[Application of Three Dimensional Confocal Micro X-Ray Fluorescence Technology Based on Polycapillary X-Ray Lens in Analysis of Rock and Mineral Samples].

Confocal three dimensional (3D) micro X-ray fluorescence (XRF) spectrometer based on a polycapillary focusing X-ray lens (PFXRL) in the excitation channel and a polycapillary parallel X-ray lens (PPXRL) in the detection channel was developed. The PFXRL and PPXRL were placed in a confocal configuration. This was helpful in improving the signal-to-noise ratio of the XRF spectra, and accordingly lowered the detection limitation of the XRF technology. The confocal configuration ensured that only the XRF signal from the confocal micro-volume overlapped by the output focal spot of the PFXRL and the input focal spot of the PPXRL could be detected by the detector. Therefore, the point-to-point information of XRF for samples could be obtained non-destructively by moving the sample located at the confocal position. The magnitude of the gain in power density of the PFXRL was 10(3). This let the low power conventional X-ray source be used in this confocal XRF, and, accordingly, decreased the requirement of high power X-ray source for the confocal XRF based on polycapillary X-ray optics. In this paper, we used the confocal 3D micro X-ray fluorescence spectrometer to non-destructively analyzed mineral samples and to carry out a 3D point-to-point elemental mapping scanning, which demonstrated the capabilities of confocal 3D micro XRF technology for non-destructive analysis elements composition and distribution for mineral samples. For one mineral sample, the experimental results showed that the area with high density of element of iron had high density of copper. To some extent, this reflected the growth mechanisms of the mineral sample. The confocal 3D micro XRF technology has potential applications in such fields like the analysis identification of ore, jade, lithoid utensils, "gamble stone" and lithoid flooring.

Adjustable hollow-cone output x-ray beam from an ellipsoidal monocapillary with a pinhole and a beam stop.

A combined shading system (CSS) consisting of a beam stop and a pinhole is proposed to be used between an ellipsoidal monocapillary (EM) and a conventional laboratory x-ray source to obtain an adjustable hollow-cone output beam for different experiments with no need for changing the EM. The CSS can change the incident x-ray beam on the EM by adjusting the position of the beam stop and the pinhole, with the corresponding change of the output beam of the EM. In this study, the adjustable hollow-cone output x-ray beam of an 80-mm-long EM with a CSS was studied in detail with a laboratory Cu x-ray generator with a focal spot diameter of 50 µm. The adjustable range of the focal spot size of the EM was from 8.6 to 58.7 µm. The adjustable range of the gain of the focal spot of the EM was from 0 to 1350. The beam divergence of the hollow-cone output beam of the EM ranged from 6 to 16.75 mrad. The illumination angle of the hollow-cone output beam of the EM ranged from 0 to 5.95 mrad. In addition, the potential application of the proposed adjusting method in testing the performance of the EM is briefly discussed.

Identification of geometrical isomers and comparison of different isomeric samples of astaxanthin.

A high-performance liquid chromatographic (HPLC) analysis system for isomeric astaxanthin was developed. The separation system consisted of a C(30) column and an elution system of methanol/MTBE/water/dichloromethane (77:13:8:2, v/v/v/v). Using the combination of HPLC diode array detector and HPLC atmospheric pressure chemical ionization mass spectrometry, 11 geometrical isomers and 4 epoxides of astaxanthin were successfully identified. Referred to crystal, only isomerization with different degrees was found for solvent dissolving and iodine catalysis, while melting of astaxanthin caused isomerization, slight oxidation, and more noticeable polymerization confirmed by gel permeation chromatography. Chemical changes in isomeric samples all caused a decrease in UV content. The vibrational spectra (infrared and Raman) showed that epoxide was the only new functional group generated for melting. Changes of several key bands and formations of new bands were found in iodine catalysis and melting samples because of isomerization. Practical Application: Eleven geometrical isomers and 4 epoxides, which were normally generated for solvent dissolving, iodine catalysis, and melting of astaxanthin, have been identified by C(30) -HPLC-MS technology. Furthermore, different samples were measured by gel permeation chromatography, UV, infrared, and Raman, based on the analysis of messages, the effect of each processing was well understood.

1,3-Dimethyl 5-(4,4,5,5-tetra-methyl-1,3,2-dioxaborolan-2-yl)benzene-1,3-dicarboxyl-ate.

The title compound, C(16)H(21)BO(6), has has approximate C(2) symmetry, but no crystallographically imposed mol-ecular symmetry. In the crystal, mol-ecules are packed into parallel columns along the a axis. Short inter-molecular C-H⋯O contacts stabilize the crystal packing.