• Bulletin of the Korean Chemical Society
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• 제31권11호
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• pp.3151-3155
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• 2010

This study was performed to develop analytical methods to better understand the properties and reactivity of petroleum, which is a highly complex organic mixture, using high-resolution mass spectrometry and statistical analysis. Ten crude oil samples were analyzed using negative-mode electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS). Clustering methods, including principle component analysis (PCA), hierarchical clustering analysis (HCA), and k-means clustering, were used to comparatively interpret the spectra. All the methods were consistent and showed that oxygen and sulfur-containing heteroatom species played important roles in clustering samples or peaks. The oxygen-containing samples had higher acidity than the other samples, and the clustering results were linked to properties of the crude oils. This study demonstrated that clustering methods provide a simple and effective way to interpret complex petroleomic data.

• 농업과학연구
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• 제43권4호
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• pp.634-640
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• 2016

The objective of this study was to evaluate the effectiveness of using HR-GC/MS for the rapid screening of dieldrin residues in soils. Persistent organic pollutants (POPs) of organochlorine pesticides such as dieldrin, were analyzed in sedimentary rock and granite rock collected from greenhouses, Niigata, Japan. Dieldrin remains in Japanese farming soils, more than 40 years after their use as insecticides was prohibited. The averages in soil moisture ranged from 2.79% to 7.20% in soils derived from sedimentary rock and from 25.59% to 31.40% in soils derived from granite rock. Mean concentrations of dieldrin residues in sedimentary rock and granite rock were $39.7ng\;g^{-1}$ and $40.51ng\;g^{-1}$, respectively. Dieldrin residue was detected at a slightly higher concentration in granite rock than sedimentary rock samples. There was no consistency between the two soils or between surface and subsurface soils. The coefficients of variation of the two soils were 10.6% and 8.7%, respectively. These results suggest that our high-resolution mass spectrometry detector (HR-GC/MS) is effective at analyzing residual organochlorine pesticides in soil. In order to increase the precision and sensitivity for chemical analysis of POPs, high-resolution gas chromatography coupled with a HR-GC/MS is highly recommended.

• Bulletin of the Korean Chemical Society
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• 제32권4호
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• pp.1170-1178
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• 2011

In the present study, the approach of high accuracy mass measurements for phospholipid identifications was evaluated using a 7 T ESI-FTMS/linear ion trap MS/MS. Experiments were carried out for porcine brain, bovine liver, and soybean total lipid extracts in both positive and negative ion modes. In total, 59, 55, and 18 phospholipid species were characterized in the positive ion mode for porcine brain, bovine liver, and soybean lipid extracts, respectively. Assigned lipid classes were PC, PE, PEt, PS, and SM. In the negative ion mode, PG, PS, PA, PE, and PI classes were observed. In the negative ion mode, for porcine brain, bovine liver, and soybean lipid extracts, 28, 34, and 29 species were characterized, respectively. Comparison of our results with those obtained by other groups using derivatization-LC-APCI MS and nano-RP-LC-MS/MS showed that our approach can characterize PC species as effectively as those methods could. In conclusion, we demonstrated that high accuracy mass measurements of total lipid extracts using a high resolution FTMS, particularly, 7T FTMS, plus ion-trap MS/MS are very useful in profiling lipid compositions in biological samples.

• Bulletin of the Korean Chemical Society
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• 제25권4호
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• pp.447-451
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• 2004

Low and high resolution inductively coupled plasma mass spectrometry (ICP-MS) coupled with ion chromatography (IC) has been investigated for speciation of Cr(III) and Cr(VI). In particular, the interference of ArC^+formed by the carbon in a sample on the simultaneous determination of Cr(III) and Cr(VI) has been studied. In chemical speciation, this study shows that quadrupole type ICP-MS with low resolution has a limitation of simultaneous determination fo chromium species if the sample contains the carbon elements. The interference problems can be solved by high resolution ICP-MS.

• Animal Bioscience
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• 제37권5호
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• pp.918-928
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• 2024

Objective: The adulteration of raw beef (BMr) with dog meat (DMr) and pork (PMr) becomes a serious problem because it is associated with halal status, quality, and safety of meats. This research aimed to develop an effective authentication method to detect non-halal meats (dog meat and pork) in beef using metabolomics approach. Methods: Liquid chromatography-high resolution mass spectrometry (LC-HRMS) using untargeted approach combined with chemometrics was applied for analysis non-halal meats in BMr. Results: The untargeted metabolomics approach successfully identified various metabolites in BMr DMr, PMr, and their mixtures. The discrimination and classification between authentic BMr and those adulterated with DMr and PMr were successfully determined using partial least square-discriminant analysis (PLS-DA) with high accuracy. All BMr samples containing non-halal meats could be differentiated from authentic BMr. A number of discriminating metabolites with potential as biomarkers to discriminate BMr in the mixtures with DMr and PMr could be identified from the analysis of variable importance for projection value. Partial least square (PLS) and orthogonal PLS (OPLS) regression using discriminating metabolites showed high accuracy (R² >0.990) and high precision (both RMSEC and RMSEE <5%) in predicting the concentration of DMr and PMr present in beef indicating that the discriminating metabolites were good predictors. The developed untargeted LC-HRMS metabolomics and chemometrics successfully identified non-halal meats adulteration (DMr and PMr) in beef with high sensitivity up to 0.1% (w/w). Conclusion: A combination of LC-HRMS untargeted metabolomic and chemometrics promises to be an effective analytical technique for halal authenticity testing of meats. This method could be further standardized and proposed as a method for halal authentication of meats.

