Yazar "Gucer, S" seçeneğine göre listele

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    Application of loop atomizer for environmental samples by flame atomic absorption spectroscopy
    (Pergamon-Elsevier Science Ltd, 1995) Gucer, S; Karagozler, AE; Demir, M; Ozdemir, N
    Introduction of sample solutions into the flame atomic absorption spectroscopy (AAS) via electrically heated metal loops notably improves the detection limits of the technique. However, because of the low melting point of platinum (1772 degrees C) application of the loop technique is limited only to sufficiently volatile elements. In this work interference encountered with a Pt-loop atomizer is reviewed and chemical interference is found to be the most important factor limiting its applications. Therefore, a separation/enrichment step in the analytical scheme is needed not only for the enrichment of the analyte itself but also to ensure that the chemical form of the analyte in both standard and sample solutions is the same. Samples of soil extracts, fertilizers, waste water of domestic origin and air samples have been chosen to demonstrate the environmental application of the loop technique.
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    Determination of cadmium and lead in urine by flame atomic absorption spectrometry after activated carbon enrichment
    (Polskie Towarzystwo Chemiczne-Polish Chemical Soc, 1996) Aydemir, T; Gucer, S
    In this study, ammonium pyrrolidine dithiocarbamate was used as a complexing agent in the enrichment step for the determination of cadmium and lead in urine. The recoveries were above 90 % and the factors effecting recoveries, such as sample preparation, pH, amount of activated carbon, complexing reagent and the contact time,were studied. The interference effects from matrix components were compared after activated carbon enrichment. The calibration graphs were rectilinear for a range 1.2-80 mu g l(-1) and 1.6-53 mu g l(-1) for cadmium and lead, respectively. The relative standard deviations of the measurements (n=9) at concentration of 20 mu g l(-1) were 3 % for cadmium and lead. Detection limits,defined as 3 s of blanks were 1.2 mu g l(-1) for cadmium and 1.6 mu g l(-1) for lead. The untreated urine (300 ml) was adjusted to pH 6 and 4 ml of 2% APDC solution were added to complex the metals. The mixture was stirred with 500 mg activated carbon for 40 min and next was filtered. The metals were leached with nitric acid.
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    Determination of nickel in urine by flame atomic absorption spectrometry after activated carbon enrichment
    (Taylor & Francis Inc, 1996) Aydemir, T; Gucer, S
    An enrichment method is described for the determination of nickel in urine by flame atomic absorption spectrometry after preconcentration with ammonium pyrrolidine dithiocarbamate on activated carbon. The recoveries are above 90 %. The factors affecting recoveries, such as pH, amounts of activated carbon and complexing reagent, and the contact times, were also studied. The calibration graph was rectilinear for the range 2.4-80 mu g l(-1). The relative standard deviation of the measurement was 3 % for nickel at a concentration of 20 mu gl(-1) (n=9). The detection limit of the method was 0.75 mu g l(-1) when 500 ml urine was used.