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Densitometric Method (densitometric + method)
Selected AbstractsA rapid densitometric method for simultaneous quantification of gallic acid and ellagic acid in herbal raw materials using HPTLCJOURNAL OF SEPARATION SCIENCE, JSS, Issue 6 2005Milind Bagul Abstract Gallic acid and ellagic acid are two widely occurring phenolic compounds of plant origin, to which many biological activities including anticancer and antiviral activity have been attributed. A simple HPTLC method has been developed for the simultaneous quantification of gallic acid and ellagic acid. The method was validated for precision, repeatability, and accuracy. Instrumental precision was found to be 0.083 and 0.78, and the repeatability of the method was found to be 1.07 and 1.50 (% CV) for gallic acid and ellagic acid, respectively. The accuracy of the method was checked by a recovery study conducted at two different levels and the average percentage recovery was found to be 101.02% for gallic acid and 102.42% for ellagic acid. The above method was used for the quantification of gallic acid and ellagic acid content in seeds of Abrus precatorius Linn., whole plant of Phyllanthus maderaspatensis Linn., and flowers of Nymphaea alba Linn. The proposed HPTLC method for the simultaneous quantification of gallic acid and ellagic acid was found to be simple, precise, specific, sensitive, and accurate and can be used for routine quality control of herbal raw materials and for the quantification of these compounds in plant materials. [source] Application of Scion image software to the simultaneous determination of curcuminoids in turmeric (Curcuma longa)PHYTOCHEMICAL ANALYSIS, Issue 1 2009Uthai Sotanaphun Abstract Introduction Curcumin, desmethoxycurcumin and bisdesmethoxycurcumin are bioactive constituents of turmeric (Curcuma longa). Owing to their different potency, quality control of turmeric based on the content of each curcuminoid is more reliable than that based on total curcuminoids. However, to perform such an assay, high-cost instrument is needed. Objective To develop a simple and low-cost method for the simultaneous quantification of three curcuminoids in turmeric using TLC and the public-domain software Scion Image. Methodology The image of a TLC chromatogram of turmeric extract was recorded using a digital scanner. The density of the TLC spot of each curcuminoid was analysed by the Scion Image software. The density value was transformed to concentration by comparison with the calibration curve of standard curcuminoids developed on the same TLC plate. Results The polynomial regression data for all curcuminoids showed good linear relationship with R2 > 0.99 in the concentration range of 0.375,6 µg/spot. The limits of detection and quantitation were 43,73 and 143,242 ng/spot, respectively. The method gave adequate precision, accuracy and recovery. The contents of each curcuminoid determined using this method were not significantly different from those determined using the TLC densitometric method. Conclusion TLC image analysis using Scion Image is shown to be a reliable method for the simultaneous analysis of the content of each curcuminoid in turmeric. Copyright © 2008 John Wiley & Sons, Ltd. [source] Simultaneous determination of cinnamaldehyde, eugenol and piperine by HPTLC densitometric methodPHYTOCHEMICAL ANALYSIS, Issue 2 2008C. L. Gopu Abstract An HPTLC densitometric method for the simultaneous determination of cinnamaldehyde and eugenol as well as trace amounts of piperine in pepper-contaminated cinnamon was developed. The applicability of the method was tested with cinnamon bark powder adulterated with pepper powder, cinnamon oil, clove powder, clove oil and a commercial preparation containing cinnamaldehyde and eugenol. The method was validated for specificity, precision, accuracy and robustness. The method was found to be precise for different concentrations of cinnamaldehyde, eugenol and piperine. The accuracy of the method was checked by conducting a recovery study at three different levels. The linearity was found to be in the ranges 52.54,735.56, 533.2,8531.2 and 50,300 ng/spot, respectively, with correlation coefficients of 0.9985 ± 0.04, 0.9982 ± 0.06 and 0.9937 ± 0.11 for cinnamaldehyde, eugenol and piperine. Copyright © 2007 John Wiley & Sons, Ltd. [source] Digital X-ray radiogrammetry: a new appendicular bone densitometric method with high precisionCLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 5 2000J. T. Jørgensen The precision of any given method for measurement of bone mineral density (BMD) is important in relation to the interpretation of repeated measurements over time, e.g. to monitor the course of suspected osteoporosis or follow the effect of therapy. In the present study a new bone densitometer using the digital X-ray radiogrammetry (DXR) method (Pronosco X-posure SystemÔ) is investigated with respect to its short-term precision. The study was carried out on two groups of females, one consisting of 20 women between the ages of 30 and 40, and the other of 20 post-menopausal women above the age of 64. The mean age of the premenopausal women was 35·2 years and the mean DXR BMD was 0·578 g cm,2. The mean age of the post-menopausal women was 68·2 years and the mean DXR BMD was 0·489 g cm,2. The short-term precision of the two groups was evaluated using the coefficient of variation (CV%) and corresponding 90% confidence intervals. The coefficient of variation in the premenopausal group was 0·68% with a 90% confidence interval of 0·57%,0·83%. The coefficient of variation in the postmenopausal group was 0·61% with a 90% confidence interval of 0·52,0·75%. It can be concluded from the present study that the short-term in vivo precision error of the DXR method is low in both pre- and post-menopausal women. When the results of the study are compared to data reported in the literature, the performance of the DXR method seems to be at least equivalent with peripheral DXA. [source] | ||||||||||