• Mass Spectrometry Letters
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• 제14권3호
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• pp.104-109
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• 2023

Anabolic-androgenic steroids (AAS) are used illegally to enhance muscle development and increase strength and power. In this study, a reliable, and sensitive quantitative method was developed and validated using heptafluorobutyric acid anhydride (HFPA) derivatives for the simultaneous detection of prohibited AAS (testosterone [TS], boldenone [BD], 5α-estrane-3β,17α-diol [EAD]) using gas chromatography-tandem mass spectrometry (GC-MS/MS). For processing the samples, solid phase extraction, methanolic hydrolysis, and liquid-liquid extraction were used. For detection using mass spectrometry, the multiple reaction monitoring (MRM) mode was used with the electron ionization (EI) positive mode. The method was evaluated for selectivity, linearity, lower limit of quantification, intra- and inter-day precision, accuracy, and stability. The results showed that the method was accurate and reproducible for the quantitation of the three steroids. The developed method was finally applied to the analysis of a suspect gelding urine sample received from the Asian Quality Assurance Program (AQAP).

• Bulletin of the Korean Chemical Society
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• 제31권5호
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• pp.1159-1164
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• 2010

Several triterpenoid saponins from root of Pulsatilla koreana Nakai (Ranunculaceae) were studied and their biological activities were reported. It is difficult to analyze triterpenoid saponins using HPLC-UV due to the lack of chromophores. So, evaporative light scattering detection (ELSD) is used as a valuable alternative to UV detection. More recently, a charged aerosol detection (CAD) has been developed to improve the sensitivity and reproducibility of ELSD. In this study, we developed and validated a novel method of high performance liquid chromatography coupled with a charged aerosol detector for the simultaneous determination of four triterpenoid saponins: pulsatilloside E, pulsatilla saponin H, anemoside B4 and cussosaponin C. Analytes were separated by the Supelco Ascentis$^{(R)}$ Express C18 column (4.6 mm ${\times}$ 150 mm, 2.7 ${\mu}m$) with gradient elution of methanol and water at a flow rate of 0.8 mL/min at $30^{\circ}C$. We examined various factors that could affect the sensitivity of the detectors, including various concentrations of additives, the pH of the mobile phase, and the CAD range. Linear calibration curves were obtained within the concentration ranges of 2 - 200 ${\mu}g$/mL for pulsatilloside E, anemoside $B_4$ and cussosaponin C, and 5 - 500 ${\mu}g$/mL for pulsatilla saponin H with correlation coefficient ($R^2$) greater than 0.995. The limit of detection (LOD) and quantification (LOQ) were 0.04 - 0.2 and 2 - 5 ${\mu}g$/mL, respectively. The validity of the developed HPLC-CAD method was confirmed by satisfactory values of linearity, intra- and inter-day accuracy and precision. This method could be successfully applied to quality evaluation, quality control and monitoring of Pulsatilla koreana.

• 한국식품위생안전성학회지
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• 제5권3호
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• pp.159-164
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• 1990

To detect and quantitation residual antibiotics and antibacterial agents in meats, we performed a biological assay employing the three microorganisms Bacillus subtilis ATCC 6633, Micrococcus luteus ATCC 9341, and Bacillus cereus var. mycoides ATCC 11778 for the screening purpose and developed a Gas Chromatography-mass Spectrometry(GC/MS) analysis for the confirmation and quantiation. In the biological assay (paper disk method), three test solution are used depending on the character of the residual antibiotics and antibacterial agents, follow by a simple clean up procedure which includes homogenization with Mcilvaine buffer, defatting with includes homogenization with Mcilvaine buffer, defatting with hexane, extraction with chloroform, clean-up by Sep-Pak $C_{18}$ and Bakerbond SPE carboxylic acid column. The chloroform layer is used for the analysis of sulfa agents. macrolides antibiotics and antibacterial agents, Adsorbed materials in the Sep-Pak $C_{18}$ were also employed for th analysis of penicillins and tetracyclines. Effluents from the Sep-Pak $C_{18}$ were cleaned-up one more by Bakerbond 10 SPE COOH column and employed for the analysis of aminoglycosides. In the instrumental analysis by using the GC/MSD, residual antibiotics and antibacterial agent were quantitated by selected ion monitoring (SIM) mode after derivatization. A simultaneous analysis of six residual antibiotic and antibacterial agent such as oxytetracycline, penicillin, ampicillin, choliraphenicol and thiamphenicol was developed with simple cleanup procedures revealing good recovery and reproducibility. Also, simultaneous detection of macrolides antibiotics such as erythromycin, spiramycin, and oleandomycin was developed after acid hydrolysis due to their large molecular structures. Because of the high reproducibility and selectivity of these two methods, it is very desirable that the combination of the two methods be used in the bioassay for the screening of residual antibiotics and antibacterial agent and that GC/MSD analysis be used for the confirmation and quantitation.

