• 농약과학회지
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• 제18권4호
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• pp.296-313
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• 2014

토양환경 중 잔류농약 동시분석을 위해 124종의 농약을 대상으로 QuEChERS 전처리와 LC-MS-MS를 이용한 분석법을 개발하고자 하였다. QuEChERS 전처리 과정은 토양시료에 0.2N $NH_4Cl$ 용액 침지하고 1% acetic acid 포함 acetonitrile 용매로 추출 후 $MgSO_4$ 및 NaOAc로 salting out하고 PSA 50 mg, $C_{18}$ 50 mg, $MgSO_4$ 150 mg를 이용해 정제하였다. 분석법의 검증을 위해 양토 및 사양토 두 토양에서 0.005, 0.01, 0.02, 0.1 mg/kg 4수준으로 처리 후 회수율 실험을 실시하였다. 회수율 실험결과 Benfuracarb, Ethiofencarb, Pymetrozine, Pyrethrin 성분을 제외하고 나머지 성분들은 사양토와 양토 모두 70~120%의 적정 회수율을 나타내었으며, 상대표준편차도 20% 이내를 양호한 결과를 나타내었다. 따라서 QuEChERS 전처리 및 LC-MS를 이용한 분석법은 토양 중 잔류농약 다성분동시분석에 적용이 가능할 것으로 판단되었다.

• Journal of Microbiology and Biotechnology
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• 제19권1호
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• pp.51-54
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• 2009

Myxobacteria, Gram-negative soil bacteria, are a well-known producer of bioactive secondary metabolites. Therefore, this study presents a methodological approach for the high-throughput screening of secondary metabolites from 4 wild-type Myxococcus xanthus strains. First, electrospray ionization mass spectrometry (ESI-MS) was performed using extracellular crude extracts. As a result, 22 metabolite peaks were detected, and the metabolite profiling was then conducted using the m/z value, retention time, and MS/MS fragmentation pattern analyses. Among the peaks, one unknown compound peak was identified as analogous to the myxalamid A, B, and C series. An analysis of the tandem mass spectrometric fragmentation patterns and HR-MS identified myxalamid K as a new compound derived from M. xanthus. In conclusion, LC-MS/MS-based chemical screening of diverse secondary metabolites would appear to be an effective approach for discovering unknown microbial secondary metabolites.

• 한국고분자학회지:고분자과학과기술
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• 제22권2호
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• pp.188-193
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• 2011

• Mass Spectrometry Letters
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• 제9권1호
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• pp.17-23
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• 2018

Studies on the interactions of amyloidogenic proteins with trace metals, such as copper, have indicated that the metal ions perform a critical function in the early oligomerization process. Herein, we investigate the effects of Cu(II) ions on the active sequence regions of amyloidogenic proteins using electrospray ionization mass spectrometry (ESI-MS) and collision induced dissociation tandem MS (CID-MS/MS). We chose three amyloidogenic peptides NNQQNY, LYQLEN, and VQIVYK from yeast prion like protein Sup35, insulin chain A, and tau protein, respectively. [Cu-peptide] complexes for all three peptides were observed in the mass spectra. The mass spectra also show that increasing Cu(II) concentrations decrease the population of existing peptide oligomers. The tandem mass spectrum of NNQQNY shows preferential binding for the N-terminal region. All three peptides are likely to appear to be in a Cu-monomer-monomer (Cu-M-M) structure instead of a monomer-Cu-monomer (M-Cu-M) structure.

• Mass Spectrometry Letters
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• 제6권4호
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• pp.85-90
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• 2015

This article reviews recent analytical techniques using inductively coupled plasma-mass spectrometry (ICP-MS) immunoassay for clinical and bio analysis. We classified the techniques into two categories, direct and indirect analysis, which depend upon a guideline of whether tagging materials are used or not. Direct analysis is well known, and generally used in conjunction with various other techniques, such as laser ablation, chromatographic separations, etc. Recently, indirect analysis using tagging elements has intensively been discussed because of its importance in future applications to bio and clinical analysis, including environmental and food industries. The method has shown advantages of multiplex detection, excellent sensitivity, and short analysis time owing to signal amplification and magnetic separation. Now, it expands the application field from small biomolecules to large cells.

