Effect of plasmatron excitation conditions on the determination of traces

Optimal analysis conditions can be selected and errors caused by variations in the excitation conditions can be decreased or corrected based on the results of studying the temperature distribution along the plasma torch height and correlations between the analytical signal Y and the correcting signal Z that follows the temperature variation in the plasma torch. The obtained correlations can be used to create automated feedback between the spectrum recording system and the mode control system of the plasmatron.     

Chromatographic studies of corrosion sites in metallic materials

Many types of corrosion phenomena are controlled by the ionic composition of a small volume of solution at the surface. Localized corrosion and atmospheric corrosion are two examples in which < 1 μl of solution can cause dramatic damage. Ion chromatographic (IC) techniques have been used to analyze these solutions in order to gain a better understanding of the mechanisms which govern them. Two examples are presented. The presence of minor alloying elements at localized corrosion sites in two aluminum alloys has been demonstrated, indicating non-stoichiometric dissolution of the alloy during localized corrosion. In addition, IC analysis allowed the determination of the species responsible for the atmospheric corrosion failure of electrical connectors, including their likely origin.     

Synthesis and properties of enamines of the phenanthridine series

We have synthesized secondary and tertiary enamines, derivatives of 1,2,3,4,4a,5,6,10b-octahydrophenanthridine, and we have considered the Z,E-isomerism of the enaminoesters.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1374–1377, October, 1993.     

Kinetic study of the metalation of a polystyrene model compound by the secondary butyllithium-N,N,N′,N′-tetramethylethylene diamine complex

2.5-Diphenyl hexane, a model compound of polystyrene was metalated by a complex of secondary butyllithium and N,N,N′,N′-tetramethylethylene diamine in heptane. At various times, the lithiated dimer was quenched with deuterated methanol. The deuterated compound was examined by mass spectrometry and from the deuterium content, the degree of lithiation was determined. The effects of the concentration of styrene units, secondary butyllithium and diamine on the lithiation were studied at 20 C and ?20 C. The overall rate of metalation was first order with respect to the styrene units concentration and half-order with respect to sec. butylithium-TMEDA complex concentration. The kinetic results were explained by the presence at 20 C of the 1 4 complex (1 sec. BuLi 4 TMEDA) and at ?20 C of the 1–2 complex (1 sec. BuLi 2 TMEDA).     

Isolation and separation of transplutonium and rare-earth elements in unusual oxidation states on ion exchangers in inorganic acid solutions

The behaviour of transplutonium and rare-earth elements on anion and cation exchangers in solutions of H₃PO₄ and H₂SO₄ in the presence of oxidants (KBrO₃, PbO₂, (NH₄)₂S₂O₈) and in HCl solutions in the presence of reducing agents [Zn(Hg), Eu²⁺] depending on acid concentration as well as on oxidant content and nature in solution or in resin and other factors has been studied. Effective methods of Bk(IV), Ce(IV), Am(VI), Eu(II) and Md(II) separation from trivalent TPE and REE, as well as continuous methods of isolation of isotopically pure radionuclides²⁵⁰Bk,¹⁴⁴Pr by using ion exchangers and inorganic acid solutions have been developed.     

High-performance size-exclusion chromatographic determination of the potency of biosynthetic human growth hormone products

A new high-performance size-exclusion chromatography method has been developed for the determination of potency of human growth hormone products. This method has been extensively validated and shown to correlate well with the hypophysectomized rat bioassay which has been used traditionally. The method is much more precise than the traditional bioassay and thus provides more reliable means of producing consistent biosynthetic human growth hormone batches.     

Photoelectron spectra of polyunsaturated [4,4,2]propellanes

The photoelectron spectra of the six propellanes 1 to 6 have been recorded. Those bands which correspond to ejection of an electron from a π-orbital have been assigned, using the concept of through bond and through space interaction. Homoconjugative interaction between the π-systems of the two butadiene moieties of 6 is of the same order as that of the π-orbitals in norbornadiene.     

Prospects of thermal analysis in polymer research

A survey and an analysis of the publications concerned in thermal analysis (TA) published in four renowned journals during the years 1965–1974 were performed. The published data were evaluated from three points of view: TA methods used for polymers, properties and phenomena studied by TA methods, types of polymers investigated by TA methods. From the statistical data were derived the future trends for the application of particular TA methods in polymer science.     

Anomalous behaviour of the Landé factors and the chemical shift close to the dissociation limit of the B state of molecular iodine

Resonances in a modulated light beam have been observed on five transitions in the visible band system of I₂. Landé factors g_J and chemical shifts g₁ have been measured for levels very close to the dissociation limit of the B state.     

Cl35 NQR spectra and the transmission effects in the series RSO2Cl

Conclusions It was shown by correlating the Cl³⁵ NQR frequencies with the Taft _I and _c parameters that the effect of substituents, which are either capable of conjugation (Hal, OR, NR₂) or are alkyl groups, is transmitted to the chlorine atom through the SO₂Cl group by a practically purely inductive means.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 486–488, February, 1970.