Dióda lézeres spektroszkópiai módszerek = Methods of diode laser spectroscopy

A projekt során a diódalézeres atomspektroszkópia három részterületén értünk el kísérleti eredményeket. 1.) egy külső rezonátoros (ECDL), piezoelektromos finomhangolású, a felharmonikus keltésének módszerén alapuló (SHG) diódalézeres kísérleti rendszert építettünk meg és jellemeztünk. 2.) Atomabszorpciós és atomfluoreszcenciás elven működő diódalézeres mérőberendezést (DLAAS illetve DLIF) építettünk egy induktív csatolású plazma atomforrás (ICP) köré, amelyet optimálás után plazmadiagnosztikai és elemanalitikai célokra alkalmaztunk. Az alkalmazások során alkálifémek és halogén elemek meghatározásának lehetőségét vizsgáltuk környezeti mintákban. 3.) Hullámhossz-modulációs diódalézeres atomabszorpciós spektroszkópiás (WM-DLAAS) mérőberendezést építettünk egy láng atomforrás köré, majd a kísérleti illetve jeldetektálási koncepciók optimálása után meghatároztuk a rendszer teljesítményjellemzőit Li és Rb elemek mérése esetén. További jelentős eredményeket értünk el kapcsolódó lézeres atomspektroszkópiai területeken is. | Within the frames of the project, we achieved experimental results in three areas of diode laser atomic spectroscopy. 1.) We built and characterized the performance of an extended cavity diode laser arrangement (ECDL) with piezoelectric fine tuning capability and frequency upconversion by second harmonic generation (SHG). 2.) We constructed a diode laser atomic absorption (DLAAS) and a diode laser induced fluorescence (DLIF) spectroscopic measurement system around an inductively coupled plasma (ICP) atom source. Using this system, we performed plasma diagnostic studies and elemental analytical applications. During the course of the latter, we concentrated on the feasibility of the determination of alkali and halogen elements in samples of environmental origin. 3.) We set up a wavelength modulation diode laser atomic absorption spectroscopy system (WM-DLAAS) around a flame atom source, and determined its analytical figures of merit for the case of the measurement of Li and Rb, after the optimization of experimental parameters and signal detection methods. Significant other results were also achieved in connected areas of laser atomic spectroscopy

Studies on column adsorption of arsenic (V) from a real water on dehpa-impregnated XAD-8 resin

Arsenic contamination of drinking water is a widespread problem of international interest. Arsenic is released from the soil through natural processes or due to human activities. In the paper was studied the possibility of removal of arsenic from drinking water using a column filled with Amberlite XAD-8 resin impregnated with di-(2-ethylhexyl) phosphoric acid (DEHPA). The efficiency of arsenic removal from water was established by studying the dependence of arsenic residual concentration and arsenic removal degree on the volume of the water passed over the adsorbent material. The adsorption process had an efficiency of -90% and the arsenic residual concentration was smaller than 10 pg/L. The studies concerning the influence of other ions present in water (Na+, K+, Ca2+, Mg2+, Fen+, Mnn+, NO2", N H /, NO3', PO43', CF) showed that these ions do not interfere with arsenic adsorption process

Use of impregnated resins as adsorbents in view of heavy metals removal from aqueous solutions

The presence of heavy metal ions in environment is a major concern because of their toxicity to many life forms. Heavy metal ions can be removal from water by adsorption on solid support. In the present work, we tested the adsorption of metal ions on solvent impregnated resin (SIR). Di-(2-ethylhexyl)-phosphoric acid (D2EHPA) has been chosen as an extractant for the purpose of this study. The interaction between XAD4 resin and D2EHPA was evaluated by physico-chemical methods of analysis (EDX and SEM). The experimental studies on adsorption of metal ions were carried out on Pb2+, Cu2+, Cd2+, Cr3+, Ni , Fe3+, Zn2+ and Ca2+. A separation method was developed for metals ions and was investigated the influence of contact time on the residual concentration of metal ions, on their removal efficiency and on the adsorption capacity of resin towards metal ions

Optimization of dispersive liquid-liquid microextraction for polyethylene glycol-coated gold and silver nanoparticles

The use of polyethylene glycol modified nanoparticles is becoming an interesting topic since they present a very good stability in biological media. However, the effects of these nanoparticles on organisms are still unclear, so it is necessary to monitor their presence in bodily fluids, such as plasma or urine. Single-particle ICP-MS is a versatile tool to simultaneously detect and characterize nanoparticles in aqueous media, but a previous extraction step is necessary when analyzing complex samples due to the occurrence of matrix effects. In this work, an ultrasound assisted dispersive liquid-liquid microextraction method based on the use of chloroform as extracting solvent has been optimized for the extraction, characterization, and quantification of polyethylene glycol modified gold and silver nanoparticles in aqueous media. So far, we could achieve extraction efficiencies higher than 75% for both types of nanoparticles studied. We believe that with further optimization, the extraction can be made quantitative

Trace element distribution mapping in pharmaceutical and biological samples using laser-induced breakdown spectroscopy

Laser-induced breakdown spectroscopy (LIBS) has numerous advantages like determination of ppb-ppm level concentrations, microdestructivity, the ability of making high resolution laterally (µm) or depth-resolved (100 nm) analysis, sensitive measurement of heavy and light elements and direct analysis of solid samples with minimal sample preparation. The aim of the present work was to demonstrate that LIBS is a suitable analytical technique to assess the trace element distribution of pharmaceutical and biological samples. As test samples, we used specimens of chickpea milkvetch (Astragalus cicer), a perennial plant with excellent nutritional value and a commercially available dietary supplement pill (Supradyn)

The effect of the plasma sampling depth and the flow rate of the aerosol dilution gas on the performance of single particle inductively coupled plasma mass spectrometry (SP-ICP-MS) measurements

Single Particle Inductively Coupled Plasma Mass Spectroscopy is a modern technique available for the characterization of nanoparticles. Optimization of the measurement conditions can increase the potential of the technique, especially with regards to the minimum detectable particle size (typically ca. 15 nm). To this end, in this work we explored the effects of changing the (interface) sampling depth and the on-line aerosol dilution by the High Matrix Introduction (HMI) function on an Agilent 7700X ICP-MS