Simultaneous determination of acidic,basic and alcoholic substances relating to monoamine hormones and metabolites in biological material by mass fragmentography (GC/MF)

A method is described for the simultaneous quantitative determination of monoamines and related compounds from urine and brain tissue samples in the pg-range, using a GC/MF instrument LKB-2091 provided with a multiple ion detection (MID) system and capillary columns. The simultaneous detection of “fingerprints” with fourteen and more compounds during one single GC run was achieved after the intoduction of “time gates” for the detection of the different characteristic masses. Several modifications to the LKB equipment permitted exact reproducibility of retention times, which is essential for the use of “time gates”. The detection of “fingerprints” with these acidic, basic and alcoholic substances was achieved by the extraction of the dried biological samples with silylating agents.     

碱金属和碱土金属离子在反相高效液相色谱柱上的保留机理

发现以酒石酸和吡啶二甲酸等羧酸水溶液作淋洗剂时，钠，铵，钾，镁和钙等碱金属及碱土金属离子在ＯＤＳ反相高效液相色谱柱上有明显的保留，而且相互之间能达到一定程度的分离。单独用分配或疏水作用等反相高效液相色谱的保留机理难以解释其保留行为。为此，作者提出了动态包固定相机理，即认为羧酸根阴离子因其疏水性在ＯＤＳ固定相有保留，在固定相表面形成具有羧酸基阳离子交换树脂功能的动态包覆固定相。     

Small angle X-ray scattering from lamellar phase for β-3,7-dimethyloctylglucoside/water system: comparison with β-n-alkylglucosides

Small angle X-ray scattering (SAXS) is measured for the lamellar phase in aqueous systems of 1-o-β-3,7-dimethyoctyl-D-glucopyranoside (β-Glc(Ger)), which has recently been prepared by us, 1-o-β-decyl-D-glucopyranoside (β-GlcC₁₀), and 1-o-β-octyl-D-glucopyranoside (β-GlcC₈). The repeat distance d obtained from the position of the diffraction peak does not follow the swelling law d = 2δ_hc/_hc, where δ_hc and _hc are the thickness and the volume fraction of the hydrophobic layer, respectively. This may result from the fact that δ_hc increases and, equivalently, the surface area per surfactant molecule (a_s) decreases with increasing concentration. So we calculate δ_hc and a_s from the observed d value at each concentration using the above swelling law. The half-thickness δ_hc increases in the order β-GlcC₈ < β-Glc(Ger) < β-GlcC₁₀ at a fixed concentration. On the other hand, the data on a_s for β-GlcC₁₀ and β-GlcC₈ lie on the same line and the data for β-Glc(Ger) lies above this line. These results suggest that the cross-sectional area of the geranyl chain is larger than that of the glucose headgroup. Existence of water filled defects in bilayer sheets is also discussed based on the SAXS pattern and the concentration dependence of d.     

Anomalous diffusion in a random velocity field

We construct diffusions in random velocity fields which present anomalous superdiffusive behavior. The mean square displacement can be made to have any power lawt for 1<2. Higher moments and characteristic functions are also investigated.     

Hydrothermal synthesis and intercalation behavior of a layered titanium phosphate Ti2(H2PO4)(HPO4)(PO4)2 · 0.5C6N2H16, with an extended γ-phase intercalated into organic amine

With a hydrothermal technique, a layered titanium phosphate with the formula Ti₂(H₂PO₄)(HPO₄)(PO₄)₂ · 0.5C₆N₂H₁₆ (denoted TP-J2) has been prepared by treating the Ti/H₃PO₄/H₂O/1-methylpiperazine system directly. The as-synthesized products were characterized by powder X-ray diffraction, CP-MAS solid-state ³¹P NMR spectroscopy, thermogravimetric and differential thermal analyses (TG-DTA). The structure was solved by single-crystal X-ray diffraction analysis and it presents an extended γ-phase intercalated with organic amine. Crystal data: triclinic, , a = 8.106 (2) Å, b = 8.197 (2) Å, c = 11.658 (2) Å.  = 78.32 (3)°, β = 80.85 (3)°, γ = 77.90 (3)°, Z = 2. Additionally, the intercalation behavior of TP-J2 with n-alkyl monoamine (n = 2, 3, 4, 6, 8, 10 and 12) was investigated. Owing to the strong brønsted base, N,N′-dimethylpiperazine, resides in the interlayer, it presented unusual features of TP-J2 in contrast with that of γ-Tip.     