• 한국연초학회지
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• 제31권2호
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• pp.95-106
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• 2009

Semiquantitative analysis by ICP-MS has proven to be a powerful tool for fast screening, in addition, it does not require the element of interest to be present in the calibration standard, making it especially useful for the analysis of unknown samples. In this study, seven cigarette samples were analyzed by the rapid semi-quantitative analysis method based on the ICP-MS. For each cigarette sample, cut tobacco, cigarette paper, filter (before and after smoking), and smoke condensate were analyzed. The accuracy of the analysis technique was evaluated by comparing results obtained from Calibration Check Standard(CCS) and calibration method. Relative Percentage Error(RPE) value of all elements measured for three CCS showed a stable result of less than ${\pm}20%$. Compared to full quantitative analysis by calibration method, the results for cigarette samples showed average error within ${\pm}15%$.

• 분석과학
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• 제34권1호
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• pp.23-35
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• 2021

In order to measure the volatile organic compounds (VOCs) of a sample which is too large to use commercially available chamber, a stainless steel vacuum chamber (VC) (with an internal diameter of 205 mm and a height of 50 mm) was manufactured and the temperature of the chamber was controlled using an oven. After concentrating the volatiles of the sample in the chamber by helium gas, it was made possible to remove residual volatile substances present in the chamber under reduced pressure ((2 ± 1) × 10-2 mmHg). The chamber was connected to a purge & trap (P&T) using a 6 port valve to concentrate the VOCs, which were analyzed by gas chromatography-mass spectrometry (GC-MS) after thermal desorption (VC-P&T-GC-MS). Using toluene, the toluene recovery rate of this device was 85 ± 2 %, reproducibility was 5 ± 2 %, and the detection limit was 0.01 ng L-1. The method of removing VOCs remaining in the chamber with helium and the method of removing those with reduced pressure was compared using Korean drinking water regulation (KDWR) VOC Mix A (5 μL of 100 ㎍ mL-1) and butylated hydroxytoluene (BHT, 2 μL of 500 ㎍ mL-1). In case of using helium, which requires a large amount of gas and time, reduced pressure ((2 ± 1) × 10-2 mmHg) only during the GC-MS running time, could remove VOCs and BHT to less than 0.1 % of the original injection concentration. As a result of analyzing volatile substances using VC-P&T-GC-MS of six types of cell phone case, BHT was detected in four types and quantitatively analyzed. Maintaining the chamber at reduced pressure during the GC-MS analysis time eliminated memory effect and did not affect the next sample analysis. The volatile substances in a cell phone case were also analyzed by dynamic headspace (HT3) and GC-MS, and the results of the analysis were compared with those of VC-P&T-GC-MS. Considering the chamber volume and sample weight, the VC-P&T configuration was able to collect volatile substances more efficiently than the HT3. The VC-P&T-GC-MS system is believed to be useful for VOCs measurement of inhomogeneous large sample or devices used inside clean rooms.

• 한국식품위생안전성학회지
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• 제32권3호
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• pp.193-198
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• 2017

