Online Automated Micro Sample Preparation for High-Performance Liquid Chromatography

Sample preparation is one of the most labor-intensive and time-consuming operations in sample analysis. Sample preparation strategies include the exhaustive or non-exhaustive extraction of analytes from matrices. Online coupling of sample preparation with the separation system is regarded as an important goal. In-tube solid-phase microextraction (SPME) is an effective sample preparation technique that uses an open tubular fused-silica capillary column as an extraction device. In-tube SPME is useful for trace enrichment, automated sample cleanup, and rapid online analysis. Moreover, this method can be used to determine the analytes in complex matrices by direct sample injection or merely by simple sample treatment such as filtration. In-tube SPME is frequently combined with high-performance liquid chromatography (HPLC) using online column-switching techniques. Various operating systems and new sorbent materials have been reported to improve extraction efficiency, such as sorption capacity and selectivity. This chapter discusses efficient micro sample preparation techniques for HPLC, especially online automated in-tube SPME

(2,7-Dimeth­oxy­naphthalen-1-yl)(3-nitro­phen­yl)methanone

The title compound, C19H15NO5, has an intra­molecular C—H⋯O=C hydrogen bond between a naphthalene H atom and the O atom of the carbonyl group. The inter­planar angle between the naphthalene ring system and the benzene ring is 69.59 (5)°. The dihedral angle between the bridging carbonyl C—C(=O)—C plane and the naphthalene ring system is 61.02 (6)°, which is far larger than that between the bridging carbonyl plane and the benzene ring [12.68 (7)°]. The nitro group is slightly out of the plane of the benzene ring [O—N—C—C torsion angle = 4.97 (17)°]. In the crystal, the packing is mainly stabilized by C—H⋯O inter­actions between an H atom of the benzene ring and an O atom of the nitro group

1,8-Bis(4-amino­benzo­yl)-2,7-dimeth­oxy­naphthalene

The title compound {systematic name: [8-(4-aminobenzoyl)-2,7-dimethoxynaphthalen-1-yl](4-aminophenyl)methanone}, C26H22O4N2, possesses crystallographically imposed twofold symmetry, with two C atoms lying on the rotation axis. In the crystal, the mol­ecules inter­act through inter­molecular N—H⋯O hydrogen bonds between the amino and meth­oxy groups on the naphthalene ring systems and N—H⋯π inter­actions between the amino groups and the naphthalene rings. Furthermore, weak C—H⋯O hydrogen bonds and π–π stacking inter­actions between the benzene rings are observed. The centroid–centroid and inter­planar distances between the benzene rings of the aroyl group and the naphthalene ring systems of adjacent mol­ecules are 3.6954 (8) and 3.2375 (5) Å, respectively. The dihedral angle between the mean planes of the benzene ring and the naphthalene ring system is 83.59 (5)°. The benzene ring and the carbonyl group in the benzoyl unit are almost coplanar [C—C—C—O torsion angle = 175.91 (10)°]

(4-Bromo­phen­yl)(3,6-dimeth­oxy-2-naphth­yl)methanone

In the title compound, C19H15BrO3, the dihedral angle between the naphthalene ring system and the benzene ring is 62.51 (8)°. The bridging carbonyl C—C(=O)—C plane makes dihedral angles of 47.07 (6)° with the naphthalene ring system and 24.20 (10)° with the benzene ring. A weak inter­molecular C—H⋯O hydrogen bond exists between the H atom of one meth­oxy group and the O atom of the other meth­oxy group in an adjacent mol­ecule. The crystal packing is additionally stabilized by two types of weak inter­molecular inter­actions involving the Br atom, C—H⋯Br and Br⋯O [3.2802 (14) Å]

Electronic Structure and Electron Correlation in LaFeAsO_{1-x}F_x and LaFePO_{1-x}F_x

Photoemission spectroscopy is used to investigate the electronic structure of the newly discovered iron-based superconductors LaFeAsO_{1-x}F_x and LaFePO_{1-x}F_x. Line shapes of the Fe 2p core-level spectra suggest an itinerant character of Fe 3d electrons. The valence-band spectra are generally consistent with band-structure calculations except for the shifts of Fe 3d-derived peaks toward the Fermi level. From spectra taken in the Fe 3p -> 3d core-absorption region, we have obtained the experimental Fe 3d partial density of states, and explained it in terms of a band-structure calculation with a phenomenological self-energy correction, yielding a mass renormalization factor of ~< 2.Comment: 4 pages, 5 figure

Photogrammetry-based Texture Analysis of a Volcaniclastic Outcrop-peel: Low-cost Alternative to TLS and Automation Potentialities using Haar Wavelet and Spatial-Analysis Algorithms

