• 한국물환경학회지
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• 제25권4호
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• pp.597-605
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• 2009

Algae bloom occurred in reservoir in summer can cause taste and odor in water and disturb the flocculation and sedimentation processes in water treatment plant and cause sand filter plugging. It was also reported that microcystins, anatoxin and saxitoxin released from cyanobacteria had acute toxic effects on liver and nervous system. For these reasons, many advanced countries inclusive of WHO set the guideline for these toxins and cyanotoxins have been managed with regular monitoring in Korea as well. However, complex sample preparation steps such as a solid phase extraction (SPE) and derivatization are required with an existing analysis method with HPLC. We needed to improve an analysis method for low extraction efficiency and long sample preparation time. In this study, we have established a new LC/MS/MS method which can simultaneously determine 6 cyanotoxins (Microcystins-LR, Microcystins-RR, Microcystins-YR, Anatoxin-a, Saxitoxin, Neosaxitoxin) with only simple filtration step. When $75{\mu}L$ filterated sample was injected onto the LC-MS/MS, the recovery ranged from 86% to 112% and the MDL was $0.025{\sim}0.581{\mu}g/L$. We can make the MDL be lower than the guideline ($1{\sim}3{\mu}g/L$) of advanced countries with simple preparation.

• 생약학회지
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• 제54권1호
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• pp.38-43
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• 2023

A simple and accurate assay was developed for the quantitative analysis of 1-deoxynojirimycin (1-DNJ) derived from the silkworm (Bombyx mori). Normal-phase high-performance liquid chromatography coupled with an evaporative light scattering detector (HPLC-ELSD) and a hydrophilic interaction liquid chromatography column was used. Various parameters were applied to optimize the analysis method. The limits of detection and quantification of 1-DNJ were 2.97 × 10^-3 and 9.00 × 10^-3 mg/mL, respectively. The calibration curve showed good linearity results. The concentration range and the r² value were 0.0625-1.0 mg/mL and 0.9997, respectively. The accuracy test demonstrated a significantly high recovery rate (89.95-103.22%). The relative standard deviation was ≤ 1.00%. Thus, a method for the accurate identification and quantitative analysis of 1-DNJ in silkworms was developed. Moreover, in this procedure, the process of derivatization of 1-DNJ, which was required in previous experiments, could be eliminated. This technique may be actively utilized for the development of pharmaceuticals and health functional foods using 1-DNJ.

• 분석과학
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• 제29권1호
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• pp.49-55
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• 2016

케톤체는 생체 에너지 생산과정이 탄수화물보다는 지방산의 의존도가 높을 때 생성되며, 과도한 분비는 당뇨병성 케토시스나 선천성 유전성 대사이상질환을 의심할 수 있는 근거가 된다. 따라서 이의 신속 정확한 분석법의 개발이 필요하다. 본 연구에서는 혈장을 제단백한 후 hydroxylamine을 가하여 60 ℃에서 30 분간 반응시켜 oximation 후 BSTFA를 가한 후 trimethylsilylation 유도체화하여 혈장 중에서 케톤체를 신속하게 정량할 수 있는 GC-MS/SIM 분석법을 개발하였다. 케톤체의 직선성의 범위는 0.001-250 μg/mL 이었고, 혈장에서의 검출한계는 0.1 pg 이었다. 직선성을 가지는 범위에서의 상관계수(R2)는 0.998-0.999이었고, 회수율은 1 μg/mL의 표준품을 첨가하였을 때 88.2-92.3 %, 10 μg/mL의 농도를 첨가하였을 때 89.5-94.8 % 였으며 RSD는 6.3-9.4 %였다. 이 분석법을 정상인과 케토시스 환자의 검체에 적용하여 벨리데이션 하였으며, 본 분석방법은 어린이나 성인의 당뇨성 케토시스나 여러 유전성대사질환 환자 중 케토시스를 보이는 환자의 혈장 중 β-hydroxybutyric acid/acetoacetic acid의 비를 계산하여 케톤체를 신속하고 효율적으로 임상검체 분석에 응용할 수 있음을 보여주었다.

