• Bulletin of the Korean Chemical Society
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• 제28권5호
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• pp.737-744
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• 2007

An isotope dilution-liquid chromatography/tandem mass spectrometric method was developed as a candidate reference method for the accurate determination of acrylamide in potato chips, starch-rich foodstuff cooked at high temperature. Sample was spiked with 13C3-acrylamide and then extracted with water. The extract was further cleaned up with an Oasis HLB solid-phase extraction (SPE) cartridge and an Oasis mixed-phase cation exchange (MCX) SPE cartridge. The extract was analyzed by using LC/ESI/Tandem MS in positive ion mode. LC with a medium reversed-phase (C4) column was optimized to obtain adequate chromatographic retention and separation of acrylamide. MS was operated to selectively monitor [M+H]+ ions of the analyte and its isotope analogue at m/z 72 and m/z 75, respectively. Sample was also analyzed by the LC/MS with selectively monitoring the collisionally induced dissociation channels of m/z 72 → m/z 55 and m/z 75 → 58. Compared to the LC/MS chromatograms, the LC/MS/MS chromatograms showed substantially reduced background chemical noises coming from solvent clusters formed during ESI spray processes and interferences from sample matrix. Repeatability and reproducibility studies showed that the LC/MS/MS method is a reliable and reproducible method which can provide a typical method precision of 1.0% while the LC/MS results are influenced by chemical interferences.

• 한국축산식품학회지
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• 제34권5호
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• pp.656-664
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• 2014

The purpose of this study was to analyze myosin heavy chain (MHC) isoforms in bovine longissimus thoracis (LT) muscle by liquid chromatography (LC) and mass spectrometry (MS). LT muscles taken from Hanwoo (Korean native cattle) steer (n=3) used to separate myosin bands by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The peptide queries were obtained from the myosin bands by LC-MS/MS analysis following in-gel digestion with trypsin. A total of 33 and 43 queries were identified as common and unique peptides, respectively, of MHC isoforms (individual ions scores >43 indicate identity or extensive homology, p<0.05). MHC-1 (IIx), -2 (IIa), -4 (IIb), and -7 (slow/I) were identified based on the Mowse score (5118, 3951, 2526, and 2541 for MHC-1, -2, -4, and -7, respectively). However, more analysis is needed to confirm the expression of MHC-4 in bovine LT muscle because any query identified as a unique peptide of MHC-4 was not found. The queries that were identified as unique peptides could be used as peptide markers to confirm MHC-1 (14 queries), -2 (8 queries), and -7 (21 queries) in bovine LT muscle; no query identified as a unique peptide of MHC-4 was found. LC-MS/MS analysis is a useful approach to study MHC isoforms at the protein level.

• 분석과학
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• 제23권1호
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• pp.54-59
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• 2010

액체크로마토그래피/질량분석법(LC/MS)을 이용하여 화장품에 들어있는 파라벤류등을 동시 분석하였다. 화장품 시료를 메탄올에 직접 용해시키고 $0.45\;{\mu}m$ 필터로 여과하여 메탄올/물을 이동상으로 하여 Extend $C_{18}$의 비극성 컬럼을 사용하여 기울기 용리 조건에서 12분 안에 분리하여 SIM(selected ion monitoring)방법으로 정량하였다. LC/MS 분석결과 검량선은 $0.05-10\;{\mu}g$/mL 농도범위에서 $r^2$=0.9993의 상관계수를 갖는 좋은 직선성을 나타내었으며, 검출한계는 $0.01\;{\mu}g$/mL 이었다.

• 대한한방부인과학회지
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• 제26권4호
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• pp.48-65
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• 2013