阴离子导向组装：两个具有不同阳离子的多维Ag(I)配合物的晶体结构

Assembly of [Ag（CN）2]^- units with M（Ⅱ）-diamine complex cations [Cu（LN-N）2]^2＋, where LN-N represents L2-diaminopropane （pn） and ethylenediamine （en）, afforded two complexes, [Cu（pn）2][Ag2（CN）4] （1） and [Cu（en）2][Ag3（CN）5] （2）, which were characterized by elemental analysis, IR, UV-Vis and ESR spectra. Single crystal X-ray analyses show that these complexes have 2D and 3D architectures through silver-silver interactions and other weak interactions. The luminescence behaviors of the two complexes were also studied by means of emission spectra.     

Zinc ions and zinc sulfide particles in sol-gel zirconium phosphate synthesis, thermal behavior and X-ray characterization

Zinc ions can be exchanged in sol-gel zirconium phosphate by using the batch or hydrothermal method. The zinc materials obtained that undergo thermal treatment after complete dehydration, can rehydrate fully or partially depending on whether half or all the zinc ions are exchanged. At high temperature syntherization is evident. By flowing sulfide acid over the zinc forms, zinc sulfide particles are formed and their amount depends on the length of time of the gas flow and on the state of hydration of the original material. This is not the case in the half exchanged zinc zirconium phosphate material. The decomposition temperature of the ZnS particles depends on their position in the exchanger: whether on the surface or between the layers of the host matrix. The XRD patterns of the materials obtained are similar to those of the sol-gel zirconium phosphate. The presence of ZnS particles is evident.     

Separation of mixtures of solvents with wide bore capillary columns connected in series

The gas chromatographic separation of the components of a complex mixture of industrial solvents, not possible on a single stationary phase owing to coelution of some of the compounds, has been achieved on two serially connected wide bore capillary columns of different polarity. The analysis of a mixture of twenty five compounds was optimized using the serial gas chromatography theory of Purnell and Williams. The capacity factors of sample components measured with the two columns coupled in series were found to agree with those predicted by theory, regardless of the order in which they were connected.     

Indirect detection in reversed-phase liquid chromatography: Ion-pair retention models for ionic compounds on μ Bondapak phenyl

Summary Retention models for ionic compounds in reversed-phase ion-pair chromatographic systems have been developed on the basis of the capacity ratios of solutes and ionic mobile phase components using indirect detection. The binding to the adsorbent, μBondapak Phenyl, has been expressed by ion-pair distribution constants and tested in the retention models by non-linear regression. All the ionic compounds followed adsorption models of the Langmuir type comprising two kinds of binding sites with widely different adsorption capacities and binding constants. The results indicate certain differences between the two sites regarding the binding of cationic and anionic components, respectively.     

Indirect detection in reversed-phase liquid chromatography: Ion-pair retention models for cations on polystyrene polymers

Summary The distribution equilibria of cationic compounds in reversed-phase chromatographic systems (ion-pair chromatography) have been studied on the basis of their effect on a detectable mobile phase component. The solid phase was a polystyrene-divinylbenzene copolymer and the detectable component, a quaternary ammonium ion, 1-methylpyridine. The solutes were mono- and divalent amines and quaternary ammonium ions. The cations can be retained by ion-pair adsorption and ion exchange. Expressions for the ion-pair retention of the solutes and the mobile phase cation (system peak) have been developed assuming Langmuir distribution of ion pairs to a solid phase with one kind of binding site. The validity of the expressions has been tested by evaluation of ion-pair distribution constants using non-linear curve fitting techniques. Good agreement for the constants of common ion pairs was obtained from different kinds of capacity ratio expressions. Ion exchange retention can appear beside ion-pair retention, and it has been observed in the pH range 1.6–6.1. The effect depends not only on cations in the mobile phase, but also on the nature of the buffering systems.