Home About us Contact
|
Home About us Contact | ||
|
|
||
Potassium Dihydrogen Phosphate (potassium + dihydrogen_phosphate)
Selected AbstractsPowder second harmonic generation measurement and thermal decomposition mechanisms of a new organometallic compound [(18C6)Li][Cd(SCN)3]CRYSTAL RESEARCH AND TECHNOLOGY, Issue 9 2009J. J. Zhang Abstract Single crystals of a novel nonlinear optical organometallic compound CLTC, ([(18C6)Li][Cd(SCN)3]), were grown from aqueous solutions via evaporation technique and characterized by IR spectroscopy, thermal gravimetric analysis and X-ray single-crystal diffraction. By X-ray single-crystal structural analysis it is revealed that the compound crystallized in a noncentrosymmetric space group Cmc21 of orthorhombic system with cell parameter a = 14.767(3) Å, b = 15.454(3) Å, c = 10.644(2) Å, V = 2429.0(8) Å3 and Z = 4. The thermal stability and thermal decomposition of CLTC crystal were investigated by means of thermogravimetry and differential thermal analysis. The second harmonic generation (SHG) efficiency was measured using the Kurtz and Perry powder technique. It was shown that the value of the SHG efficiency of CLCT powder was about 2 times higher than that of potassium dihydrogen phosphate (KDP). (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] The combined effects of supersaturation and Ba2+ on the batch cooling crystallization of potassium dihydrogen phosphateCRYSTAL RESEARCH AND TECHNOLOGY, Issue 6 2008Guozong Zheng Abstract The combined effects of supersaturation and Ba2+ on potassium dihydrogen phosphate (KDP) were investigated in batch cooling suspension crystallization. Growth size, morphology, and impurity Ba2+ adsorbed in the KDP crystals were measured with changing Ba2+ concentration and supersaturation. Significant changes in shapes and volume of the grown crystals have been observed. The results further confirmed that the size and shape of crystals were greatly determined by supersaturation. Ba2+ ions significantly modified the growth habit of KDP crystals. The concentration of Ba2+ ions adsorbed in the crystals increases with the increasing Ba2+ ions in the solutions and supersaturation. The foggy phenomena caused by the addition of Ba to the KDP solution were also described. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] HPLC for stress-free screening of potential prostate cancer marker catechol estrogens in urine using a diamond-electrode electrochemical and a fluorescence detectorJOURNAL OF SEPARATION SCIENCE, JSS, Issue 14 2007Masatoki Katayama Abstract Improvement of the sensitivity and specificity of a simultaneous stress-free screening method for catechol estrogens as a potential prostate cancer marker in urine has been accomplished by HPLC with a diamond-electrode electrochemical detector and a fluorescence detector. Since taking urine samples generates less stress (or pain) than the drawing of blood, the method can readily be applied to almost any patient, and will also assist in improving the sensitivity and specificity of the prostatic specific antigen test. Catechol estrogens (2-hydroxyestrone, 4-hydroxyestrone, 2-methoxyestrone, 2-hydroxyestradiol, 4-hydroxyestradiol, 2-methoxyestradiol, and 2-hydroxyestriol) and estrogens (estrone, estradiol, estriol) were separated on an Inertsil ODS-II column with acetonitrile,potassium dihydrogen phosphate (pH 3.0). The diamond-electrode electrochemical detector used had the great advantage of being a maintenance-free system, and could sequentially analyze hundreds of samples. Fluorescence detection improved the sensitivity 10,500 times (e. g., the LOD of 2-hydroxyestriol was improved 250 times) compared to previous electrochemical detection reports, and dual detection improved peak identification in the urine samples. The proposed method was applied to the simultaneous determination of catechol estrogens in spiked urine in a preliminary study on estrogens and PSA values in biopsy and prostate cancer patients. [source] Development and validation of a stereoselective HPLC method for the determination of the in vitro transport of nateglinide enantiomers in rat intestineJOURNAL OF SEPARATION SCIENCE, JSS, Issue 12 2007Srinivas Maddi Abstract A simple stereoselective high performance liquid chromatographic method was developed for the determination of the in vitro transport of the enantiomers of nateglinide (N -(trans -4-isopropylcyclohexyl-carbonyl)-phenylalanine) in the rat intestine using a Chiralcel OJ-RH column (150×4.0 mm, 5 ,m). The effects of the mobile phase composition, pH, the flow rate, and the temperature on the chromatographic separation were investigated. The enantioseparation was achieved at 33°C using a mobile phase containing 100 mM potassium dihydrogen phosphate, pH 2.5, and ACN (32:68 v/v) delivered at a flow rate of 1 mL/min. The analytes were monitored at 210 nm and linearity (r >0.99) was obtained for a concentration range of 0.5,50 ,g/mL. The LOD and LOQ were 0.2 and 0.5 ,g/mL for the R -enantiomer and 0.2 and 0.8 ,g/mL for the S -enantiomer, respectively. Both, the intra- and interday accuracy and precision of the calibration curves were determined. The method was successfully applied to estimate the in vitro passage of the enantiomers and the racemate of nateglinide in duodenum, jejunum, and ileum of rats. Generally, higher concentrations of nateglinide and the S -enantiomer were observed when the racemate was administered compared to administration of the individual enantiomers of nateglinide. [source] Hydrogen-bonded network in the trichloroacetate salts of 2-amino-5-chloropyridinium and 2-methyl-5-nitroanilinium monohydrateACTA CRYSTALLOGRAPHICA SECTION C, Issue 7 2009Jan Janczak In the crystal structures of 2-amino-5-chloropyridinium trichloroacetate, C5H6ClN2+·C2Cl3O2,, (I), and 2-methyl-5-nitroanilinium trichloroacetate monohydrate, C7H9N2O2+·C2Cl3O2,·H2O, (II), the protonated planar 2-amino-5-chloropyridinium [in (I)] and 2-methyl-5-nitroanilinium [in (II)] cations interact with the oppositely charged trichloroacetate anions to form hydrogen-bonded one-dimensional chains in (I) and, together with water molecules, a three-dimensional network in (II). The crystals of (I) exhibit nonlinear optical properties. The second harmonic generation efficiency in relation to potassium dihydrogen phosphate is 0.77. This work demonstrates the usefulness of trichloroacetic acid in crystal engineering for obtaining new materials for nonlinear optics. [source] HPLC-fluorescence assay for measuring mosapride in small volumes of rat plasmaBIOMEDICAL CHROMATOGRAPHY, Issue 3 2010Ching-Ling Cheng Abstract A simple and sensitive HPLC-fluorescence assay was developed for the determination of a gastroprokinetic agent mosapride in small volumes of rat plasma. Samples (50 ,L) were treated with 200 ,L of the internal standard solution (cisapride, 0.1 ,g/mL in acetonitrile). Chromatographic separation was achieved on a C18 column by gradient elution with the mobile phase of acetonitrile-water containing 20 mM potassium dihydrogen phosphate, at a flow rate of 1 mL/min. Fluorescence was measured with excitation and emission set at 315 and 354 nm, respectively. The retention time was about 16 min for cisapride and 20 min for mosapride. No endogenous substances were found to interfere. The calibration curve was linear from 0.015 to 10 ,g/mL. The lower limit of quantification was 0.015 ,g/mL. The intra- and inter-day precision expressed as relative standard deviation did not exceed 7.7%, and the accuracy was within 4.7% deviation of the nominal concentration. The method was used successfully to investigate the disposition kinetics of mosapride in rats. Copyright © 2009 John Wiley & Sons, Ltd. [source] | ||||||||||