• 생명과학회지
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• 제15권1호
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• pp.136-140
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• 2005

다양한 라세믹 에폭사이드 기질에 대한 입체선택적 가수분해 반응을 촉매하는 epoxide hydrolase 활성을 측정할 수 있는 미생물 세포 기반의 자외선 활성 분석법을 최적화하였다. 2.5 mg/ml의 세포 농도에서도 비교적 쉽게 흡광도 변화량을 인식할 수 있는 흡광도 범위인 0.5 이상을 얻을 수 있고, 반응 동력학 분석에도 응용할 수 있었다. 기존의 GC, HPLC 분석 법 보다 분석 시간을 줄일 수 있으며, 효소를 별도로 분리$\cdot$정제하지 않고 미생물 세포 자체의 epoxide hydrolase활성 분석이 가능하므로 상업적 특성이 우수한 epoxide hydrolase을 가진 미생물을 효율적으로 선별하는데 응용될 수 있을 것으로 기대된다.

• Bulletin of the Korean Chemical Society
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• 제34권9호
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• pp.2760-2764
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• 2013

Geniposide is a biologically active ingredient of gardenia fruit. A liquid chromatography-tandem mass spectrometric method was developed and validated for the determination of geniposide in rat plasma. The plasma samples were pretreated by solid-phase extraction and introduced into a BDS Hypersil $C_{18}$ column ($50{\times}2.1mm$, $5{\mu}m$) for chromatographic separation. The mobile phase consisted of 0.1% formic acid and 0.1% formic acid in acetonitrile, and gradient elution was performed at a flow rate of 0.25 mL/min. For mass spectrometric detection, multiple reaction monitoring was performed via an electrospray ionization source in positive mode. The calibration curve for geniposide was linear ($r^2=0.997$) in the concentration range of $0.005-1{\mu}g/mL$. The intra- and inter-day accuracies and precisions fulfilled the required criteria (${\pm}15%$). The developed method was subsequently used for pharmacokinetic analysis of geniposide after oral administration to rats at a dose of 50 mg/kg. The mean maximum plasma concentration of geniposide was $0.68{\pm}0.29{\mu}g/mL$ at $0.44{\pm}0.13h$, and the mean area under the plasma concentration versus time curve was $1.46{\mu}g{\cdot}h/mL$.

• 대한화장품학회지
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• 제38권1호
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• pp.33-41
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• 2012

네일락카와 헤어스프레이 같은 화장품에 존재하는 미량의 프탈레이트를 정량분석하기 위하여, 가스크로마토그래피와 질량분석기를 사용한 효과적이면서 환경친화적인 분석방법을 개발하였다. 이들 화장품들은 다량의 유기용매를 함유되어 프탈레이트를 분석하기 위하여 널리 사용되는 시료의 클린업 방법이 적합하지 않았다. 더군다나 미량의 프탈레이트 분석시에는 실험과정 중에서의 오염으로 인해 실제보다 높은 분석값을 산출하게 되는 경우가 매우 많다. 이에 정확한 함량분석 및 이차오염을 방지하기 위해 유기용매를 사용하여 시료를 직접 희석하는 시료 전처리를 적용하였다. 이 분석방법은 높은 정확성, 분석감도, 그리고 시료전처리를 간략히 할 수 있는 이점을 가진다. 화장품에서의 검출되는 빈도가 높고, 사람과 동물에 영향을 미치는 환경호르몬으로 보고되는 dibutyl phthalate (DBP)와 di (2-ethylhexyl) phthalate (DEHP) 두 종의 프탈레이트를 분석대상으로 선정하였다. 정량시 그 정확도 향상을 위해서 내부표준물질로 두 물질의 중수소치환체인 DBP-$d_4$,와 DEHP-$d_4$를 사용하였다. 시험법의 유효화를 시행한 결과 본 시험법이 ppm 농도의 프탈레이트 정량분석에 적합함을 확인하였으며, 네일락카와 헤어스프레이 제품에 약 $25{\mu}g/g$의 농도로 표준물질을 첨가하여 분석한 회수율은 95 - 106.1 % 범위였고, % 상대표준편차 값은 3.9 % 이하였다.

