Simultaneous extraction and determination of pharmaceuticals and personal care products (PPCPs) in river water and sewage by solid-phase extraction and liquid chromatography-tandem mass spectrometry

This study features the simultaneous extraction and quantification of 18 pharmaceuticals and personal care products (PPCPs). This is a pioneering method for the quantification of acetaminophen, sulfamethoxazole, diclofenac, atenolol, metoprolol, diethyltoluamide and oxybenzone in atmospheric pressure chemical ionisation mode. The method was validated for high repeatability and reproducibility with relative standard deviations less than 10%. Instrument quantification limits for PPCPs were within the range of 0.05–1.0 µg L^?1, and the method quantification limits (MQLs) for ultrapure water were within the range of 0.3–15 ng L^?1. All samples were extracted using Oasis© hydrophilic–lipophilic balanced cartridges with optimised sample size and extraction conditions. Good accuracy was demonstrated, with solid-phase extraction recoveries above 80% for most PPCPs. In environmental matrices, the MQLs for river water, sewage treatment plant (STP) effluent and STP influent were 4–25, 10–153 and 38–386.5, respectively. The method was successfully applied to investigate occurrences of persistent PPCPs in Malaysian river and sewage samples.     

Systematic study of the physicochemical properties of a homologous series of aminobisphosphonates

Aminobisphosphonates, e.g., alendronate and neridronate, are a well known class of molecules used as drugs for various bone diseases. Although these molecules have been available for decades, a detailed understanding of their most important physicochemical properties under comparable conditions is lacking. In this study, ten aminobisphosphonates, H₂N(CH₂)_nC(OH)[P(O)(OH)₂]₂, in which n = 2-5, 7-11 and 15 have been synthesized. Their aqueous solubility as a function of temperature and pH, pK_a-values, thermal stability, IR absorptions, and NMR spectral data for bothliquid (¹H, ¹³C, ³¹P-NMR) and solid state (¹³C, ¹⁵N and ³¹P-CPMAS NMR) were determined.     

Lipschitz Linearization of the Maximal Hyperbolic Cross Multiplier

Journal of Fourier Analysis and Applications - We study the linearized maximal operator associated with dilates of the hyperbolic cross multiplier in dimension two. Assuming a Lipschitz condition...     

Bessel-Gauss pulse as an appropriate mathematical model for optically realizable localized waves

We show that the field of the optically feasible luminal localized wave solutions of the scalar homogeneous wave equation can be modeled by means of Bessel-Gauss pulses. As the Bessel-Gauss pulses have a closed-form expression, this fact may be of great value in numerical simulations of various experimental situations.     

A method for the quantitative decomposition of cluster compounds and the determination of rhodium and ruthenium by flame atomic absorption spectrometry

Summary Single crystals of cluster compounds were decomposed with two different methods. The hydrogen peroxide method is easy to use and no special equipments are needed. The autoclave method has proved to be more effective and led to the complete decomposition of all tested cluster compounds. Buffering with lanthanum sulphate or KHSO₄ was used to eliminate interferences caused by foreign metal ions and phosphorus. Results of measurements after decomposition of the cluster compounds with the two methods are shown.

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Quantitative Aufspaltung von Clusterverbindungen und Bestimmung von Rhodium und Ruthenium durch Flammen-AAS

     

A convenient synthesis of nitro-substituted 1,2-benzisothiazol-3(2H)-one 1,1-dioxides (nitrosaccharins)

Nitro-substituted 1,2-benzisothiazol-3(2H)-one 1,1-dioxides (nitrosaccharins) have been synthesized by amminolysis of nitro 2-chlorosulfonylbenzoate esters. This method appears to have advantages over the original procedure of oxidation of an ortho-toluenesulfonamide.     

How small a packet of photons can be made?

In contradistinction not only to the seventy-year-old notion of poor localizability of a photon but also to a recent result of principal revisions of the notion, we demonstrate that N-photon pulsed wave functions of a specific type exhibit faster than an exponential falloff of energy and photodetection rate with distance from the pulse center. The wave functions are cylindrical and exhibit an exceptionally strong localization in two dimensions out of three. Our approach involves a “technology transfer” in the sense that, in order to tackle the problem belonging to quantum optics, we make use of results obtained recently in the study of the so-called nondiffracting localized solutions to the classical wave equation.