• 대한환경공학회지
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• 제29권6호
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• pp.689-698
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• 2007

우리나라 수중 생물시료에 있는 알킬페놀류, 클로로페놀류 및 비스페놀 A의 정량분석을 위한 새로운 기술을 제시하였다. 우리나라 수중 생물시료에 있는 알킬페놀류, 클로로페놀류 및 비스페놀 A를 아세토니트릴로 추출한 다음 아세토니트릴 층을 2 시간동안 $-60^{\circ}C$에 냉동하였다(냉동필터). 또한, XAD-4를 이용한 고체상 추출 후, isobutoxycarbonyl(isoBOC) 또는 tert-butyldimethylsilyl(TBDMS) 유도체화 한 후 가스크로마토그래피/질량분석기-선택이온 모니터링 방법을 사용하였다. isoBOC 유도체화와 TBDMS 유도체화의 회수율은 $70.1\sim150.6%$와 $93.8\sim108.3%$이였으며, 선태이온 모니터링 방법을 이용한 비스페놀 A의 분석방법 검출한계는(MDLs) 각각 $0.062{\mu}g/kg$ 및 $0.010{\mu}g/kg$이었다 이 방법을 우리나라 수중 생물시료에 적용하였을 때, 11가지 페놀성 내분비계장애물질의 농도는 $0.675\sim1.970{\mu}g/kg$이었다.

• Archives of Pharmacal Research
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• 제21권6호
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• pp.651-656
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• 1998

A sensitive high-performance liquid chromatographic (HPLC) method for the determination of aloesin in plasma was developed. After solid-phase extraction from plasma and derivatization of aloesin and compound AD-1, which was prepared from aloesin as a internal standard, with 9-anthroylnitrile in the presence of quinuclidine, the derivatives were separated on a Inertsil ODS-3 column using acetonitrile/methanol/water (3:1:6) as a mobile phase, and detected fluorimetrically at 460nm with excitation at 360nm. The detection limit of aloesin was 3.2ng/ml in plasma (S/N=3).

• 약학회지
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• 제39권4호
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• pp.433-437
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• 1995

Optically pure(-)-and (+)-$\alpha$-hydroxy-$\alpha$-(p-chlorobiphenyl)acetic acids were prepared. The racemate was synthesized through three steps. By condensation of p-cnorobiphenyl with diethyl ketomalonate in the presence of SnCl$_{4}$, diethyl $\alpha$-hydroxy-$\alpha$-(p-chlorobiphenyl)malonate (1) was formed and subsequently ($\pm$)-$\alpha$-hydroxy-$\alpha$-(p-chlorobiphenyl)acetic acid (3) was obtained through hydrolysis and decarboxylation. For the separation of the racemate the classical resolution method, derivatization of a racemate by reaction with an optically pure compound was employed. In this case the optically pure compound were [R]-(+)-$\alpha$-methylbenzylamine and [S]-(-)-$\alpha$-methylbenzylamine. Diastereomeric salts between acids and bases could be easily separated by crystallization in absolute ethanol.

• 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.

• 대한의생명과학회지
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• 제21권4호
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• pp.241-247
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• 2015

Lactate and ketone bodies are considered biological markers for ketosis and several inherited metabolic disorders. In the current study, the specific ratios of lactate and ketone bodies as analytical tools for differential diagnosis of various lactic acidosis were devised. The study included a protein precipitation step following tert-butyldimethylsilyl derivatisation. Total run time was approximately 30 min including sample preparation and GS/MS analysis. The limits of detection were below 0.1 pg/mL over the targeted 4 analytes. The calibration curve was linear over the concentration range of $0.001{\sim}250{\mu}g/mL$ for pyruvate, beta-hydroxybutyrate, and acetoacetate ($R^2$ > 0.99). Inter-day accuracy and precision were 87.7~94.8% with RSD of 2.5~5.7% at 2 levels. Absolute recoveries (%) of target analytes were 87.0~98.4%. The method was validated for the quantification of lactate and ketone bodies for differentiation of lactic acidosis.

• 한국식품위생안전성학회지
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• 제10권4호
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• pp.239-247
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• 1995

Analytical method for saccharin in foods was developed using gas chromatography/mass spectrometry(GC/MS). Methylation with diazomethane, acetylation with MBTFA, and silylation with MSTFA and MTBSTFA were compared. Methylation of saccharin produced N-methylated saccharin as the major product and O-methylated saccharin as the minor one. Silylation of saccharin with MSTFA and MTBSTFA reasulted in the formation of the correponding O-silylated products, respectively. The derivatization of saccharin was optimized with MSTFA. The ions at m/z 240, 255, and 166 were monitored to characterize saccharin.

• Bulletin of the Korean Chemical Society
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• 제10권5호
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• pp.411-414
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• 1989

A new sensitive fluorimetric method for the determination of N-methylcarbamates, a class of well known insecticides, based on the derivatization with 7-chloro-4-nitrosobenz-2-oxa-1,3-diazole (NBD-Cl) has been developed. Unreacted NBD-Cl was eluted ahead of derivatized carbamates from C-18 bonded column. An argon ion laser was used as an excitation source of chromatographic eluents and its fluorescence signal was monitored with optical multichannel analyzer. The detection limits of various carbamates were about 100 pg range and the working curves were linear to $10^4-10^5$ nanogram ranges.