본 연구는 건강기능식품 중 baicalin, eleutheroside E, ligustilide를 효과적으로 분석할 수 있는 방법을 확립하기 위하여 수행되었다. 이에 LC-MS/MS를 이용하여 신속하고 효율적으로 동시분석할 수 있는 시험법을 확립하였으며, 확립된 시험법에 대해 특이성, 검출한계, 정량한계, 정확도, 정밀도에 대한 검증을 통하여 유효성을 확인하고자 하였다. 표준용액을 이용하여 검량선을 작성한 결과 $r^2$ > 0.99 이상의 직선성을 확인하였고, baicalin, eleutheroside E, ligustilide에 대한 정량한계는 각각 $39.3{\mu}g/L$, $106.7{\mu}g/L$, $76.1{\mu}g/L$이었으며, 검출한계는 각각 $13.0{\mu}g/L$, $35.2{\mu}g/L$, $25.1{\mu}g/L$이었다. 또한 평균 회수율은 각 성분에 대해 108.0~109.9%, 99.8~101.3%, 91.4~97.2%로 나타났으며, 반복정밀도는 상대표준편차 5%이하, 실험실간 재현성은 9%이하로 나타나 정확성, 재현성이 우수하였으며 이는 AOAC 가이드라인에서 제시한 기준에 모두 적합한 수준이었다. 따라서 개발된 분석법은 향후 건강기능식품 중 baicalin, eleutheroside E, ligustilide를 동시분석하는데 효과적으로 활용할 수 있을 것으로 판단된다.

• 분석과학
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• 제24권4호
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• pp.256-265
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• 2011

호박유물의 적절한 보존방안 마련에 필요한 호박의 화학적 분광학적 특성을 Infrared (IR) 분석과 pyrolysis/GC/MS (py/GC/MS) 분석을 통해 조사하였다. 호박 시료는 Baltic, Chiapas, Colombian, Dominican, Fushun, Madagascar 호박 등 6개의 산지에서 총 14종을 확보하였다. 시료의 비파괴적 조사를 위해 IR 분석을 실시하였고, 고분자 구성 성분 조사를 위해 py/GC/MS를 $300^{\circ}C$ 열분해 온도에서 온라인 trimethylsilylation을 통하여 분석하였다. IR 분석에서는 대체적으로 산지에 관계없이 유사한 스펙트럼을 보였으나, 지문영역에서는 Baltic 호박의 경우 Baltic shoulder에 해당하는 $1250cm^{-1}{\sim}1150cm^{-1}$에서 흡수가 나타나는 등 각각의 산지별로 구분이 가능한 차별화된 IR 스펙트럼이 관찰되었다. py/GC/MS 분석에서는 succinic acid, pimaric acid 등 호박의 구성성분으로 알려진 물질들이 검출되었고, Baltic, Chiapas, Fushun 호박의 경우 산지 구분이 가능한 특정성분이 검출되었다. 이러한 결과는 발견 및 발굴 유물에서 호박을 확인하거나, 산지 및 제작기술 추정 등 고고과학적인 해석의 기초 자료로 활용될 수 있을 것으로 기대된다.

• 한국환경보건학회지
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• 제38권6호
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• pp.561-567
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• 2012

Objectives: Parabens are widely used as antimicrobial agents in pharmaceuticals and cosmetics as well as by the food industry. Parabens have been reported to show weak estrogenic activity and be related to health effects such as allergic reactions and skin and breast cancer. We evaluated an online solid phase extraction (SPE) method coupled with LC-MS/MS technique using free and conjugated parent parabens in human urine for assessing human exposure to parabens. Methods: We employed LC/MS/MS through online solid phase extraction and column-switching techniques and analyzed free and conjugated parabens as biomarkers of human exposure. Four major parabens, methyl-paraben (MP), ethyl-paraben (EP), propyl-paraben (PP) and butyl-paraben (BP), were analyzed. Method validation was performed by sensitivity, accuracy, precision and comparison of the results of online SPE with offline SPE. Results: The limits of detection (LOD) were in the range of 0.2-2 ng/mL, and actual limits of quantification (LOQ) were in the range of 0.7-6 ng/mL urine, depending upon the compound. Accuracy was in the range of 98.3-106.4%, and precision was in the range of 1.3-8.7% (CV) depending upon the compound. We found a good correlation between the results of analysis by online SPE method and that by off-line SPE method. Conclusions: The online SPE method showed proper LOD and validated accuracy, precision and good correlation with the offline method for analyzing parabens in urine.