Lead Fractionation Analysis in Lipstick Samples by Inductively Coupled Plasma-Mass Spectrometry

A new analytical approach based on fractionation was introduced for lead in lipstick samples. Different separation techniques including n-hexane, glycerol extraction, and activated carbon adsorption were used to characterize the lipid fraction, polar and aromatic components of the samples. Additionally, artificial saliva and food stimulant extractions were used for the risk assessment studies. Trace metal levels in fractions were determined by inductively coupled plasma-mass spectrometry. Method validation parameters in the total element determinations were defined in terms of detection limits, accuracy, and precision. The limits of detection and quantification were 0.02 and 0.07 mg kg^?1 for Pb; whereas the repeatability and reproducibility of the results based on percent relative standard deviation were 3.0% and 7.2% for lead, respectively.     

Preparation and Optical Characterization of Sol-Gel Deposited Pb(Zr0.45Ti0.55)O3 Films

Homogeneous crack-free lead zirconate titanate (Pb(Zr_0.45Ti_0.55)O₃: PZT 45/55) films were prepared by a chemically modified sol-gel process using lead acetate trihydrate, zirconium n-propoxide, and titanium isopropoxide precursors. The coating solutions were modified by the addition of diethanolamine. Single and multilayer films were deposited with a 2000 rpm spin rate on fused silica and MgO(100) substrates. Multiple spin coating with an intermediate heat treatment in air at 400°C for 3 min between coatings was performed to obtain films up to 2 m in thickness. The formation of the tetragonal perovskite structure was found to depend on the intermediate firing temperature, final annealing temperature, and annealing time. A 650°C rapid thermal annealing treatment in oxygen was required to crystallize the PZT film into the perovskite structure. The films were characterized using optical spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and thermo-gravimetry and differential scanning calorimetry (TG-DSC). The optical constants of the PZT films were evaluated from spectral transmittance and reflectance measurements. Optical constants are presented over the visible and near infrared region.     

In memoriam Dr. Werner Heilig (1933-2003)

A dear friend and colleague, Dr. Werner Heilig, died last December (2-12-2003) after a short and painful illness. Dr. Heilig was well known and respected in the world-wide shock wave family due to his contributions to our understanding of shock reflection and interaction phenomena.Dr. Werner Heilig was born in Freiburg in January 1933. He received his matriculation from the Kepler-Gymnasium in Freiburg in 1953 and immediately thereafter started studying Mathematics and Physics at the Albert-Ludwigs University in Freiburg, from which he graduated in early 1958. After graduation he took an extra two years of pedagogy studies in order to qualify as a teacher of mathematics in a high school (Gymnasium), and indeed he served as a mathematics teacher in a Gymnasium from January 1961 until March 1964. A big change in his professional career took place in April 1964 when he joined the Ernst-Mach-Institute in Freiburg. Simultaneously with his new work at the Ernst-Mach-Institute he was teaching every morning from 8 to 9 oclock mathematics at the St. Ursula Gymnasium, walking to his new place of work immediately after teaching. At that time he also started his PhD studies at the University of Karlsruhe. The title of his thesis was: Theoretical and experimental studies of shock wave interaction with a sphere and a cylinder (Theoretische und experimentelle Untersuchungen zur Beugung von Stosswellen an Kugeln und Zylindern). Dr. Heilig continued this investigation, as well as other related topics, throughout his professional career. His PhD research was co-supervised by Professors Zierep and Oertel and the degree was granted in July 1969. In his dissertation he also discussed the transition criteria from regular to Mach reflection for shock wave reflection from wedges or cylinders (as is evident from Fig. 13 in his dissertation). However, since his results were not published in a reviewed journal, he has not received the credit he duly deserved.After receiving his PhD degree, Dr. Heilig started building his reputation as a careful and reliable researcher in gas dynamics, focusing his attention on shock wave reflection from wedges, shock and blast wave propagation in ducts and tunnels, and shock wave interaction with boundaries of various shapes. Until the mid 1980s most of his work was experimental, that being the strong side of the Ernst-Mach-Institute at the time. In early 1984 Dr. Heilig was assigned to introduce CFD to the Ernst-Mach-Institute. This move forced him to go from being an experimentalist to a CFD researcher, which proved to be very demanding. However, Dr. Heilig did it well, relying on his mathematical skills earned as a student in the 1950s. From the mid 1980s on he was the head of the gas dynamics group at the Ernst-Mach-Institute, and in January 1997 he became the vice-director of the Ernst-Mach-Institute, a position he held until his retirement in February 1998. Once free from formal obligations, he avidly continued his research activities, submitting proposals for (and receiving) research contracts, and writing the chapter on shock wave propagation in ducts and tunnels in the Handbook of Shock Waves which was published in 2000 by Academic Press.I first met Dr. Heilig when he attended the 12th Shock Waves Symposium, which was held in Jerusalem in July 1979, and we kept in touch ever since. We jointly proposed and conducted research on various aspects of shock wave interaction with bodies of numerous shapes, and co-authored several papers based on the results of our joint-research. It was a pleasure working with Dr. Heilig; he was a very careful scientist who was never fazed by challenging problems. His untimely death has shocked and saddened us all. May the emptiness left in our hearts by his departure be filled by gentle memories of Dr. Werner Heilig, an outstanding researcher, colleague and friend.Published online: 18 February 2005[/PUBLISHED]     