• Natural Product Sciences
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• 제17권2호
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• pp.147-159
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• 2011

A high-performance liquid chromatography-electrospray ionization-tandem mass spectrometric method was developed to determine simultaneously eight marker constituents of Forsythiae fructus, and subsequently applied it to classify its two botanical origins. The marker compounds of Forsythia suspensa were phillyrin, pinoresinol, phillygenin, lariciresinol and forsythiaside; those of F.viridissima were arctiin, arctigenin and matairesinol. Separation of the eight analytes was achieved on a phenyl-hexyl column (150${\times}$2.0 mm i.d., 3 ${\mu}M$) using gradient elution with the mobile phase: (A) 10% acetonitrile in 0.5% acetic acid, (B) 40% aqueous acetonitrile. A few fragment ions specific to the types of lignans, among the product ions generated by collisonally induced dissociation (CID) of molecular ion clusters, such as [M-H]$^-$ or [M+OAc]$^-$ were used not only for fingerprinting analysis but for the quantification of each epimer by using multiple-reaction monitoring mode. It was shown good linearity ($r^2{\geq}$ 0.9998) over the wide range of all analytes; intra- and inter-day precisions (RSD, %) were within 9.14% and the accuracy ranged from 84.3 to 115.1%. The analytical results of 40 drug samples, combined with multivariate statistical analyses - principal component analysis (PCA) and hierarchical cluster analysis (HCA) - clearly demonstrated the classification of the test samples according to their botanical origins. This method would provide a practical strategy for assessing the authenticity or quality of the herbal drug.

• 한국축산식품학회지
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• 제29권4호
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• pp.482-486
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• 2009

The aim of this study was to optimize a simple, fast, and economical analysis procedure for the determination of 16 different pesticides in raw milk via GC/MSD. Analyses were performed via gas chromatography with electron impact mass spectrometric detection in the selected ion monitoring mode (GC/MSD-SIM) using Pentachloronitrobenzene as the internal standard. The modified sample preparation methodology was based on the Pesticide Analytical Manual (PAM) of the FDA concerning fat extraction, ACN-ether partitioning, and clean-up of the Sep-Pak florisil cartridge. The modified methodology for the determination of the 16 pesticides was validated. The range of LOQs of the 16 pesticides was likely three times lower than their Maximum Residence Levels (MRLs). The recoveries of most of the pesticides were acceptable at the fortification levels of 0.5 and 1.0 ${\mu}g/mL$ and their RSD (%) level was less than 20%. None of the 16 pesticides were detected in the selected raw milk samples.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.275-275
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• 2013

Formation and characterization of self-assembled monolayers (SAMs) on various surfaces are the essential basis for many other applications, including molecular switches, biosensors, microfluidics, and fundamental studies in surfaces and interfaces. To improve the performance at these applications, it is a key to control the quantity of each molecule in various mixed SAMs on the surface. In this study, using mixed SAM of carbamate-based hydroquinone (HQ)-PhBr and11-mercaptoundecanol, the quantitative mass spectrometric method of mixed SAM was developed based on comparison study with XPS and FT-IR methods. In addition, our method was applied to another mixed SAM of biotinylated PEG alkane thiol and 11-mercaptoundecanol for verification purpose. Time-of-flight secondary mass spectrometry (ToF-SIMS) analysis was performed to identify and quantify each molecule of mixed SAM along with principal component analysis (PCA). Since there is no matrix effect in the X-ray photoelectron spectroscopy (XPS) and Fourier transform-infrared (FT-IR) techniques, we compared ToF-SIMS results with XPS and FT-IR results. Because PCA results from ToF-SIMS analysis are well matched with XPS and FT-IR results from both mixed SAMs, we are expecting that our method will be useful to identify and quantify each molecule in various mixed SAMs.

