lead, and chromium prior to their determination by graphite furnace atomic absorption spectrometry

In this study, a water-soluble polymer, polyacrylamide containing R-(+)-Cysteine end groups was used for the separation and preconcentration of copper, lead and chromium prior to their analysis by graphite furnace atomic absorption spectrometry. The sample and polymer solution were mixed and metal-bound polymer was precipitated upon addition of acetone. The precipitate was separated from solution and dissolved directly with distilled water. By this way. analyte elements were again transferred into the liquid phase and analyzed by graphite furnace atomic absorption spectrometry. The advantages and disadvantages of the method compared to those of the traditional batch and column techniques using water insoluble solid materials were described in all aspects. The method is simpler and faster compared to other preconcentration and separation techniques. Recoveries from matrix free aqueous solutions are higher than 96% and relative standard deviations were lower than 3%

Slurry analysis after lead collection on a sorbent and its determination by electrothermal atomic absorption spectrometry

In this study, in order to eliminate the drawbacks of elution step and to reach higher enrichment factors, a novel preconcentration/separation technique for the slurry analysis of sorbent loaded with lead prior to its determination by electrothermal atomic absorption spectrometry was described. For this purpose, at first, lead was collected on ethylene glycol dimethacrylate methacrylic acid copolymer (EGDMA-MA) treated with ammonium pyrolidine dithiocarbamate (APDQ by conventional batch technique. After separation of liquid phase, slurry of the sorbent was prepared and directly pipetted into graphite furnace of atomic absorption spectrophotometer. Optimum conditions for quantitative sorption and preparation of the slurry were investigated. A 100-fold enrichment factor could be easily reached

Postpartum-onset obsessive-compulsive disorder: Incidence, clinical features, and related factors

Conclusions: This study suggests that the puerperium is a risk period in terms of new-onset OCD and that avoidant and obsessive-compulsive personality disorders predict PPOCD