Atomic layer deposition, characterization, and growth mechanistic studies of TiO2 thin films.

Two heteroleptic titanium precursors were investigated for the atomic layer deposition (ALD) of titanium dioxide using ozone as the oxygen source. The precursors, titanium (N,N'-diisopropylacetamidinate)tris(isopropoxide) (Ti(O(i)Pr)3(N(i)Pr-Me-amd)) and titanium bis(dimethylamide)bis(isopropoxide) (Ti(NMe2)2(O(i)Pr)2), exhibit self-limiting growth behavior up to a maximum temperature of 325 °C. Ti(NMe2)2(O(i)Pr)2 displays an excellent growth rate of 0.9 Å/cycle at 325 °C while the growth rate of Ti(O(i)Pr)3(N(i)Pr-Me-amd) is 0.3 Å/cycle at the same temperature. In the temperature range of 275-325 °C, both precursors deposit titanium dioxide in the anatase phase. In the case of Ti(NMe2)2(O(i)Pr)2, high-temperature X-ray diffraction (HTXRD) studies reveal a thickness-dependent phase change from anatase to rutile at 875-975 °C. X-ray photoelectron spectroscopy (XPS) indicates that the films have high purity and are close to the stoichiometric composition. Reaction mechanisms taking place during the ALD process were studied in situ with quadrupole mass spectrometry (QMS) and quartz crystal microbalance (QCM).

Developing of LC/MS method with microwave assisted extraction for determination of methadone and it major metabolite (EDDP) in the blood of patients of methadone maintenance treatment.

Opium derivatives as the addictive substances cause many medical and social problems. In treatment of opiates addiction except psychotherapy a long time pharmacotherapy with methadone or buprenorphine are apply. In a recent study both moderate- and high-dose methadone treatment resulted in reductions in illicit opioid use. The aim of the study was develop fast high sensitive liquid chromatography coupled with mass spectrometry for determination of methadone and EDDP after microwave assisted extraction. Developed method for methadone and EDDP determination were linear over the range 5 to 1000 ng/ml for methadone and its metabolite. The method exhibit a good intra and inter day precision, the microwave assisted extraction was also satisfactory with recovery superior to 80%. The mean concentration of methadone in plasma of patients receiving 40 mg of drug per day was 194 ng/ml but in second group (receiving 90 mg of methadone/day) 263 ng/ml. The ratio of the doses was 2.25 but for methadone concentration only 1.36. The much higher ratio (3.25) of concentrations was noticed for EDDP. This observation can support opinion other authoress about polymorphism of methadone pharmacokinetics and pharmacodynamics.