Objectives: We took breast milk samples and analyzed them using HPLC and LC/MS/MS, to evaluate the effects of taking Saenghwa-tang during breastfeeding on breast milk. Methods: The study participants were 20 lactating women who admitted in Korean medical postpartum care center. Breast milks were collected from paticipants who have been administrated Saenghwa-tang for more than 3 days. We used HPLC and LC/MS/MS for the determinations of amygdalin, liquiritins, 6-gingerol, decursin and decursinol angelate in Saenghwa-tang. Results: 1. Participants' $Mean{\pm}S.D$ (standard deviation) of age is $31.05{\pm}1.96$, and 15 participants had normal delivery and 5 participants had cesarean delivery. 12 participants were primipara and 8 participants were multipara. $Mean{\pm}S.D$ of lactating date is $9.4{\pm}0.94$. 2. Using HPLC, we learned LOQ level peak that matches the peak retention time of standard components of Saenghwa-tang was not detected from 20 breast milk samples. 3. Using LC/MS/MS, decursin of Angelicae Gigantis Radix was detected from HMSP 02, HMSP 04, HMSP 06, HMSP 11, and the each concentrations are 16, 2, 64, 11 ppb. Liquiritin of Glycyrrhizae Radix was not detected from HMSP 13~HMSP 18. Conclusions: Data obtained by this approach shows that this method is reliable and suitable for determining the safety of taking Saenghwa-tang during breastfeeding.

• 생약학회지
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• 제47권4호
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• pp.381-388
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• 2016

Hyangso-san is a traditional herbal medicine that consists of the seven herbal medicines, Cyperi Rhizoma, Perillae Folium, Atractylodis Rhizoma, Citri Unshius Pericarpium, Glycyrrhizae Radix et Rhizoma, Zingiberis Rhizoma Crudus, and Allii Fistulosi Bulbus. Hyangso-san has long been clinically used to treat the influenza, including headache, ferver, chills, and pantalgia. In this study, we were performed the simultaneous analysis of the 15 marker compounds (liquiritin apioside, liquiritin, ferulic acid, naringin, hesperidin, rosmarinic acid, liquiritigenin, kaempferol, glycyrrhizin, nobiletin, 6-gingerol, elemicin, atractylenolide III, nootkatone, and atractylenolide I) in Hyangso-san using liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS/MS). Column for the separation of the 15 ingredients was used a Waters Acquity UPLC BEH $C_{18}$ analytical column ($2.1{\times}100mm$, $1.7{\mu}m$) at $45^{\circ}C$ by using a mobile phase of 0.1% (v/v) formic acid in water and acetonitrile with gradient condition. Identifications of all analytes were performed using a Waters ACQUITY TQD LC-MS/MS system. The flow rate and injection volume were 0.3 mL/min and $2.0{\mu}L$, respectively. Correlation coefficient of the calibration curve was ${\geq}0.9958$. The values of limits of detection and quantification of the 15 components were 0.002-4.29 and 0.01-12.88 ng/mL, respectively. The result of an analysis using the established LC-MS/MS method, kaempferol and atractylenolide I were not detected, while other 13 compounds were 0.08-56.87 mg/g in lyophilized Hyangso-san sample.

• 한국수산과학회지
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• 제53권2호
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• pp.174-180
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• 2020

The mouse bioassay has been used widely for the monitoring of paralytic shellfish toxins (PSTs) in many countries. However, this method shows low sensitivity and high limit of detection (LOD), as well as it cannot confirm toxic profiles. Recently, LC-MS/MS method was studied for the quantitative of PSTs, however, the method has any problems with unstable retention times by ionization suppression caused by high salt concentration in shellfish extracts. To establish an alternative method for PSTs analysis, we tried to original LC-MS/MS methods adding desalting operation using amorphous graphitized polymer carbon solid-phase extraction cartridges. The method validation was conducted to determine linearity, limit of detection, limit of quantification (LOQ), accuracy, and precision in quantifying PSTs. The correlation coefficients for all tested PSTs maintained over 0.999. The LODs and LOQs for all PSTs were about 0.19-1.05 ㎍/kg and 0.58-3.18 ㎍/kg, respectively. The accuracies for PSTs were 95.4-107.7% for saxitoxin group, 97.1-100.9% for gonyautoxin group, 99.0-100.8% for N-sulfocarbamoyl toxin group, and 96.8-104.6% for decarbamoyl toxin group. These results indicate that the modified LC-MS/MS method was appropriate for analyzing the PSTs in shellfish and tunicates.

• 한국수산과학회지
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• 제46권2호
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• pp.154-159
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• 2013

The AOAC Mouse Bioassay method (MBA) has been widely used for routine monitoring of paralytic shellfish poisoning (PSP) for more than 50 years. However, this method has low sensitivity and experiences interference from other components in the extract. Also, ethical issues have been raised against the continued use of this live-mouse assay. To establish an alternative method for PSP analysis, we attempted to develop PSP analysis conditions using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The LC-MS/MS analysis of reference material showed very reasonable accuracy, and the analysis time was just 15 min. However, the recovery rate of toxin spike samples using the LC-MS/MS analysis was 59.4-91.0%. We also attempted to remove the matrix effect using shellfish extracts, but recoveries of C1 and C2 did not improve. A comparison between the results of MBA and LC-MS/MS analysis revealed good correlations, with values of 0.8878 and 0.9211 for oyster and mussel matrices, respectively.

