• Mass Spectrometry Letters
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• 제7권1호
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• pp.26-29
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• 2016

Simultaneous determination of three corticosteroids (clobetasol propionate, betamethasone dipropionate, fluticasone propionate) in moisturizers was performed by using liquid chromatography (LC) coupled with tandem mass spectrometry (MS/MS). Sample preparation was conducted by the liquid-liquid extraction (LLE). Moisturizers include emulsifying agent and it forms micelles. In order to improve the extraction efficiency of corticosteroids trapped in micelle, newly developed-optimized extraction conditions which can remove the matrix effect from moisturizers was applied with various pH conditions in LLE extraction stage of sample preparation. Thus, the addition of 10 μL of 1 M HCl into moisturizers sample before extraction could improve the extraction efficiency. For the quantitative analysis, SRM table that contained specific transition of all of target corticosteroids was created. The developed method was validated for linearity, accuracy, precision, limit of detection (LOD), limit of quantization (LOQ) and recovery. Over the 0.99 r² value was obtained in calibration standard range. Effective accuracy and precision were also obtained. LODs were below 31 ng/mL and LOQs were estimated below 94 ng/mL for all corticosteroids tested.

• 분석과학
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• 제16권1호
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• pp.82-89
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• 2003

Isotope dilution mass spectrometry (IDMS) was applied to the determination of Ni, Cr, Mo in low alloy steel reference materials. The Mo isotope ratio measurement was performed by dynamic reaction cell inductively coupled plasma mass spectrometry (DRC-ICP/MS) using ammonia as a reaction cell gas. In the case of Ni and Cr measurement, all data were obtained at medium resolution mode (m/${\Delta}m=3000$) of double focusing sector field high resolution inductively coupled plasma mass spectrometry (HR-ICP/MS). For the method validation of the technique was assessed using the certified reference materials such as NIST SRM 361, NIST SRM 362, NIST SRM 363, NIST SRM 364, NIST SRM 36b. This method was applied to the determination of Ni, Cr and Mo in low alloy steel sample (CCQM-P25) provided by NMIJ for international comparison study.

• Mass Spectrometry Letters
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• 제12권2호
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• pp.31-40
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• 2021

Probable human carcinogenic compounds nitrosamines, have been detected as by-product impurities in sartan pharmaceuticals in recent years which has drawn worries for medication safety. To provide a sensitive and effective method for the quality control of sartan pharmaceuticals, this study established a feasible gas chromatography-tandem mass spectrometry (GC-MS/MS) method for simultaneous determination of 13 nitrosamines. The target analytes were separated on a DB-WAX Ultra Inert column (30 m × 0.25 mm; i.d., 0.25 ㎛) and were then subjected to electron impact ionization in multiple reaction monitoring mode. The established method was validated and further employed to analyze authentic samples. Limits of detection (LODs) and limits of quantification (LOQs) of the 13 nitrosamines were 15-250 ng/g and 50-250 ng/g, respectively, which also exhibited intra-day and inter-day accuracies of 91.4-104.8%, thereby satisfying validation criteria. Five nitrosamines, viz., N-nitrosodiethylamine, N-nitrosodimethylamine, N-nitrosodiphenylamine, N-nitrosomorpholine, and N-nitrosopiperidine were detected at concentrations above their LODs in 68 positive samples out of 594 authentic samples from seven sartans.

• Mass Spectrometry Letters
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• 제15권3호
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• pp.149-157
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• 2024

The objective of the present study was to validate the analytical procedure for the quantitative determination of four trace metals (As, Cd, Pb, and Hg) in extracted fish lipids using Inductively Coupled Plasma-Mass Spectrometry, ICP-MS. The extracted lipids using Bligh and Dyer method were digested by means of microwave-assisted acid digestion and introduced into an optimized ICP-MS instrument. The validation of the analytical method was carried out in accordance with the international standards and guidelines outlined in the European Pharmacopeia (2022), which included specificity, selectivity, linearity, limit of detection, limit of quantification, precision, and accuracy. The linearity ranges of the calibration curves were R² > 0.999, while the relative standard deviation (%RSD) for precision was within 5%. All targeted trace metals have shown mean recoveries between 88.0%-114.9%. The obtained LOD and LOQ values for this analytical protocol indicated the ability to detect and quantify of As, Cd, Pb, and Hg at trace levels. The overall validation confirms the described analytical method was appropriate for routine analyses of As, Cd, Pb, and Hg in fish lipids.

