• Korean Journal of Pharmacognosy
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• v.32 no.2 s.125
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• pp.116-120
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• 2001

In order to determine the content of 5-hydroxymethyl-2-furaldehyde (5-HMF) in the Rehmanniae Radix Preparata, 5-HMF was isolated from the EtOAc fraction of the Rehmanniae Radix Preparata samples and identified by spectroscopic and physicochemical evidences. Twenty one samples prepared on the basis of increasing number of stewing times with wine were analyzed by HPLC. From this analysis, it was revealed that the samples processed under one to nine times of stewing showed increasing pattern in 5-HMF contents. And the samples processed under 9 to 18 times of stewing showed 0.53-0.74% in 5-HMF contents. However, for those samples processed more than 19 times, 5-HMF content profile showed decreasing pattern.

• Korean Journal of Pharmacognosy
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• v.31 no.3
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• pp.340-344
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• 2000

Lonicerae Flos, the flower of Lonicera japonica Thunb., has been used as a diuretic, stomachic, antipyretic, analgesic and anti-inflammatory agent in Korea. In order to evaluate the quality of Lonicerae Flos, the method of isolation and quantitative determination of luteolin $7-O-{\beta}-D-glucoside$ as a reference standard compound has been developed. Different specimens of Lonicerae Flos were collected from twenty Korean markets and were analyzed with HPLC using the mobile phase of MeOH-4.5% acetic acid solution (16.5:83.5). The average content of luteolin $7-O-{\beta}-D-glucoside$ from Lonicerae Flos in Korean markets was $0.43{\pm}0.34%$.

• Korean Journal of Pharmacognosy
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• v.31 no.3
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• pp.335-339
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• 2000

Polygoni Multiflori Radix, the root of Polygonum multiflorum Thunb., has been used as a tonic, and in the inflammation and constipation in Korea. In order to evaluate the quality of Polygoni Multiflori Radix, the method of isolation and quantitative determination of emodin as a reference standard compound has been developed. Different specimens of Polygoni Multiflori Radix were collected from twenty Korean markets and were analyzed with HPLC using the mobile phase of MeOH-water (64:36). The average content of emodin from Polygoni Multiflori Radix in Korean markets was 0.021%.

• Journal of Life Science
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• v.21 no.4
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• pp.610-612
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• 2011

We developed a spectrophotometric assay for the quantitative determination of chlorogenic acid based on the formation of green pigment at $50^{\circ}C$ under glycine and alkaline conditions in 96-well plates. The formation of green pigment was linear with a series of chlorogenic acid concentration (0-$300\;{\mu}M$). Using this method, the content of chlorogenic acid (12.42 mg/g dry weight) in the leaves of blueberry was quantified. This method is high-throughput, cost-effective, rapid, and easy to perform.

• Mass Spectrometry Letters
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• v.15 no.3
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• pp.149-157
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• 2024

The objective of the present study was to validate the analytical procedure for the quantitative determination of four trace metals (As, Cd, Pb, and Hg) in extracted fish lipids using Inductively Coupled Plasma-Mass Spectrometry, ICP-MS. The extracted lipids using Bligh and Dyer method were digested by means of microwave-assisted acid digestion and introduced into an optimized ICP-MS instrument. The validation of the analytical method was carried out in accordance with the international standards and guidelines outlined in the European Pharmacopeia (2022), which included specificity, selectivity, linearity, limit of detection, limit of quantification, precision, and accuracy. The linearity ranges of the calibration curves were R² > 0.999, while the relative standard deviation (%RSD) for precision was within 5%. All targeted trace metals have shown mean recoveries between 88.0%-114.9%. The obtained LOD and LOQ values for this analytical protocol indicated the ability to detect and quantify of As, Cd, Pb, and Hg at trace levels. The overall validation confirms the described analytical method was appropriate for routine analyses of As, Cd, Pb, and Hg in fish lipids.

• Journal of Embryo Transfer
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• v.24 no.3
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• pp.225-230
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• 2009

Sex-sorting of sperm is an assisted reproductive technology (ART) used by the livestock industry for the mass production of animals of a desired sex. The standard method for sorting sperm is the detection of DNA content differences between X and Y chromosome-bearing sperm by flow cytometry. However, this method has variable efficiency and therefore requires verification by a second method. We have developed a sex determination method based on quantitative real-time polymerase chain reaction (qPCR) of the porcine amelogenin (AMEL) gene. The AMEL gene is present on both the X and the Y chromosome, but the length and sequence of its noncoding regions differ between the X and Y chromosomes. By measuring the threshold cycle (Ct) of qPCR, we were able to calculate the relative frequency of X chromosome. Two sets of AMEL primers were used in these studies. One set (AME) targeted AMEL gene sequences present in both X and Y chromosome, but produced PCR products of different lengths for each chromosome. The other set (AXR) bound to AMEL gene sequences present on the X chromosome but absent esholthe Y-chromosome. Relative product levels were calculated by normalizing the AXR fluorescence to the AME fluorescence. The AMEL method accurately predicted the sex ratios of boar sperm, demonstrating that it has potential value as a sex determination method.

