• Korean Journal of Pharmacognosy
• /
• v.16 no.3
• /
• pp.175-179
• /
• 1985

The optimal condition for the determination of saikosaponin a and d, the major pharmacologically active saponins of the roots of Bupleurum falcatum, was studied with the conversion of these saponins into diene saponins $(saikosaponin\;b_1\;and\;b_2)$. The complete separation and quantitative analysis of these saponins were performed by the method of high performance liquid chromatography using $NH_2$ column. The conversion of saikosaponin a and d into diene saponins under gastric pH was calculated. Thirty-three percent of saikosaponin a was converted to saikosaponin $b_1$ and 63 percent of saikosaponin d was converted to saikosaponin $b_2$.

• Mass Spectrometry Letters
• /
• v.2 no.1
• /
• pp.16-19
• /
• 2011

Oxidation products of ceftiofur were formed in hydrogen peroxide solution. The structures of the ceftiofur oxidation products were characterized by high-performance liquid chromatography/electrospray ionization/tandem mass spectrometry (HPLC/ESI/MS/MS). The products were identified as compounds oxidized at the sulfur of a cephem ring. For further analysis, experiments were performed using $O^{18}$-labeled hydrogen peroxide. In addition, density-functional calculations were carried out for six possible oxidation products to support the experimental results.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.29 no.2
• /
• pp.181-187
• /
• 2000

The contents of organic acid in Korean apple juice were analyzed by HPLC using YMC-peak ODS-AQ column and enzymatic assay. Model apple juices were prepared at the laboratory and commercial apple juices were purchased from the market. Individual organic acid contents were as follows: DL-malic acid 62~402mg%, L-malic acid 48~360mg%, citric acid 1.81~15.74mg%, fumaric acid nd~0.50mg%. Together, these tests gave useful information about the quality and authenticity of a particular apple juice smaple. The presence of D-malic acid was a clear indication of adulteration because this isomer did not occur naturally. Fumaric acid and citric acid levels above trace amounts were also inconsistent with pure apple juice.

• Korean Journal of Veterinary Research
• /
• v.57 no.4
• /
• pp.223-226
• /
• 2017

This study was undertaken to develop new analytical methods for assessment of anticoccidials. High-performance liquid chromatography (HPLC) was found to be a fast, reliable, and practical method. The anticoccidials used in this experiment were toltrazuril and diclazuril, and the analysis factors were specificity, linearity, accuracy, repeatability, and intermediate precision. The linearity of each anticoccidial was better than 0.99, and the accuracies were 99.5% and 99.1% with relative SD of 0.5 and 0.4, respectively. To assess whether the developed HPLC method could be effectively applied, toltrazuril and diclazuril post-market veterinary products (five products) that are currently sold were tested. The results revealed no non-compliant items and the method was applied successfully. Therefore, the newly developed HPLC method for anticoccidial assessment described in this study may be useful as a reference method in the Korean Standards of Veterinary Pharmaceuticals for the analysis of toltrazuril and diclazuril.

• Food Science of Animal Resources
• /
• v.43 no.5
• /
• pp.914-937
• /
• 2023

The objective of this study was to establish a multi-residue quantitative method for the analysis of anthelmintic and antiprotozoal drugs in various livestock products (beef, pork, and chicken) using ultra-high-performance liquid chromatography-tandem mass spectrometry. Each compound performed validation at three different levels i.e., 0.5, 1, and 2× the maximum residue limit according to the CODEX guidelines (CAC/GL 71-2009). This study was conducted according to the modified quick, easy, cheap, effective, rugged, and safe procedure. The matrix-matched calibrations gave correlation coefficients >0.98, and the obtained recoveries were in the range of 60.2%-119.9%, with coefficients of variation ≤32.0%. Furthermore, the detection and quantification limits of the method were in the ranges of 0.03-3.2 and 0.1-9.7 ㎍/kg, respectively. Moreover, a survey of residual anthelmintic and antiprotozoal drugs was also carried out in 30 samples of beef, pork, and chicken collected in Korea. Toltrazuril sulfone was detected in all three samples. Thus, our results indicated that the developed method is suitable for determining the anthelmintic and antiprotozoal drug contents in livestock products.