• Mass Spectrometry Letters
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• 제15권3호
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• pp.158-165
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• 2024

Pneumonia is an acute respiratory infection that primarily affects the lungs and is caused by various microorganisms, including viruses, fungi, and bacteria. Klebsiella pneumoniae, a multidrug-resistant (MDR) and extensively drug-resistant (XDR) bacterium, is a leading cause of widespread pneumonia. This study aimed to identify endophytic bacteria from the leaves of Acalypha indica L. and evaluate their antibacterial properties through both in vitro and in silico approaches. The objectives included isolating endophytic bacteria from Acalypha indica L., testing their antibacterial activity against Klebsiella pneumoniae, identifying the selected bacterial isolates using molecular techniques, analyzing their secondary metabolites via gas chromatography-mass spectrometry (GC-MS), and performing in silico molecular docking studies. The study identified BE 4, an endophytic bacterial isolate of Bacillus pumilus, as exhibiting the most potent antibacterial activity against Klebsiella pneumoniae. GC-MS analysis of the ethyl acetate extract of this isolate revealed 1,2-benzenedicarboxylic acid, bis(2-methylpropyl) ester as the primary metabolite component. Furthermore, molecular docking analysis identified two natural compound ligands, 1,2-benzenedicarboxylic acid, diethyl ester (-6.5 kcal/mol), and lilial (-6.2 kcal/mol), as having potential efficacy against drugresistant bacteria responsible for pneumonia. These findings suggest that endophytic bacteria and their bioactive compounds could serve as promising candidates for the development of new treatments against drug-resistant pneumonia.

• Food Science and Biotechnology
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• 제17권3호
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• pp.508-513
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• 2008

Erythromycin has been used to treat Streptococosis, Edwardsiel1osis, Vibriosis, Bacterial enteritis in the cultured fish. In this study, a rapid and effective erythromycin analysis method with new sample treatment protocol and liquid chromatography/tandem mass spectrometry (LC/MS/MS) system for fish products was developed. For the erythromycin extraction from fish muscle, the solvent mixture composed of 0.2% meta-phosphoric acid and methanol (6:4) showed good recovery rate, and the optimum extraction solvent volume was 20 mL. Erythromycin detection using LC/MS/MS were carried out under electro spray ionization (ESI) positive condition and erythromycin mass value 576.2 and 157.9. And the detection limit of the established method was 0.005 mg/kg in fish products. The recovery rate of the developed method applied to the fish species were as following, olive flounder, $87.6{\pm}5.0%$; black rockfish, $87.2{\pm}6.4%$; eel, $85.2{\pm}4.8%$; and rainbow trout, $86.0{\pm}6.2%$. In the established method in this study, the correlation of coefficient values ($R^2$) of erythromycin calibration curve (n=11) was 0.9998.

• Mass Spectrometry Letters
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• 제11권4호
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• pp.82-89
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• 2020

A systematic isolation and characterization study for Cassia auriculata (CA) seeds resulted in identifying antidiabetic compounds 1,3,8-trihydroxyanthraquinone and quercetin, quercetin-3-O-rutinoside, gallic acid, caffeic acid, ferulic acid, and ellagic acid. The ultra-high-performance liquid chromatography based triple quadrupole mass spectrometry methodology was developed and validated for simultaneous identification and confirmation of these compounds from CA seeds. Multiple reaction monitoring (MRM) based quantification method was developed with MRM optimizer software for MS1 and MS2 mass analysis. The method was optimized on precursor ions and product ions with the ion ratio of each compound. The calibration curves of seven bioactive analytes showed excellent linearity (r2 ≥ 0.99). The quantitation results found precise (RSD, < 10 %) with good recoveries (84.58 to 101.42%). The matrix effect and extraction recoveries were found within the range (91.66 to 102.11%) for the CA seeds. This is the first MS/MS-based methodology applied to quantifying seven antidiabetic compounds in CA seeds and its extract for quality control purposes.