• 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.

• 대한환경공학회지
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• 제27권12호
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• pp.1257-1262
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• 2005

유기염소계 농약은 약 20년 이상 사용이 금지되어 국내에서는 거의 분석이 수행되고 있지 않다. 유기염소계 농약의 환경 중에서 오래 잔류되어 지속적인 감시가 필요하나 유기인계 농약만이 현재 국내에서 조사되고 있다. 유기염소계와 유기인계 농약을 GC/MSD를 이용하여 동시 분석을 시도하였다. Pressurized fluid extraction(PFE) 방법을 이용하여 시료를 추출하였으며 PFE 방법은 짧은 추출 시간과 적은 용매에도 soxhlet 추출 방법과 유사한 효율을 나타냈다. 토양 및 잔디 시료에 대한 스파이크 시료의 회수율은 $52{\sim}154%$ 범위로 평균값은 64%였다. 이 농약들에 대한 분석 검출 한계는 $3.4{\sim}10.6\;{\mu}g/kg$이었고 조사된 9개의 골프장 중 5개에서 endosulfan, fenitrothion, diazinon이 검출되었다.

• 대한지하수환경학회지
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• 제1권1호
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• pp.6-9
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• 1994

지하수의 Ar/$N_2$가스의 비율은 탈질화(denitrification)의 정도를 측정하는 하나의 방법으로 사용된다. (Barnes et al., 1975; Vogel et al., 1981; Mariotti et al., 1988) 그 비율 측정은 일반적으로 질량분석기 (Mass Spectrometer)를 사용한다. 본 실험에서 사용한 Mass Spectrometer는 일반적인 Static Mass Spectrometer가 아닌 Ar과 $N_2$을 시간적으로 동시에 측정하여 오차를 줄일 수 있는 VG Optima isotope ratio Mass Spectrometer를 사용하였다. 두 지역 지하수의 Ar/$N_2$가스의 비율을 측정한 결과 Site 1(Grand Island, NE)의 경우 대기가스가 포화된 증류수의 Ar/$N_2$가스 비율인 0.026보다 낮은 0.015-0.018로서 탈질이 일어났음을 알 수 있으며, Site 2(Shelton, NE)의 경우 0.023-0.02로서 탈질이 일어나지 않음을 알 수 있다. 본 실험의 목적은 지하수에 응해되어 있는 Ar/Nitrogen의 비율을 정확히 측정하는 방법을 개발하므로서 탈질의 정도를 정확히 측정하며 탈질의 전개 과정을 관찰하기 위한 것이다.

• 한국수산과학회지
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• 제39권6호
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• pp.454-459
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• 2006

A simultaneous high-performance liquid chromatography assay method for amoxicillin and ampicillin in fish products was developed, evaluated, and validated by monitoring these antibiotics in fish samples obtained from aquaculture and distribution. The recovery rate of this method was higher than those of conventional methods and was 95.3-106.6% for amoxicillin and 81.4-92.4% for ampicillin. Our pretreatment procedure sufficiently removed or reduced materials affecting HPLC analysis, such as low-molecular-weight substances. The performance limit of this method was evaluated as 0.01 ppm of amoxicillin and ampicillin in fish muscle. Finally, 171 fish samples, including olive flounder (Paralichthys olivaceus), common sea bass (Lateolabrax japonicus), and black rock fish (Sebastes schlegeli) collected from fish farms in the coastal area between April and September 2005 were analyzed to evaluate the overall efficiency of the method and to monitor the actual of amoxicillin and ampicillin usage in fish farms. The results indicated that the developed method was suitable for analyzing amoxicillin and ampicillin in fish muscle, and determined that those antibiotics were being used for fish farming but were not detected in fish samples during the shipping and distribution stages.

