• 한국식품위생안전성학회지
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• 제10권3호
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• pp.189-197
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• 1995

Analytical method for synephrine and octopamine in citrus fruits, drinks containing citrus fruit, and human urine was developed using gas chromatography / mass spectrometry(GC/MS), Silylation with MSTFA, acetylation with MBTFA, and trimethylsilylation with MSTFA followed by trifiuoroacetylation with MBTFA were compared. The selective derivatization of synephrine and octopamine was optimized with two derivatizing reagents ; MSTFA and MBTFA. The ion at m/z 267 was monitored to characterize the benzyl group of the both compounds. Synephrine was detected in the concentrations of 0.46∼1.88 ug/g for citrus fruits and 1.2∼8.1 ug/ml for drinks. The urinary excretion data of synephrine showed the highest concentration at the period of 8-20 hours after drinking orange juices and total amounts of its urinary excretion calculated as a parent compound was 11-14% of a dose during 48 hours. Octopamine was not detected in citrus fruits, drinks, and human urine.

• Mass Spectrometry Letters
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• 제9권3호
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• pp.77-80
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• 2018

The focus of this paper is to present techniques to overcome certain difficulties in quantitative analysis with a time-of-flight mass spectrometer (TOF-MS). The method is based on conventional solid-phase extraction, followed by reversed-phase ultra high performance liquid chromatography of the extract, and mass spectrometric analysis. The target compounds included atenolol, atrazine, caffeine, carbamazepine, diclofenac, estrone, ibuprofen, naproxen, simazine, sucralose, sulfamethoxazole, and triclosan. The matrix effects caused by high concentrations of organic compounds in wastewater are especially significant in electrospray ionization mass spectroscopy. Internal-standard calibration with isotopically labeled standards corrects the results for many matrix effects, but some peculiarities were observed. The problems encountered in quantitation of carbamazepine and triclosan, due to nonlinear calibration were solved by changing the internal standard and using a narrower mass window. With simazine, the use of a quadratic calibration curve was the best solution.

• Journal of Pharmaceutical Investigation
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• 제31권3호
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• pp.197-200
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• 2001

Lectin-conjugated ellagitannin (LET), a newly introduced melanoma-specific antitumor agent which has been synthesized by conjugation of wheat germ agglutinin as a lectin with praecoxin A as an ellagitannin, was encapsulated into sterically stabilized liposomes (SSL). Modified Folin phenol method was established for the quantitation of LET contents in liposomal formulations protein employing the standard calibration curve with bovine serum albumin. After removal of phospholipid by organic solvent extraction, which interferes the specific selectivity of the Folin-Ciocalteu reagent with the protein, recovery of LET was $94.5{\pm}2.3%$ and the encapsulation efficiency was revealed as $37.8{\pm}5.9%$ for 2.5 mg/ml LET solution.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.400.3-401
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• 2002

Levosulpiride is the levo-enantiomer from of racemic sulpride. abenzamide derivative selectively inhibition doparninergic D2 receptos at the trigger zone both in the central nervous system and in the gastrointestinal tract. We report a rapid and sensitive HPLC method using reverse phase C 18 column with fluorescence detection for separation and quantitation of levosulpiride in plasma. Tiapride was used as an internal standard. After adding an internal standard. levosulpiride in 800 ${\mu}l$ of plasma was extracted under basic conditions with ethyl acetate and methylene chloride. (omitted)

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.401.3-402
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• 2002

Enalapril (ENP) maleate is effective drug for the treatment of renivascular hypertension and heart failure. ENP acts as inhibitor of the enzyme angiotensin-convertase (ACE-inhibitor) and metabolized to enalaprilat (ENPT), which is the active metabolite that is really responsible for the therapeutic action. In the present study, a sensitive and rapid liquid chromatography/ electrospray ion trap tandem mass spectrometry (LC/MS/MS) method combined with high-throughput solid phase extraction (SPE) has been developed and validated for the simultaneous quantitative determination of ENP and ENPT in human plasma. (omitted)

• 대한화학회지
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• 제38권10호
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• pp.741-748
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• 1994

남조류의 독성물질인 microcystin을 HPLC로 분석하기 위해 지금까지는 ODS cartridge를 사용하였으나 본 연구에서는 CN cartridge를 사용하는 새로운 분석 방법을 시도하였다. CN cartridge는 0.5M 초산 용액으로 처리되었으며 Microcystins RR과 LR을 용리시키기 위해 30% Acetonitrile 용액이 사용되었다. CN cartridge를 이용하는 분석 방법이 기존의 ODS cartridge를 이용하는 방법보다 훨씬 더 정확한 정량을 할 수 있었다. 특히 Microcystin LR의 경우 피크 면적에서 현저한 차이를 보였다.

• Toxicological Research
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• 제7권1호
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• pp.21-27
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• 1991

We developed a simple method to determine benzodiazepines in biological samples using electron capature detectors and nitrogen-phosphorous detectors. The extraction of 13 benezodiazepines in urine at pH 9.5 with toluene and its analysis in GC/NPD showed the peaks in 9-16 min. In this retention time range, the biological backaground was fairly low and the drugs could be identified in low concentrations. The benzodiazepines in urine samples were screened by the fluorescence polarization immunoassay and positive samples were confirmed by the GC/NPD method.

• Toxicological Research
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• 제7권1호
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• pp.29-35
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• 1991

Barbiturates are commonly abused tranquilizer and a rapid method to determine these drugs in biological samples is needed. In this study, was screened barbiturates in urine specimens by the fluorescence polarization immunoassay method(FPIA) and the positive samples were confirmed and identified by the more definitive GC/MS method. Fifteen positive smples which have barbiturate values higher than 0.5 ng/ml were analyzed by the GC/MS method. Eight samples were identified as phenobarbital and five samples were identified as crotilbarbitone.

• 생약학회지
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• 제51권1호
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• pp.78-85
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• 2020

In this study, we shortly introduced the HPLC method validation guideline for the analysis of functional food which was released from the Ministry of Food and Drug Safety of Korea in Dec 2018. The HPLC method validation was performed through the aforementioned HPLC method validation guideline in order to quantitate scopoletin content from the hot-water extract powder of Artemisia annua Linné. The HPLC method was validated by evaluating specificity, accuracy, precision, limit of quantitation and linearity. All parameters were in the suitable ranges which are designated in the guideline, which indicated the current HPLC method is reliable to quantitate the scopoletin content from the hot-water extract of A. annua.

• Bulletin of the Korean Chemical Society
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• 제32권2호
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• pp.489-497
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• 2011

The proposed method for an effective assay of Cd, Cr and Pb in several polymer samples has been validated. The determination was carried out using ICP-OES after a high pressure asher (HPA) digestion at pressure and temperatures up to 13 MPa and $320^{\circ}C$, respectively. Polymer based materials were totally oxidized with nitric acid in a HPA chamber and determined by ICP-OES. Validation parameters such as linearity, matrix effect, limit of dectection (LOD), limit of quantitation (LOQ), accuracy and precision (repeatibility, intermediate precision and reproducibility) were assessed. The LOD and LOQ in the sample were ranged from 0.98 to 1.18 mg $kg^{-1}$ and 2.93 to 3.55 mg $kg^{-1}$, respectively, relying on the analyte. The proposed method had a good accuracy and precision for repeatability, intermediate precision with respect to days and analysts and reproducibility expressed as inter-laboratory study. The developed method was simple to use, suitable and applicable to various kinds of polymers.