• 대한화학회지
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• 제46권5호
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• pp.419-437
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• 2002

산성조건에서 $H_2O_2$에 의한 $Fe^{2+}$ 이온의 산화($Fe^{2+}{\to}Fe^{3+}$)반응과 $Fe^{3+}$이온과 $SCN^-$이온이 결합하여 붉은색 Fe$(SCN)^{3-x}_x$ 이온을 형성하는 착화반응을 도입한 흐름주입분석기법을 사용하여 $Fe^{2+}$이온과 $Fe^{2+}$이온이 공존하는 시료용액 중 각 이온들의 동시정량을 위한 분석법을 개발하였다. 이 분석법은 개별 이온들에 대한 정량단계에 앞서 혼합시료의 전처리($Fe^{2+}$이온의 예비산화 혹은 $Fe^{2+}$이온의 예비환원)단계를 거쳐야 하는 기존의 분석법들과는 달리 두가지 단계들을 동시에 수행할 수있다는 장점을 가진다. 이 분석법의 측정한계는 [$Fe^{2+}$]=6.00${\times}10^{-7}$M 이었다.

• Journal of Pharmaceutical Investigation
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• 제37권3호
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• pp.179-186
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• 2007

A simple, sensitive and selective liquid chromatographic/tandem mass spectrometric method (LC-MS/MS) was developed and validated for doxifluridine and 5-fluorouracil (5-FU) quantification in dog heparinized plasma. Sample preparation was based on liquid-liquid extraction using a mixture of isopropanol/ethyl acetate (1/9 v/v) to extract doxifluridine, 5-FU and 5-chlorouracil (5-CU, an internal standard) from plasma. Chromatography was performed on a C-18 analytical column and the retention times were 2.7, 1.5 and 1.7 min for doxifluridine, 5-FU and 5-CU, respectively with shorter analysis time within 5 min than previously reported methods. The ionization was optimized using ESI negative mode and selectivity was achieved by tandem mass spectrometric analysis by multiple reaction monitoring (MRM) using the transformations of m/z 244.8>107.6, 129.0>42.0 and 144.9>42.1 for doxifluridine, 5-FU and 5-CU, respectively. The achieved low limit of quantification was 20.0 ng/mL and the assay exhibited linear range of 20-2000 ng/mL ($R^2>0.99957$ for doxifluridine and $R^2>0.99857$ for 5-FU), using $100{\mu}L$ of plasma. Accuracy and precision of quality control samples for both doxifluridine and 5-FU met KFDA and FDA Guidance criteria of 15% for accuracy with coefficients of variation less than 15%. This method demonstrated adequate sensitivity, specificity, accuracy, precision and stability to support the simultaneous analysis of doxifluridine and 5-FU in dog plasma samples in pharmacokinetic and bioequivalence studies.

• Clinical and Experimental Pediatrics
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• 제59권sup1호
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• pp.45-48
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• 2016

Short-chain acyl-CoA dehydrogenase deficiency (SCADD) is a rare autosomal recessive mitochondrial disorder of fatty acid ${\beta}$-oxidation, and is associated with mutations in the acyl-CoA dehydrogenase (ACADS) gene. Recent advances in spectrometric screening for inborn errors of metabolism have helped detect several metabolic disorders, including SCADD, without symptoms in the neonate period. This allows immediate initiation of treatment and monitoring, so they remain largely symptomless metabolic disease. Here, we report a 15-month-old asymptomatic male, who was diagnosed with SCADD by newborn screening. Spectrometric screening for inborn errors of metabolism 72 hours after birth revealed an elevated butyrylcarnitine (C4) concentration of $2.25{\mu}mol/L$ (normal, < $0.99{\mu}mol/L$). Urinary excretion of ethylmalonic acid was also elevated, as detected by urine organic acid analysis. To confirm the diagnosis of SCADD, direct sequencing analysis of 10 coding exons and the exon-intron boundaries of the ACADS gene were performed. Subsequent sequence analysis revealed compound heterozygous missense mutations c.164C>T (p.Pro55Leu) and c.1031A>G (p.Glu344Gly) on exons 2 and 9, respectively. The patient is now growing up, unretarded by symptoms such as seizure and developmental delay.

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 1990년도 Proceedings of International Symposium on Korean Ginseng, 1990, Seoul, Korea
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• pp.75-78
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• 1990

Two lignanes, Comp.-I, mp 108-1$0^{\circ}C$ and Comp.-II, mp 50-52$^{\circ}C$ were isolated from Korean ginseng extract by repeated column chromatographic purification. Comp-1 was identified as gomisin-N and Comp. -II as gomisin-A by spectrometric analysis, both of which have already been described as the anti-hepatotoxic lignin components of Schizandra chinensis Bail.