Chemistry / Kimya
Permanent URI for this collectionhttps://hdl.handle.net/11147/4072
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Article Citation - WoS: 2Citation - Scopus: 3Determination of Arsenic by Hydride Generation—laser-Induced Breakdown Spectroscopy: Characterization of Interelement Interferences(Taylor and Francis Ltd., 2018) Bölek, Deniz; Ünal Yeşiller, Semira; Yalçın, ŞerifeIn this study, interelement interferences were evaluated for the determination of arsenic in aqueous samples through laser-induced breakdown spectroscopy (LIBS) hyphenated with a hydride generation sample introduction system. Optimum instrumental and chemical parameters were selected and variation in LIBS signal intensity was recorded for As solution in the presence of comparable concentrations of interfering elements. No significant change in the signal intensity of As(I) 228.8 nm line was observed in the presence of alkali/alkali earth metals; however, the presence of hydride-forming elements has shown a noticeable decrease in the line emission strength of arsenic. The least variation in arsenic signal was observed in the presence of Ge, the most volatile of all. However, the signal has decreased to a greater extent in the presence of Sn, Sb, and Pb. The presence of interfering elements on electron temperature and electron number density of arsenic plasma has also been studied. Plasma temperatures calculated using both As and Ar emission lines in the Boltzmann equation were similar, being around 5000 K. The McWhirter criterion for stationary and homogenous plasmas was utilized for the establishment of the local thermodynamic equilibrium under the plasma conditions studied. Applicability of the technique for multielemental analysis of water samples was tested through spiking experiments. Arsenic signal showed 26% decrease in the multielemental mixture solution. LIBS is among a few atomic spectroscopic techniques that facilitate rapid and simultaneous multielemental analysis without extensive sample preparation steps. However, the analytical performance of the technique still requires more serious efforts to compete with other conventional techniques for routine analysis of environmental samples.Article Citation - WoS: 23Citation - Scopus: 22Optimization of Chemical and Instrumental Parameters in Hydride Generation Laser-Induced Breakdown Spectrometry for the Determination of Arsenic, Antimony, Lead and Germanium in Aqueous Samples(Elsevier Ltd., 2013) Ünal Yeşiller, Semira; Yalçın, ŞerifeA laser induced breakdown spectrometry hyphenated with on-line continuous flow hydride generation sample introduction system, HG-LIBS, has been used for the determination of arsenic, antimony, lead and germanium in aqueous environments. Optimum chemical and instrumental parameters governing chemical hydride generation, laser plasma formation and detection were investigated for each element under argon and nitrogen atmosphere. Arsenic, antimony and germanium have presented strong enhancement in signal strength under argon atmosphere while lead has shown no sensitivity to ambient gas type. Detection limits of 1.1mgL-1, 1.0mgL-1, 1.3mgL-1 and 0.2mgL-1 were obtained for As, Sb, Pb and Ge, respectively. Up to 77 times enhancement in detection limit of Pb were obtained, compared to the result obtained from the direct analysis of liquids by LIBS. Applicability of the technique to real water samples was tested through spiking experiments and recoveries higher than 80% were obtained. Results demonstrate that, HG-LIBS approach is suitable for quantitative analysis of toxic elements and sufficiently fast for real time continuous monitoring in aqueous environments.