Simultaneous determination of degradation products of nonylphenol polyethoxylates and their halogenated derivatives by solid-phase extraction and gas chromatography-tandem mass spectrometry after trimethylsilylation

An efficient method for the simultaneous determination of the degradation products of nonylphenol polyethoxylates (NPnEOs, n = number of ethoxy units), i.e., nonylphenol (NP), NPnEOs (n = 1-3), nonylphenoxy carboxylic acids (NPnECs, n = 1-2, number of ethoxy units plus an acetate) and their halogenated derivatives (XNP, XNP1EO and XNP1EC; X = Br or Cl), in water samples were developed. After trimethylsilylation with N,O-bis(trimethysilyl)acetamide, all the analytes were determined by gas chromatography-tandem mass spectrometry (GC-MS-MS) with electron ionization (EI). The ion peaks of [M - 85]+ of the derivatives were selected as precursor ions and their product ions showing the highest intensities were used for the quantitative analysis. The instrumental detection limits were in the range from 2.1 to 11 pg. The recoveries of the analytes from the water samples were optimized by using solid-phase extraction (SPE). The deuterated reagents of octylphenol, octylphenol monoethoxylate and octylphenoxyacetic acid were used as the surrogates. The method detection limits (500 ml water sample) using C18 SPE were from 2.5 to 18 ng/l. The recoveries from spiked pure water and the environmental water samples were greater than 78%. The method was successfully applied to environmental samples. Remarkably, the concentrations of the halogenated compounds (CINP, CINP1EO and BrNP1EO) were detected at the hundreds of ng/l levels in the Neya river.     

Reactions of oxalyl fluoride with electrophiles

The reactions of oxalyl fluoride with electrophiles in the presence of alkali metal fluoride were carried out. In the reaction with CF₃CH₂OTf (Tf=CF₃SO₂) or CH₃CH₂OTf, the synthesis of di-ether (ROCF₂CF₂OR) and mono-ether (ROCF₂COF) was achieved. The difference of the reactivities between these two compounds was discussed from the result of DFT calculations.     

Inhibitory activities of novel pyrimidine derivatives on the contact hypersensitivity reaction

In order to obtain novel topically applied anti-inflammatory compounds containing an inexpensive anti-oxidative moiety without chirality, we synthesized compound 2c derivatives having a di-tert-butylphenol moiety, and evaluated by topical administration their anti-inflammatory potentials on picryl chloride-(PC) induced contact hypersensitivity reaction (CHR) in mice. In the course of our structure-activity relationship (SAR) studies on the pyrimidine or the anti-oxidative moiety and the linker between them, the most potent compounds (10, 11) were obtained by the insertion of a C2 unit in compound 2c. The potencies of these compounds were 2-fold greater than that of 1. Compounds 10 and 11 were considered to be useful lead compounds having inexpensive anti-oxidative moieties without chirality.     

X-ray crystallographic studies and molecular calculations on 1∶1 inclusion complexes of cholic acid with acetophenone and its derivatives

Molecular calculations were applied to four channel-type inclusion complexes of cholic acid (CA) with acetophenone or its derivatives (3-, 4-fluoroacetophenone and 2-chloroacetophenone). According to the calculated results, both the total and van der Waals interaction energies between channel and included guests depend on the channel form determined by the guest species. Similarly, the channel form is responsible for the dipole moment of the channel. Further examination of the results suggests that dipole-dipole interaction does not play an important role in the determination of the guest orientation. Supplementary Data relating to this article are deposited with the British Library as Supplementary Publication No. SUP 82193 (26 pages).     

Practical expressions for the two-center multipole expansion of r

An explicit and transparent deduction of a conventional expression for the two-center multipole expansion of the Coulomb potential, r, in terms of spherical harmonics, is perfomed. An intermediate expression in the deduction is shown to be well suited for transformation into a Cartesian representation. Practical formulas are produced that allow for safe and efficient implementations in computer programs. Electrostatic interactions between two pairs of point charges are computed and the importance to include the higher multipole interactions is stressed. © 1995 John Wiley & Sons, Inc.     

Physicochemical properties of dimethylzinc,dimethylcadmium and diethylzinc

Physicochemical properties of dimethylzinc, dimethylcadmium and diethylzinc have been investigated by means of vapor pressure measurement, mass spectroscopy and gas chromatography. The saturated vapor pressure-temperature dependence of these alkyl organometallics was determined to be as follows The temperature ranges for vapor phase decomposition for deposition of each metal were clarified, and vapor-phase species released in the decompositions were investigated. These investigations on the organometallics are to provide basic material data for the establishment of organometallic chemical vapor deposition techniques for Group IIB-VI compounds.     

An improved apparatus for measuring the inhomogeneity of glasses

An improved apparatus capable of quantatively measuring the inhomogeneity of glasses within several minutes was developed as a prototype for practical use. Inhomogeneities were measured for several kinds of glass articles on the market, such as plate, bottle and optical glasses etc. and a “relative homogeneity” has been proposed for the purpose of deciding a ranking of glasses measured in comparison to the powdered single crystal of CaF₂ as a standard material of uniformity.     

The logarithmic HLS inequality for systems on compact manifolds

We prove an optimal logarithmic Hardy-Littlewood-Sobolev inequality for systems on compact m-dimensional Riemannian manifolds, for any m?2. We show that a special case of the inequality, involving only two functions, implies the general case by using an argument from the theory of linear programing.     

Pionic atom factory project in the RIBF

We are preparing for a high resolution spectroscopy of the 1s and 2s pionic states of ¹²¹Sn in the ¹²²Sn(d,³He) reaction at the incident deuteron energy of ~500 MeV. The measurement will provide accurate information on the strong interaction between the pion and the nucleus, which leads to quantitative determination of the magnitude of the quark condensate at the normal nuclear density.