• Korean Journal of Food Science and Technology
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• v.17 no.4
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• pp.295-303
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• 1985

Aflatoxin $B_1$, $B_2$, $G_1$, and $G_2$were quantitatively detected by the high pressure liquid chromatography on a Micropak-CN column, with Hexane-THF-IPA-water, using a Lichrosorbpacked flowceil in the fluorometric detector. Under those conditions, the minimum detectable amount of aflatoxin $B_1$ was 0.2 ng. HPLC was used in determining amount of aflatoxins in the commercially manufactured soybean food and home-made Meju. Aflatoxin producing abilities of strains used in the industrially fermented soybean food were also studied with the HPLC technique. Although aflatoxin-like substances were detected in a few samples on TLC, they were not identified with the HPLC retention times of standard aflatoxins. The commercial fungal strains used in Korea had no aflatoxin producing abilities.

• Journal of Food Hygiene and Safety
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• v.3 no.4
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• pp.203-209
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• 1988

This study was performed to develop the simple and rapid determination method of preservatives in Yogurt and Soybean.sauce. 1. The analytical method by HPLC system was as follow: The sample was diluted, centrifuged, filtered, if necessary, and analyzed by HPLC system with UV detector. 2. The analytical method by GLC system was as follow: The sample was extracted directly with ether, added cone. sulfuric acid to destroy emulsion and analyzed by the GLC system with FID. 3. The recovery rates of preservatives by the above methods were higher than 99.0 %. 4. Total running time for the above methods was less than 50 minutes. Especially, the running time for dilution method by HPLC system was one-third of that for GLC method.

• Biomedical Science Letters
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• v.3 no.1
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• pp.29-35
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• 1997

Cardiovascular disease has been the leading cause of death among patients with chronic renal failure. Many reports have been described that homocysteine is one of the independent risk factor to the occulsive vascular disease. In this study, HPLC/FLD (high performance liquid chromatography-fluorescence detector) technique was used to measure homocysteine level in patients with chronic renal failure and normal control group. The detection limit and recovery of total plasma homocysteine using HPLC/FLD were 98.6$\pm$5.8% and 0.2 nmol/ml, respectively. The linearity of this method was established in concentration range of 2~50 nmol/ml (correlation coefficient=0.9997). The concentrations of total plasma homocysteine were 6.81$\pm$1.54 nmol/ml and 27.28$\pm$14.94 nmol/ml in normal control (n=20) and patient group (n=90), respectively (p<0.05). In this study, the HPLC/FLD method showed high sensitivity and reproducibility for a routine clinical laboratory testing. Moreover determination of homocysteine level in plasma might be useful for a biochemical marker for predicting the cardiovascular diseases and for monitoring of therapeutic effect of lowering homocysteine in patients with chronic renal failure.

• YAKHAK HOEJI
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• v.46 no.6
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• pp.392-397
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• 2002

A simple and sensitive high performance liquid chromatographic method to quantitate ursodeoxycholic acid in crude drug pharmaceuticals was investigated. Ursodeoxycholic acid react with 2-bromoacetyl-6-methoxynaphthalene (Br-AMN) in the presence of triethylamine to form highly fluorescent derivative. The derivatization procedure was performed at 7$0^{\circ}C$ and completed within 30 min. The optimal wavelength of the fluorescence detector are λ$_{ex}$=300 nm and λ$_{em}$ = 460 nm. The LOD of the ursodeoxycholic acid was 25 ng/mι based on the S/N =3, and the LOQ was 80 ng/mι based on S/N = 10. Crude drug pharmaceuticals pretreated by solid phase extraction (Sep-pak $C_{18}$ cartridge) which were shown very good separation and recovery values for the compound.d.

• YAKHAK HOEJI
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• v.31 no.2
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• pp.105-111
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• 1987

A high performance liquid chromatographic method was developed for the simultaneous determination of free and glycine conjugated bile acids. Free and glycine conjugated bile acids were extracted from bear gall bladder by methanol and from serum using a Sep-pak $C_{18}$ catridge. The extracted bile acids were labeled with 2-bromoacetyltriphenylene in acetonitrite using 18-crown-6-ether as a catalyst. Derivatized bile acids were separated from the individual bile acids on a reversedphase column (Chemcosorb 5-ODS-H) using acetonitrile-methanol-water(10:50:30) as a mobile phase and monitored by an UV-detector at 254nm. Linearities of calibration curve were obtained between 4 ng and 24 ng, and recoveries from bear gall bladder sample were higher than 94%.