• Journal of Applied Biological Chemistry
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• 제58권2호
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• pp.175-181
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• 2015

제주에서 생산된 페퍼민트, 스피아민트, 오데코롱민트 3종으로 부터 추출한 에센셜오일의 성분을 기체 크로마토그래피-질량분석기(GC-MS)와 headspace-GC-MS (HS-GC-MS)를 이용하여 분석하였다. GC-MS 분석결과 페퍼민트, 스피아민트, 오데코롱민트 각각에서 13종의 성분이 동정되었다. 전체 이온 크로마토그램의 피크 intensity를 기초로 보았을 때, 페퍼민트에서는 peperitenone oxide, 스피아민트에서는 carvone과 limonene, 오데코롱민트에서는 linalool이 주 화합물로 동정되었다. HS-GC-MS 분석에서는 GC-MS와 비교하였을 때 alcohol과 acetate와 같은 휘발성이 강한 성분이 많이 검출되었고, 검출되는 성분의 수도 증가하였다. 하지만 스피아민트와 오데코롱민트의 주 화합물은 GC-MS에서 검출된 것과 같았고, 페퍼민트에서만 GC-MS에서 낮은 함량을 보였던 menthol이 주요화합물로 동정되었다. 흥미롭게도, 오데코롱민트 에센셜 오일에서 linalyl acetate와 linalool의 함량이 탁월하게 높음을 확인했다.

• Mass Spectrometry Letters
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• 제15권1호
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• pp.1-25
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• 2024

Protein glycosylation, a highly significant and ubiquitous post-translational modification (PTM) in eukaryotic cells, has attracted considerable research interest due to its pivotal role in a wide array of essential biological processes. Conducting a comprehensive analysis of glycoproteins is imperative for understanding glycoprotein bio-functions and identifying glycosylated biomarkers. However, the complexity and heterogeneity of glycan structures, coupled with the low abundance and poor ionization efficiencies of glycopeptides have all contributed to making the analysis and subsequent identification of glycans and glycopeptides much more challenging than any other biopolymers. Nevertheless, the significant advancements in enrichment techniques, chromatographic separation, and mass spectrometric methodologies represent promising avenues for mitigating these challenges. Numerous substrates and multifunctional materials are being designed for glycopeptide enrichment, proving valuable in glycomics and glycoproteomics. Mass spectrometry (MS) is pivotal for probing protein glycosylation, offering sensitivity and structural insight into glycopeptides and glycans. Additionally, enhanced MS-based glycopeptide characterization employs various separation techniques like liquid chromatography, capillary electrophoresis, and ion mobility. In this review, we highlight recent advances in enrichment methods and MS-based separation techniques for analyzing different types of protein glycosylation. This review also discusses various approaches employed for glycan release that facilitate the investigation of the glycosylation sites of the identified glycoproteins. Furthermore, numerous bioinformatics tools aiding in accurately characterizing glycan and glycopeptides are covered.

• Bulletin of the Korean Chemical Society
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• 제26권9호
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• pp.1347-1353
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• 2005

Sets of sialic acid-containing trisaccharides having different internal and terminal linkages have been synthesized to develop a sensitive method for analysis of the reducing terminal linkage positions. The trisaccharides, sialyl($\alpha$ 2-3)Gal($\beta$ 1-3)GalNAc and sialyl($\alpha$ 2-3)Gal($\beta$ 1-X)GlcNAc where X=3, 4 and 6, were synthesized and examined using electrospray ionization (ESI)-collision induced dissociation (CID) tandem mass spectrometry (MS/MS). The compounds chosen for this study are related to terminal groups likely to be found on polylactosamine-like glycoproteins and glycolipids which occur on the surface of mammalian cells. The purpose of this study is to develop tandem mass spectrometral methods to determine detailed carbohydrate structures on permethylated or partially methylated oligosaccharides for future applications on biologically active glycoconjugates and to exploit a faster method of synthesizing a series of structural isomeric oligosaccharides to be used for further mass spectrometry and instrumental analysis.