• Mass Spectrometry Letters
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• 제6권4호
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• pp.105-111
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• 2015

Sixteen compounds of Neobalanocarpus heimii were successfully identified directly from their plant extract using a triple quadrupole LC-MS/MS system. In order to fulfil the objectives of this work, a series of stilbene oligomers of various degrees of condensation were isolated and their structure are characterized. Out of these, four are resveratrol dimers, three trimers, and nine tetramers. The isolation process was done on a fully automated semi-preparative HPLC system. Their structures were elucidated on the basis of 1D- and 2D-NMR as well as MS data. The mass fragmentation patterns of the compounds were recorded and a retrievable in-house library was built to keep the data. In order to demonstrate the potential of this approach, the polyphenolic crude extract was analysed with the LC-MS/MS system and the MS/MS spectra extracted for each chromatographic peak of interest. The fragmentation patterns were compared with those of anticipated pure compounds that were previously recorded. All compounds were successfully identified. It is therefore believed that the LC-MS/MS potential for dereplication of structurally similar compounds in a crude mixture was thus firmly established.

• 분석과학
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• 제30권2호
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• pp.102-111
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• 2017

Here we reported a methodology for identification of triacylglycerols (TAGs) and diacylglycerols (DAGs) in coix seed by preparative thin layer chromatography (prep-TLC) and non-aqueous reversed-phase liquid chromatography (NARP LC)-atmospheric pressure chemical ionization (APCI) tandem mass spectrometry (MS/MS). Lipid components were extracted from coix seed by reflux extraction using n-hexane for 3 hr. TAGs and DAGs in coix seed extract were effectively purified and isolated from matrix interferences by prep-TLC and then analyzed by LC-APCI-MS and MS/MS for identification. TAGs were effectively identified taking into consideration of their LC retention behavior, APCI-MS spectra patterns, and MS/MS spectra of $[DAG]^+$ ions. In MS/MS spectra of TAGs, diacylglycerol-like fragment $[DAG]^+$ ions were useful to identify TAGs with isobaric fragment ions. Based on an established method, 27 TAGs and 8 DAGs were identified in coix seed extract. Among them, 15 TAGs and 8 DAGs were for the first time observed in coix seed. Interestingly, some of TAGs isolated by prep-TLC were partly converted into DAGs through probably photolysis process during storing in room temperature. Thus, degradation phenomenon of TAGs should be considered in the quality evaluation and nutritional property of coix seed. LC-APCI-MS/MS combined with prep-TLC will be practical method for precise TAG and DAG analysis of other herbal plants.

• 분석과학
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• 제26권4호
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• pp.221-227
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• 2013

LC-MS/MS를 이용하여 인체 혈장 중 ginsenoside Rg1의 신속하고 정확한 분석법을 개발하고 이 분석법에 대한 검증을 수행하였다. 혈장 분석을 위하여 internal standard인 digoxin을 첨가한 후 acetone과 methanol용액 (80:20)으로 전처리하고, 그 상층액을 진공농축 한 후, LC-MS/MS로 분석하였다. 최적 크로마토그래피 분석은 0.1% formic acid 첨가된 water와 methanol을 이동상으로 하여 Agilent Eclipse XDB-C18 column ($4.6{\times}150mm$, $5{\mu}m$)을 이용하여 0.9 mL/min의 유속으로 gradient mode로 수행하였다. 혈장 중 ginsenoside Rg1의 표준 검량선은 1~500 ng/mL의 농도 범위에서 우수한 직선성($r^2=0.9995$)을 보였으며, 일내, 일간 정밀성은 변동계수 7.53% 이하, 정확성은 98.28% 이상이었다. 결과적으로 본 분석법은 ginsenoside Rg1의 약동학 연구에 적용되기에 충분한 감도와 특이성, 직선성, 정밀성 및 정확성을 가지고 있음을 확인하였다.