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1.
B. Venkateswara Reddy K. V. N. Suresh Reddy J. Sreeramulu G. V. Kanumula 《Chromatographia》2007,66(1-2):111-114
A rapid, specific reversed phase HPLC method has been developed for simultaneous determination of olanzapine and fluoxetine
in their formulations. Chromatographic separation of these two pharmaceuticals was carried out on an Inertsil C18 reversed phase column (150 mm × 4.6 mm, 5 μm) with a 40:30:30 (v/v/v) mixture of 9.5 mM sodium dihydrogen phosphate (pH adjusted to 6.8 ± 0.1 with triethylamine), acetonitrile and methanol as
mobile phase. The flow rate 1.2 mL min−1 and the analytes are monitored at 225 nm. Paroxetine was used as internal standard. The assay results were linear from 25
to 75 μg mL−1 for olanzapine (r
2 ≥ 0.995) and 100–300 μg mL−1 for fluoxetine (r
2 ≥ 0.995), showed intra- and inter-day precision less than 1.0%, and accuracy of 97.7–99.1% and 97.9–99.0%. LOQ was 0.005
and 0.001 μg mL−1 for olanzapine and fluoxetine, respectively. Separation was complete in less than 10 min. Validation of the method showed
it to be robust, precise, accurate and linear over the range of analysis. 相似文献
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Harshal P. Mungse Niharika Bhakuni Deependra Tripathi Om P. Sharma Bir Sain Om P. Khatri 《Journal of Physical Organic Chemistry》2014,27(12):944-951
Graphene oxide (GrO) prepared by the Hummers method was separated into three different fractions (GrO5000, GrO2000, and GrOres) on the basis of their dispersion stability in the water. Infrared, nuclear magnetic resonance, X‐ray photoelectron spectroscopy, and elemental analyses revealed that GrO5000 possesses a high degree of oxygen functionalities including phenolic, carboxylic, and ?OSO2H groups, compared with the other fractions. The GrO5000 was found to be a highly efficient and reusable solid catalyst for the esterification of various carboxylic acids with a variety of alcohols to furnish corresponding esters in high to excellent yields. The catalytic activity of the GrO5000 was attributed to the ability of highly polar GrO5000 scaffold to adsorb/attract reactants, where the acid functionalities of GrO5000 facilitated the esterification process efficiently. The chemical and structural features of GrO5000 were discussed to understand the improved catalytic activity compared with GrO2000 and conventional solid acid catalysts. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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Bishnu P. Biswal Sreeramulu Valligatla Mingchao Wang Tanmay Banerjee Nabil A. Saad Bala Murali Krishna Mariserla Naisa Chandrasekhar Daniel Becker Matthew Addicoat Irena Senkovska Reinhard Berger D. Narayana Rao Stefan Kaskel Xinliang Feng 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(21):6970-6974
Covalent organic frameworks (COFs) have garnered immense scientific interest among porous materials because of their structural tunability and diverse properties. However, the response of such materials toward laser‐induced nonlinear optical (NLO) applications is hardly understood and demands prompt attention. Three novel regioregular porphyrin (Por)‐based porous COFs—Por‐COF‐HH and its dual metalated congeners Por‐COF‐ZnCu and Por‐COF‐ZnNi—have been prepared and present excellent NLO properties. Notably, intensity‐dependent NLO switching behavior was observed for these Por‐COFs, which is highly desirable for optical switching and optical limiting devices. Moreover, the efficient π‐conjugation and charge‐transfer transition in ZnCu‐Por‐COF enabled a high nonlinear absorption coefficient (β=4470 cm/GW) and figure of merit (FOM=σ1/σo, 3565) value compared to other state‐of‐the‐art materials, including molecular porphyrins (β≈100–400 cm/GW), metal–organic frameworks (MOFs; β≈0.3–0.5 cm/GW), and graphene (β=900 cm/GW). 相似文献
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JPC – Journal of Planar Chromatography – Modern TLC - Recently, considerable numbers of poisoning cases have been reported owing to the ingestion of three structurally related... 相似文献
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We have measured the magnetic susceptibility (χ) and heat capacity (C
p) of β-Cu2−x
Zn
x
V2O7 (x = 0, 0.05, 0.1, 0.15, 0.2, 0.3, 2) in the temperature range 2–300 K. A one-dimensional alternating exchange Heisenberg antiferromagnetism
(HAF) is observed in all compositions with chains of infinite length. The intra-chain exchange remains uniform and decreases
marginally with dilution of the magnetic state. A cooperative ordering is seen in the magnetic chains for all Zn concentrations
(x ≤ 0.3). The temperature of occurrence of this transition decreases with increasing Zn concentration. Though the conventional
spin-wave theory has been used here to describe the properties of the ordered phase, the presence of some contributions like
the lattice heat capacity in C
p and the Curie-Weiss term in susceptibility introduces some uncertainties in the estimation of the proportions contributed
by the spin system. Therefore, the nature of the ordered phase could not be ascertained unambiguously. 相似文献
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Niharika Mohapatra 《Solid State Communications》2007,143(3):149-152
The compound, Ca3CoRhO6, containing magnetic Co-Rh chains intervened by Ca ions, has been known to be one of the few exhibiting ‘partially disordered antiferromagnetic structure (PDA)’ due to geometrical frustration. Here, we report the influence of partial replacement of Ca by Y on the magnetic anomalies by investigating the solid solution, Ca3−xY xCoRhO6, by bulk measurements. There are profound changes in the magnetic behavior, the most notable one being that the features attributable to spin-chain magnetism and PDA structure get suppressed dramatically by a small replacement of Ca by Y (x<0.3), despite the fact that the magnetic chain is not disrupted. This finding suggests that this compound is on the verge of PDA-structural-instability. 相似文献
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