Home About us Contact
|
Home About us Contact | ||
|
|
||
Reversed-phase High-performance Liquid Chromatographic Method (reversed-phase + high-performance_liquid_chromatographic_method)
Selected AbstractsA reversed-phase high-performance liquid chromatographic method for the determination of aloesin, aloeresin a and anthraquinone in Aloe feroxPHYTOCHEMICAL ANALYSIS, Issue 2 2008Michael Zahn Abstract A reversed-phase HPLC method for the quantification of aloesin, aloeresin a and anthraquinone (as barbaloin) in Aloe ferox Miller and aloe-related products has been developed and validated. The method utilized a C18 column with a water,methanol gradient and UV detection at 297 nm. The method validation included linearity, accuracy, precision, limit of detection, limit of quantitation, specificity and standard solution stability. The method showed good linearity (r > 0.99 for all components) and recovery (>85% for all components). The detection and quantitation limits for barbaloin were determined to be 0.02 and 0.1 ppm at signal-to-noise ratios of approximately 3:1 and 10:1, respectively. Copyright © 2007 John Wiley & Sons, Ltd. [source] Simultaneous quantification of eudesmanolides and thymol derivatives from tissues of Inula helenium and I. royleana by reversed-phase high-performance liquid ChromatographyPHYTOCHEMICAL ANALYSIS, Issue 3 2006Anna Stojakowska Abstract A simple and rapid isocratic reversed-phase high-performance liquid chromatographic method for the quantification of alantolactone/isoalantolactone and three thymol derivatives in roots and root cultures of Inula helenium and I. royleana has been developed. The method could be applied to screen raw materials in search for highly productive plants and in vitro cultures. Copyright © 2006 John Wiley & Sons, Ltd. [source] Optimization and validation of RP-HPLC-UV method with solid-phase extraction for determination of buparvaquone in human and rabbit plasma: application to pharmacokinetic studyBIOMEDICAL CHROMATOGRAPHY, Issue 5 2008Gantala Venkatesh Abstract A simple, sensitive and specific reversed-phase high-performance liquid chromatographic method with UV detection at 251 nm was developed for quantitation of buparvaquone (BPQ) in human and rabbit plasma. The method utilizes 250 µL of plasma and sample preparation involves protein precipitation followed by solid-phase extraction. The method was validated on a C18 column with mobile phase consisting of ammonium acetate buffer (0.02 m, pH 3.0) and acetonitrile in the ratio of 18:82 (v/v) at a flow rate of 1.1 mL/min. The calibration curves were linear (correlation coefficient ,0.998) in the selected range. The method is specific and sensitive with limit of quantitation of 50 ng/mL for BPQ. The validated method was found to be accurate and precise in the working calibration range. Stability studies were carried out at different storage conditions and BPQ was found to be stable. Partial validation studies were carried out using rabbit plasma and intra- and inter-day precision and accuracy were within 7%. This method is simple, reliable and can be routinely used for preclinical pharmacokinetic studies for BPQ. Copyright © 2007 John Wiley & Sons, Ltd. [source] Simple and rapid high-performance liquid chromatographic method for endogenous , -tocopherol determination in human plasmaBIOMEDICAL CHROMATOGRAPHY, Issue 8 2006Katthaleeya Nirungsan Abstract A simple and rapid reversed-phase high-performance liquid chromatographic method was developed and validated for the determination of endogenous , -tocopherol in human plasma. Following addition of , -tocopheryl acetate as the internal standard, the plasma was deproteinized using acetonitrile and isopropanol mixture prior to HPLC analysis. Methanol was used as the mobile phase and the effluent was quantitated at 292 nm. By this developed method, the concentrations of , -tocopherol were linearly related to their responses in the range of 0.8,30 µg/mL. The relative standard deviations intra-day and inter-day for , -tocopherol in plasma were less than 10%. The percentage of bias was within ±4%, which confirmed the accuracy of the method. The method has been successfully applied for determining endogenous , -tocopherol in healthy Thai male volunteers. Copyright © 2005 John Wiley & Sons, Ltd. [source] Analysis of neuroactive amino acids from microdialysate samples by fluorescence detection using a modification of the 6-aminoquinolyl- N -hydroxysuccinimidyl carbamate methodBIOMEDICAL CHROMATOGRAPHY, Issue 10 2005M. Teresa Oreiro-García Abstract A sensitive and rapid reversed-phase high-performance liquid chromatographic method using pre-column derivatization with 6-aminoquinolyl- N -hydroxysuccinimidyl carbamate (AQC) and fluorescence detection is reported. By directly derivatizing microdialysate samples with AQC, an automatic and rapid simultaneous measurement of aspartate, serine, glutamate, glycine and histidine was developed. Excellent linearity (r2 , 0.998) was achieved for the standard mixture used for the validation experiments. Within-day and between-day precision was less than 6.2%, and the accuracy ranged from 95 to 105.2% in standards. This method is suitable for single run analysis of a high number of small volume microdialysate samples from rat hippocampus. Amino acids from microdialysate samples were quantified with RSD for reproducibility below 2%, and at approximately 0.1% for retention time. Copyright © 2005 John Wiley & Sons, Ltd. [source] Rapid high-performance liquid chromatographic measurement of buspirone in human plasma after overdoseBIOMEDICAL CHROMATOGRAPHY, Issue 9 2004F. Péhourcq Abstract For toxicological purposes, a rapid reversed-phase high-performance liquid chromatographic method was developed for the determination of the anxiolytic drug, buspirone, in human plasma. A liquid,liquid procedure was used to extract this compound from plasma in the presence of an internal standard, quinupramine. The analysis was performed on a Spherisorb® S5 C8 analytical column with UV detection at 240 nm. No endogenous compounds were found to interfere. A linear response was observed over the concentration range 5,100 ng/mL. A good accuracy (bias ,7.9%) was achieved for all quality controls, with intra-day and inter-day variation coef,cients equal or less than 7.6%. The limit of quanti,cation was 5 ng/mL. Stability of buspirone in plasma stored at different temperatures was checked. This rapid method (run time <12 min) was used to manage an acute poisoning involving buspirone. Copyright © 2004 John Wiley & Sons, Ltd. [source] | ||||||||||