Paper Analysis: Nondestructive and Destructive Analytical Methods

Abstract: Forensic examination and dating documents is an important issue in our society, because documents are used throughout our lives to record everything we do. It starts with our birth certificate and ends with our death certificate. Between them there are receipts, leases, deeds, contracts, checks, wills, sales agreements, and medical records. The validity of all of these documents is often questioned during litigation. This study describes the use of nondestructive analysis of paper (Fourier transform infrared [FTIR] spectroscopy using an attenuated total reflectance [ATR] technique, Raman spectroscopy) and destructive analysis of paper (microscopic analysis of fibers, FTIR analysis of paper ash, inductively coupled plasma–mass spectrometry [ICP-MS]). The results are discussed in detail.     

Vibrational Spectroscopy in Clinical Analysis

Abstract: Vibrational spectroscopy includes several different techniques, the most important of which are mid-infrared (IR), near-IR, and Raman spectroscopy. Raman and mid-IR spectroscopy are complementary techniques and usually both are required to completely measure the vibrational modes of a molecule. Vibrational spectrometry covers a series of well-established analytical methodologies suitable to be employed for both qualitative and quantitative purposes. In the first part of this review, we will focus on theoretical aspects related to vibrational techniques; in the second part, the most important papers, published during the period 2005–2014, related to clinical analysis performed with vibrational spectroscopy techniques will be critically discussed.     

Analytic inner shell internal conversion coefficients for screened Coulomb potentials

An analytic method is presented for evalution of internal conversion coefficients (ICC) in inner shells of neutral or ionized atoms. Analytic formulas for ICC are given which include electron screening and static nuclear size effects. Predictions have also been obtained from these formulas for point Coulomb ICC or for screening effects included only in bound state normalization. Very good agreement with full numerical calculations is found, except in those cases where the formation region of the ICC is not well inside the atom. While the discussion in this paper concerns mediumZ elements (30<Z<80) and not too low energy, the method can be extended to other situations. The method is suited also for ICC of the inner shells of ionized atoms, even for very high degree of ionization.     

Determination of sulpha-drugs with ion-selective membrane electrodes

A liquid-membrane mercury(II)-sensitive electrode is used for determination of various sulpha drugs by addition of excess of mercuric nitrate and potentiometric back-titration of the surplus mercury(II) with EDTA. The performance of the electrode is compared with that of an Ag(2)S crystal-membrane electrode. Attempts to prepare a sulphamethoxazole-sensitive electrode failed.     

Amitriptyline-selective plastic membrane sensors and their pharmaceutical applications.

The construction and general performance characteristics of potentiometric amitriptyline-plastic membrane sensors, based on ion-pair complexes with triphenylstilbenylborate and tetra(2-chlorophenyl)borate, respectively, are described. Both electrodes show near-Nernstian responses over the range 1 x 10(-2)-7 x 10(-6) mol dm-3 with a detection limit of about 5 x 10(-6) mol dm-3. The electrodes proved useful in the determination of amitriptyline hydrochloride in pure drug substances and pharmaceutical preparations. They were also applied to the determination of content uniformity and dissolution rate of sugar-coated amitriptyline tablets. The physical processes were numerically simulated by typical equations.     

New BF(-)(4) and ClO(-)(4)-selective membrane electrodes and their pharmaceutical applications

The construction and general performance characteristics of ion-selective membrane electrodes sensitive to BF(-)(4) and ClO(-)(4) anions, respectively, are described. All electrodes show near-Nernstian responses in the range 10(-2) -10(-5)M. The selectivity of the electrodes to a number of organic and inorganic anions are reported. The electrodes are useful in the potentiometric determination of a few pharmaceutical preparations. The method is simple, rapid and does not require prior sample pre-treatment.     

Intensity measurements on Σ-hyperonic and kaonic atoms

σ-hyperonic X-ray lines have been observed in 8 elements and their intensities as well as those of the accompaning kaonic X-ray lines have been determined. The σ-atomic cascade has been found to be similar to those of other exotic atoms. The production of σ^? hyperons per stoppedK ^? has been measured by comparing their X-ray intensities. For the first time the intensity attenuation due to the strong absorptive σN interaction could be measured in four cases, and simple optical model calculations have been performed in order to reproduce the data.     

Syntheses and reactions of some fluorinated dienes,cyclobutenes and furans

There are many reports¹ of the pyrolysis of fluorinated organic compounds, including the defluorination of cyclic fluorocarbons over iron to give aromatic compounds. Extending this technique we have investigated the flow pyrolysis of some readily accessible unsaturated fluorocarbons, such as I, II, and III, and found these to be synthetically

useful routes to fluorinated dienes, cyclobutenes, and furans. Pyrolyses were carried out using a nitrogen flow over platinum, iron or caesium fluoride heated at 430–700°. The various products can all be rationalized in terms of intermediate allylic radicals, and the solid substrate influences which allylic radicals are formed.We are also investigating the chemistry of those now accessible compounds, such as IV, V, and VI, and some of the preliminary results are described.

For example the fluoride ion induced dimerisation of IV gave two major products VII and VIII via a particular interesting mechanism.

     

ChemInform Abstract: The Ground-State Potential Energy Surface of Diazene

has been studied by using a complete active space MCSCF wave function generated by distributing eight electrons among eight orbitals.