Numerous progress has been made in the field of applied photogrammetry in the last decade, including the usage of close-range photogrammetry as a mean of conservation and record of outcrops. In the present contribution, we use the SfM-MVS method combined with a wavelet decomposition analysis of the surface, in order to relate it to morphological and surface roughness data. The results demonstrated that wavelet decomposition and RMS could provide a rapid insight on the location of coarser materials and individual outliers, while arithmetic surface roughness were more useful to detect units or layers that are similar on the outcrop. The method also emphasizes the fact that the automation of the process does not allows clear distinction between any artefact crack or surface change and that human supervision is still essential despite the original goal of automating the outcrop surface analysis

Iron and Nickel Line Diagnostics for the Galactic Center Diffuse Emission

We have observed the diffuse X-ray emission from the Galactic center (GC) using the X-ray Imaging Spectrometer (XIS) on Suzaku. The high-energy resolution and the low-background orbit provide excellent spectra of the GC diffuse X-rays (GCDX). The XIS found many emission lines in the GCDX near the energy of K-shell transitions of iron and nickel. The most pronounced features are FeI K alpha at 6.4 keV and K-shell absorption edge at 7.1 keV, which are from neutral and/or low ionization states of iron, and the K-shell lines at 6.7 keV and 6.9 keV from He-like (FeXXV K alpha) and hydrogenic (FeXXVI Ly alpha) ions of iron. In addition, K alpha lines from neutral or low ionization nickel (NiI K alpha) and He-like nickel (NiXXVII K alpha), and FeI K beta, FeXXV K beta, FeXXVI Ly beta, FeXXV K gamma and FeXXVI Ly gamma are detected for the first time. The line center energies and widths of FeXXV K alpha and FeXXVI Ly alpha favor a collisional excitation (CE) plasma for the origin of the GCDX. The electron temperature determined from the line flux ratio of FeXXV K alpha / FeXXV K beta is similar to the ionization temperature determined from that of FeXXV K alpha /FeXXVI Ly alpha. Thus it would appear that the GCDX plasma is close to ionization equilibrium. The 6.7 keV flux and temperature distribution to the galactic longitude is smooth and monotonic,in contrast to the integrated point source flux distribution. These facts support the hypothesis that the GCDX is truly diffuse emission rather than the integration of the outputs of a large number of unresolved point sources. In addition, our results demonstrate that the chemical composition of Fe in the interstellar gas near the GC is constrained to be about 3.5 times solar.Comment: 11 pages, 19 figures. Accepted for publication in PASJ Suzaku Special Issue (vol. 59 sp. 1

No Different Sensitivity in Terms of Whole-Body Irradiation between Normal and Acatalasemic Mice

To elucidate the radiosensitivity of an acatalasemic mouse, we examined the time and dose-dependency in the survival rates, the lymphocytes and the intestinal epithelial cells, and the antioxidant function after 3.0 to 12.0 Gy whole body irradiation. Results showed that no significant differences between acatalasemic mice and normal mice were observed in the survival rates and the histological changes in spleens and small intestine after each irradiation. The catalase activities in livers and spleens of acatalasemic mice were significantly lower than those of normal mice and the glutathione peroxidase activity in livers of acatalasemic mice was significantly higher than that of normal mice. At 10 days after 6.0 Gy irradiation, the catalase activities in livers of acatalasemic and normal mice and that in spleens of normal mice significantly decreased compared with no-irradiation control, and there were no differences between those catalase activities. The total glutathione content in acatalasemic mice was significantly higher than that in normal mice at 10 days after 6.0 Gy irradiation. These findings suggested that the radiosensitivity of acatalasemic mice in terms of whole body irradiation doesn’t significantly differ from that of normal mice, probably due to compensated sufficient contents of glutathione peroxidase and total glutathione in acatalasemic mice

Application of Polysaccharide-Based Chiral HPLC Columns for Separation of Nonenantiomeric Isomeric Mixtures of Organometallic Compounds

A series of polysaccharide-based chiral stationary phase (CSP) columns, Daicel Chiralpak IA, IB, and IC, were applied in the separation of the nonenantiomeric isomers of various organometallic compounds and were found to be highly effective in recognizing isomers of minor structural differences. The CSP columns have succeeded to separate the double-bond regioisomers in bridged (η5-formylcyclopentadienyl)manganese(I) dicarbonyl complexes 1a/1b, the structural isomers of methylbutenylferrocene derivatives in 2a/2b and 3a/3b, and the geometrical isomers of the (2-methyl-2-butenyl)ferrocenes in (Z)/(E)-3b. Due to the close similarity of the isomeric compounds in these mixtures, separations of the components are extremely difficult and could not be attained by conventional methods such as silica gel column chromatography, silica gel HPLC, recrystallization, distillation/sublimation, etc. Clearly, the polysaccharide-based CSP columns have unique advantages in separation/purification technology, and this study has shown potential usefulness of the CSP columns in separation of not only enantiomeric but also nonenantiomeric mixtures