• Journal of Pharmaceutical Investigation
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• v.37 no.3
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• pp.187-192
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• 2007

A reversed phase HPLC analysis of atorvastatin (AS) standard solution was performed using diclofenac (DF) as internal standard. Column oven temperature, flow rate and the composition of the mobile phase were varied in order to determine a practical system setup using a C18 column and UV detector. Two C18 columns of different length were compared regarding their influence on the AS peak shape. Based on these preliminary experiments a validation study was performed utilizing a C18 column at $62^{\circ}C$ with a mobile phase consisting of sodium phosphate buffer (0.05 M, pH 4.0), methanol and acetonitrile (40:50:10, v/v/v). The detection limit for AS was $0.1{\mu}g/ml$ and inter- and intra-day calibration curves were linear over a concentration range of $0.2-50{\mu}g/ml$. Accuracy and precision were satisfactory in the AS concentration range of $0.5-50{\mu}g/ml$.

• Journal of Food Hygiene and Safety
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• v.10 no.3
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• pp.169-174
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• 1995

Piperine, component of pure ground black pepper, has strong stimulative and hot. Analytical method for piperine was developed by high performance liquid chromatography. Analytical conditions are as follows, mobile phase is 70% methanol, detector UV 343 nm (0.05 AuFs), column is Novapak 5 C18 (15 cm $\times$ 4.6mm), flow rate is 1.0ml/min, chart speed is 0.25 cm/min and injection volume is 20 ul. Analytical results are as follows that relative standard deviation is 1.15%, calibration curve is y=170473.1x-7848.5 (R2=0.999) that shows good linearity. Standard solution of piperine is stable up to 10 hr and content of piperine in pureground black pepper is 4.97$\pm$0.86% Retention time of piperine in HPLC method is about 7 min. Therefore, the developed HPLC method including simple pretreatment of sample will be contribute to quality mangement.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.12
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• pp.1799-1803
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• 2003

The possibility of lycopene affecting egg yolk pigmentation was studied with lycopene diets containing 0, 4, 8, and $12{\mu}g/g$ meal, respectively. The addition of lycopene above $4{\mu}g/g$ meal significantly improved yolk color after four days of supplementation. The transfer of lycopene into egg yolk was confirmed by thin layer chromatography, and high-performance liquid chromatography-mass spectrometry (HPLC-MS). The deposition rate of lycopene into egg yolk was approximately 2%, which was quantitatively determined using a HPLC with a UV detector. The result indicates that lycopene is a good candidate for egg yolk pigmentation and for making functional eggs.

• YAKHAK HOEJI
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• v.35 no.4
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• pp.288-294
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• 1991

A new fluorescent derivatizing reagent was developed to be used in HPLC for the trace determination of primary and secondary amines. This new reagent, 1-(N,N-dimethylamino)pyrene-6-sulfonyl chloride, was synthesized by the chlorination of sodium 1-(N,N-dimethylamino)pyrene-6-sulfonate which was obtained from 1-(N,N-dimethylamino)pyrene after sulfonation. Ephedrine and norephedrine were derivatized quantitatively by this reagent. The optimum conditions for the derivatization such as pH, reagent concentration, reaction time and reaction temperature ware examined. The structures of derivatives were identified by IR, $^{1}$H-NMR and MS methods. The fluorescence properties and the stability of the derivatives were examined. The derivatives were separated on silica column with an isocratic elution using the mixture of n-hexane and ethylacetate and monitored by fluorescene detector. Linear calibration curves were obtained and detection limits in a 10 $\mu$l injection volume were 5 picomole for ephedrine and norephedrine.

• Herbal Formula Science
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• v.18 no.2
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• pp.251-257
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• 2010

Objectives : To develop and validate High-performance liquid chromatography-photodiode array methods for simultaneous determination of two constituents in Oryeong-san(ORS). Methods : Reverse-phase chromatography using a Gemini C18 column operating at $40^{\circ}C$, and photodiode array(PDA) detection at 280 nm, were used for quantification of the two marker components of ORS. The mobile phase using a gradient flow consisted of two solvent systems. Solvent A was $H_2O$ and solvent B was acetonitrile. Results : Calibration curves were acquired with correlation coefficient ($r^2$)>0.9999, and the relative standard deviation(RSD) values(%) for intra- and inter-day precision were not exceed 1.0%. The recovery rate of each compound was in the range of 93.01-104.16%, with an RSD less than 2.0%. The contents of two compounds in ORS were 1.10-3.72 mg/g. Conclusions : The established HPLC method will be helpful to improve quality control of ORS.