Impact of magnetic field on the nucleation and morphology of calcium carbonate crystals

The influence of static magnetic field of strength 0.75 T on the nucleation of calcium carbonate crystals has been investigated. Particle size analysis shows that magnetic field can cause marked difference in distribution. One of the major impacts of magnetic exposure is the increase in number of the critical nuclei formed. Also, magnetic field promotes the formation of parallelepipedic calcite crystals and the dissolution of the smaller crystals by Ostwald ripening mechanism. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Thermal and infrared studies of calcium malate crystals grown in diffusion limited medium

Single crystals of the title compound Ca (C₄H₅O₅)₂.10H₂O are grown in silica gel using controlled chemical reaction method. Multifaceted single crystals of size up to 8 × 4 × 2 mm³ are obtained. Powder X‐ray Diffraction (XRD) pattern of the grown crystal and the Fourier Transform Infra‐Red (FTIR) spectrum in the range 400–4000 cm^–1 are recorded. The vibrational bands corresponding to different functional groups are assigned. Thermal decomposition stages observed in the Thermo‐gravimetric (TG) and Differential Thermal Analysis (DTA) studies are discussed. A six‐stage thermal decomposition scheme is proposed for the compound. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Synthesis, characterization and nonlinear absorption of novel octakis-POSS substituted metallophthalocyanines and strong optical limiting property of CuPc

In this study, the preparation of some novel metallophthalocyanine (MPcs) complexes substituted with octakis(mercaptopropylisobutyl-POSS) functional group was achieved. By the reaction of [1-(3-mercapto)propyl-3,5,7,9,11,13,15-isobutylpentacyclo[9.5.1.1(3,9).1(5,15).1(7,13)]octasiloxane 1 with 4,5-dichloro-1,2-dicyanobenzene 2 in THF as the solvent in the presence of K2CO3 as the base, the phthalonitrile derivative 3 was synthesized. Compound 3 reacted with CoCl2 x 6H2O in ethylene glycol to furnish a novel cobalt(II) phthalocyanine . The tetramerization of 3 with urea and CuCl in the absence of solvent gave the novel Cu(II) phthalocyanine 4; while with Zn(OAc)2 x 2H2O in dry DMF gave the novel zinc(ii) phthalocyanine 6. The structures of the target compounds were confirmed by elemental analysis, UV/VIS, IR, MALDI-TOF MS and 1H NMR spectra. Nonlinear absorptions of MPcs in chloroform solution were investigated by using Z-scan measurement technique with 4 ns pulses at 532 nm wavelength. While CuPc 5 showed very high nonlinear absorption, MPcs 4 and 6 did not show considerable nonlinear absorption. Investigations of optical limiting properties of 5 revealed that this material is a very good candidate for optical limiting applications.