• Journal of the Korean Society of Tobacco Science
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• v.27 no.1 s.53
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• pp.107-114
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• 2005

The uncertainty of measurement in quantitative analysis of ammonia by continuous-flow analysis method was evaluated following internationally accepted guidelines. The sources of uncertainty associated with the analysis of ammonia were the weighing of sample, the preparation of extracting solution, the addition of extracting solution into the sample, the reproducibility of analysis and the determination of water content in tobacco, etc. In calculating uncertainties, Type A of uncertainty was evaluated by the statistical analysis of a series of observation, and Type B by the information based on supplier's catalogue and/or certificated of calibration. It was shown that the main source of uncertainty was caused by the volume measurement of 1 mL and 2 mL, the purity of ammonia reference material in the preparation of standard solution, the reproducibility of analysis and the determination of water content of tobacco. The uncertainty in the addition of extraction solution, the sample weighing, the volume measurement of 50 mL and 100 mL, and the calibration curve of standard solution contributed relatively little to the overall uncertainty. The expanded uncertainty of ammonia determination in burley tobacco at $95\%$ level of confidence was $0.00997\%$.

• Journal of Mechanical Science and Technology
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• v.18 no.6
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• pp.961-971
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• 2004

Methods for determination of the crack opening stress intensity factor ($K_{op}$) and for estimation of the effective stress intensity factor range ($\Delta{K}_{eff}$) are evaluated for crack growth test data of aluminum alloys. Three methods of determining $K_{op}$, visual measurement, ASTM offset compliance method, and the neural network method proposed by Kang and Song, and three methods of estimating $\Delta{K}_{eff}$, conventional, the 2/PIO and 2/PI methods proposed by Donald and Paris, are compared in a quantitative manner by using evaluation criteria. For all $K_{op}$ determination methods discussed, the 2/PI method of estimating $\Delta{K}_{eff}$ provides good results. The neural network method of determining $K_{op}$ provides good correlation of crack growth data. It is recommended to use 2/PI estimation with the neural $K_{op}$ determination method. The ASTM offset method used in conjunction with 2/PI estimation shows a possibility of successful application. It is desired to improve the ASTM method.

• Archives of Pharmacal Research
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• v.27 no.11
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• pp.1114-1119
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• 2004

This paper describes the quantitative determination of flavonoids, tannins and ellagic acid in the leaves from wild and cultivated variations of Rubus L. species (Rosaceae): raspberry (2 wild and 13 cultivars) and blackberry (3 wild and 3 cultivars). The content of flavonoids was analyzed using spectrophotometric (the Christ-M llers method) and HPLC analysis after acid hydrolysis. The content of tannins was determined by the weight method, with hide powder, described by German Pharmacopoeia 10 (DAB 10). Ellagic acid content was examined using the HPLC method after acid hydrolysis. Flavonoid content, determined using the Christ-Muller's method was higher for the blackberry leaves than for the raspberry leaves and varied between 0.46% and 1.05%. Quercetin and kaempferol were predominant in all samples analyzed using the HPLC method. The highest flavonoid content was found in the leaves of R. nessensis (1.06%); with results in all of the examined samples varying between 0.27% and 1.06%. The concentration of ellagic acid in all species was determined after acid hydrolysis and ranged from 2.06% to 6.89%. The leaves of raspberries are characterized by greater amounts of tannins (varying between 2.62% and 6.87%) than the leaves of other species. The results from this study indicate that the analyzed species are a rich source of flavonoids, ellagic acid and tannins, which may be used for the quality assessment of Rubus L. species leaves.

• Archives of Pharmacal Research
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• v.26 no.2
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• pp.114-119
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• 2003

A high performance liquid chromatographic (HPLC) method was developed for the qualitative and quantitative determination of benzophenanthridine alkaloids from the methanol extracts of Hylomecon hylomeconoides and H. vernale (Papaveraceae). Achiral and chiral methods were adapted for the separation of 6-methoxydihydrosanguinarine (1), 6-acetonyldihydrosanguinarine (2) and dihydrosanguinarine (3). The achiral reversed phase HPLC method made it possible the simultaneous separation and determination of 1, 2 and 3 within 20 min on ODS column using acetonitrile-phosphate buffer (50 mM, pH 7.0) (50 : 50, v/v). The separation and determination of 1 and 2 enantiomers was available using chiral columns. The same amount of (+) and (-)-enantiomers of 1 was found from the methanol extract of specimen, indicated that 1 could be the artifact produced by the reaction of sanguinarine with methanol. H. hylomeconoides showed higher level of 1 and 3 in compared with H. vernale, especially in root samples permitting the possibility of chemical discrimination between two species.