• 분석과학
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• 제23권6호
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• pp.572-578
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• 2010

본 연구에서는 하천수 중 6종의 의약물질(cephradine, cefadroxil, penicillin G, vancomycin, iopromide, and fenbendazole)에 대한 전처리법과 분석 방법을 확립하였다. 하천수 중의 분석물질을 HLB(Hydrophilic-Lipophilic Balanced) 카트리지를 사용하여 추출/정제 및 농축하였다. HPLC/ESI-MS/MS를 이용하여 6종의 물질들을 동시에 분석하였다. Fenbendazole을 제외한 의약물질은 71.1~92.6% 범위의 양호한 회수율을 나타내었고, 상대표준편차는 11.2% 이하로 나타났다. 정량분석을 위해서 0.007~1.2 ng/mL 범위에서 $r^2$=0.99 이상의 높은 직선성을 나타내는 검량선을 얻었다. 검출한계(LOD)와 정량한계(LOQ)는 각각 7.2~128.7 pg/mL, 23.8~429.1 pg/mL로 나타났다. 이 분석 방법은 하천수 중 의약품에 대한 모니터링에 유용하며, 하천수 중 iopromide과 fenbendazole은 높은 농도로 검출되었다.

• 한국항공우주학회지
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• 제32권7호
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• pp.43-50
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• 2004

변형률과 파손선호를 동시에 계측하기 위하여 이중복조기를 갖는 광섬유 브래그 격자 센서시스템을 제안하였다. 이중복조기는 가변 패브리-페로 필터를 사용하여 변형률과 같이 변화가 큰 저주파신호를 측정하는 복조기와 수동 마흐 -젠더 간섭계를 사용하여 충격이나 파손신호와 같이 미세한 크기의 고주파 신호를 측정하는 복조기로 구성된다. 제안된 광섬유 브래그 격자 센서시스템을 이용하여 인장하중을 받는 직교적층 복합재 구조물의 변형률과 파손신호를 동시에 계측할 수 있었다. 하나의 광섬유 브래그 격자 센서로 측정한 변형률과 파손신호를 분석한 결과, 복합재 시편의 90도 층에서 기지 균열이 발생할 때 급격한 변형률 변이가 유발되고, 최대 수백 킬로헤르츠에 이르는 주파수 성분을 가진 진동신 호가 발생함을 알 수 있었다.

• 약학회지
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• 제55권2호
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• pp.145-153
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• 2011

A simultaneous detection and quantification method for determining the Phenylalkylamine derivatives, such as methamphetamine (MA), amphetamine (AM), 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxyamphetamine (MDA), ketamine (KT), norketamine (NKT), phentermine (PT), fenfluramine (FFA) and phenmetrazine (PM), in oral fluid was developed and validated according to international guidelines. The validated method was applied to actual oral fluid samples collected from drug abuse suspects. The recovery of phenylalkylamines from oral fluid collection devices was also assessed. Oral fluid specimens from 20 drug abuse suspects submitted by the police were collected using Salivette$^{TM}$, Quantisal$^{TM}$ or direct expectoration. The samples were screened using a biochip array analyzer. For confirmation, the samples were analyzed by GC-MS in selected-ion monitoring (SIM) mode after extraction using automated SPE with a mixed-mode cation exchange cartridge and derivatization with trifluoroacetic anhydride (TFAA). The results from the immunoassay were consistent with those from GC-MS. All the oral fluid samples gave positive results for MA, AM, PT and/or PM. The detection of phenylalkylamines in oral fluid can provide a better indication of recent use than urine or hair. Therefore, the oral fluid specimen was useful for demonstrating phenylalkylamines abuse in the driving under the influence of drug (DUID) as an alternative specimen for urine.