• Advances in environmental research
• /
• v.2 no.3
• /
• pp.179-202
• /
• 2013

Bisphenol A and other alkylphenols are widely used in plastic and other industrial consumer products. Release of these compounds into the aquatic environment during their manufacture, use and disposal has been a great scientific and public concern due to their toxicity at high concentrations and endocrine disrupting effects at low concentration on aquatic wildlife and human beings. This paper reviews the published data and researches on the environmental occurrence, distribution, health effects and analytical techniques of bisphenol A and alkylphenols. The aim is to provide an overview of the current understanding about bisphenol A and alkylphenols in the environment and the difficulties faced today in order to establish standard and systematic environmental analysis and assessment process for these endocrine disruptor compounds.

• Applied Biological Chemistry
• /
• v.41 no.8
• /
• pp.595-599
• /
• 1998

An analytical method was developed to determine tricyclazole residues in rice grain, straw, and soil using high-performance liquid chromatography (HPLC) with ultraviolet absorption detection. Tricyclazole was extracted with methanol from moist rice grain, straw, and soil samples. n-Hexane washing was employed to remove nonpolar co-extractives during liquid-liquid partition. Tricyclazole was then extracted with dichloromethane from alkaline aqueous phase, while acidic interferences remained in the phase. Dichloromethane extract was further purified by silica gel column chromatography prior to HPLC determination. Reverse-phase HPLC using an octadecylsilyl column was successfully applied to separate and quantitate the tricyclazole residue in sample extracts monitored at ${\lambda}_{max}$ 225nm. Recoveries from fortified samples averaged $95.5{\pm}3.0%\;(n=6),\;87.5{\pm}20.%\;(n=6),\;and\;84.3{\pm}2.8%$ (n=12) for rice grain, straw, and soil, respectively. Detection limit of the method was 0.02 mg/kg for rice grain and soil samples while 0.05 mg/kg for rice straw samples. The proposed method was reproducible and sensitive enough to evaluate the safety of tricyclazole residues in rice grain, straw, and soil.

• YAKHAK HOEJI
• /
• v.23 no.3_4
• /
• pp.181-186
• /
• 1979

A high performance liquid chromatograpic procedure is described for determining ginseng saponins such as ginsenoside-Rb1, -Rb2, -Rc, -Rd, -Re, -Rf, -Rg1, and-Rg2. Ginseng saponins extracted with 90% methanol and water-saturated butanol were compared with pure standard ginsenosides. The resolution of the saponins was satisfactory and detection limit for each saponin was about 5.mu.g. Separation of the saponins was accomplished using a .mu. Bondapak carbohydrate analysis column, mobile phase of acetonitrile-water-butanol (80:20:15) and differential refractive index (RI) detector. The reproducibility and the recovery were also studied. This method was applied for determining the saponin contents of several parts of leaf, fresh ginseng, white ginseng, and red ginseng.

• Analytical Science and Technology
• /
• v.15 no.3
• /
• pp.248-255
• /
• 2002

The contents of ${\alpha}$-, ${\beta}$-, ${\gamma}$-, and $\delta$-tocopherols in sesame oils were determined by high performance liquid chromatography with UV detection. ${\alpha}$-Tocopherol contents ranged from 10.28 to 19.79 mg/g oil, ${\beta}$-tocopherol contents from 8.22 to 20.10 mg/g. However, both ${\gamma}$- and $\delta$-tocopherol were less than 1.49 mg/g or not detected. ${\gamma}$-Tocopherol was not detected from both unroasted white and black sesame seed oils. Significantly higher level of tocopherol in sesame oil than other oils is an evidence of the reason why it is highly stable and prevents oxidation. The tocopherol composition for twenty sesame oils was classified by using principal component analysis.

• Korean Journal of Pharmacognosy
• /
• v.50 no.2
• /
• pp.133-140
• /
• 2019

In our previous study, we found uracil, adenosine, protocatechuic acid, syringin (eleutheroside B) and scoparone (6, 7-dimethoxycoumarin) in the Oplopanax elatus Nakai Stem. High-performance liquid chromatography (HPLC) -UV was used to quality and quantify the internal marker compounds in the O. elatus extract after validation of method with linearity, limit of detection (LOD), limit of quantitation (LOQ), accuracy and precision. The specificity assessment visually confirmed that the substance was detected without the introduction of other substances. The established method showed high linearity of the calibration curve and coefficient of correlation ($R^2$) of over the 0.999. HPLC was reported as five standard compounds equivalent using the following linear equation based on the calibration curve. The accuracy of measurement was 84.34 ~ 119.74% and the relative standard deviation (RSD) value was 0.28 ~ 1.60%. In addition, our established method showed high repeatability. The RSD value was 1.10 ~ 6.81%. So, we found the amount of the internal marker compounds in the O. elatus extract. These results demonstrated that can be used to quality evaluation of the O. elatus.