• Bulletin of the Korean Chemical Society
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• 제35권3호
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• pp.709-714
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• 2014

Protein tyrosine nitration is considered as an important indicator of nitrosative stresses and as one of the main factors for pathogenesis of inflammation and neuronal degeneration. In this study, we investigated various nitrosative modifications of bovine carbonic anhydrase II (CAII) through qualitative and semi-quantitative analysis using the combined strategy of Fourier transformation ion cyclotron resonance mass spectrometry (FT-ICR MS) and ion-trap tandem mass spectrometry (IT-MS/MS). FT-ICR MS and its spectra were used for the search of the pattern of nitrosative modifications. Identification of nitrosatively modified tyrosine sites were executed through IT-MS/MS. In addition, we also tried to infer the reason for the site-specific nitrosative modifications in CAII. In view of the above purpose, we have explored- i) the side chain accessibility, ii) the electrostatic environment originated from the acidic/basic amino acid residues neighboring to the nitrosatively modified site and iii) the existence of competing amino acid residues for nitration.

• Bulletin of the Korean Chemical Society
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• 제34권9호
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• pp.2635-2639
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• 2013

The rapid and accurate identification of biological agents is a critical step in the case of bio-terror and biological warfare attacks. Recently, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry has been widely used for the identification of microorganisms. In this study, we describe a method for the rapid and accurate discrimination of Bacillus anthracis spores using MALDI-TOF MS. Our direct in-situ analysis of MALDI-TOF MS does not involve subsequent high-resolution mass analyses and sample preparation steps. This method allowed the detection of species-specific biomarkers from each Bacillus spores. Especially, B. anthracis spores had specific biomarker peaks at 2503, 3089, 3376, 6684, 6698, 6753, and 6840 m/z. Cluster and PCA analyses of the mass spectra of Bacillus spores revealed distinctively separated clusters and within-groups similarity. Therefore, we believe that this method is effective in the real-time identification of biological warfare agents such as B. anthracis as well as other microorganisms in the field.

• Bulletin of the Korean Chemical Society
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• 제19권6호
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• pp.617-618
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• 1998

A simple and reproducible pretreatment method was developed for the determination of dioxins in milk sample. Liquid-liquid extraction (LLE) was used for the initial extraction of the analyte from milk. For the elimination of interferences coextracted from milk, acid treatment followed by multilayer silica gel, and then alumina column clean-up were performed. The clean extract could be obtained without carbon column or high performance liquid chromatographic (HPLC) clean-up procedure. Polychlorinated biphenyles (PCBs) and dioxins were separated on neutral alumina activated at 180 ℃ for 12 hours. The final extract was analyzed by HPLC and high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS). The recovery of dioxins spiked in milk at 75-300 ppt level was 83.3-98.9% and their relative standard deviation was 4.1-14%.

• Bulletin of the Korean Chemical Society
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• 제19권6호
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• pp.619-624
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• 1998

A simple and reproducible pretreatment method was developed for the determination of dioxins in milk sample. Liquid-liquid extraction (LLE) was used for the initial extraction of the analyte from milk. For the elimination of interferences coextracted from milk, acid treatment followed by multilayer silica gel, and then alumina column clean-up were performed. The clean extract could be obtained without carbon column or high performance liquid chromatographic (HPLC) clean-up procedure. Polychlorinated biphenyles (PCBS) and dioxins were separated on neutral alumina activated at 180 ℃ for 12 hours. The final extract was analyzed by HPLC and high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS). The recovery of dioxins spiked in milk at 75-300 ppt level was 83.3-98.9% and their relative standard deviation was 4.1-14%.

• 분석과학
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• 제21권4호
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• pp.245-258
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• 2008

본 연구에서는 하고초의 지표성분인 triterpenic acids 5종을 컬럼 크로마토그래피와 역상 HPLC를 이용하여 추출 및 분리했고, 이들 성분의 순도는 90% 이상임을 HPLC를 이용하여 확인했다. 고속원자충돌 이온화법-고분해능 질량분석기(FAB-HRMS)를 사용하여 지표성분의 분자량 및 원소조성을 결정했으며, 지표성분의 구조 분석은 FAB-MS/MS 의해 음이온 및 양이온 모드에서 수행하였다. Triterpenic acid류의 충돌유발분해(collision-induced dissociation, CID) 탄뎀질량분석(MS/MS) 스펙트럼에서 protonated molecule인 $[M+H]^+$ 및 deprotonated molecule인 $[M-H]^-$ 이온의 CID는 주로 retro Diels-Alder (RDA), 탈수 (dehydration) 및 탈탄산(decarboxylation) 반응에 의한 다양한 생성이온들이 나타났다. 특히, $[M-H]^-$이온의 CID-MS/MS 스펙트럼에서는 charge-remote fragmentation (CRF) 현상에 의한 이온들도 특성이온으로 나타났다. 이들 CID-MS/MS 스펙트럼의 해석을 통하여 하고초의 지표성분인 triterpenic acids의 구조 규명을 수행하였다.