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  • P-ISSN2233-4203
  • E-ISSN2093-8950

Vol.9 No.4

Emily R. Sekera(State University of New York) ; Troy D. Wood(State University of New York) pp.91-94 https://doi.org/10.5478/MSL.2018.9.4.91
초록보기
Abstract

Bilin tetrapyrroles are metabolic products of the breakdown of porphyrins within a species. In the case of mammals, these bilins are formed by the catabolism of heme and can be utilized as either biomarkers in disease or as an indicator of human waste contamination. Although a small subset of bilin tandem mass spectrometry reports exist, limited data is available in online databases for their fragmentation. The use of fragmentation data is important for metabolomics analyses to determine the identity of compounds detected within a sample. Therefore, in this study, the fragmentation of bilins generated by positive ion mode electro- spray ionization is examined by collision-induced dissociation (CID) as a function of collision energy on an FT-ICR MS. The use of the FT-ICR MS allows for high mass accuracy measurements, and thus the formulas of resultant product ions can be ascertained. Based on our observations, fragmentation behavior for hemin, biliverdin and its dimethyl ester, phycocyanobilin, bilirubin, bilirubin conjugate, mesobilirubin, urobilin, and stercobilin are discussed in the context of the molecular structure and collision energy. This report provides insight into the identification of structures within this class of molecules for untargeted analyses.

Haejong Jang(Kangwon National University) ; Xuan Lan Mai(Kangwon National University) ; Gunhee Lee(Kangwon National University) ; Jae Hyoung Ahn(Kangwon National University) ; Jongsook Rhee(National Forensic Service Busan Institute) ; Quoc-Ky Truong(Pham Ngoc Thach University of Medicine) ; Dinh Vinh(University of Medicine and Pharmacy Ho Chi Minh City) ; Jongki Hong(Kyung Hee University) ; Kyeong Ho Kim(Kangwon National University) pp.95-99 https://doi.org/10.5478/MSL.2018.9.4.95
초록보기
Abstract

An innovative, simple, and rapid assay method based on liquid chromatography coupled with tandem mass spec- trometry (LC-MS/MS) was developed and validated for the simultaneous determination of eight statin drugs in human urine. A simple sample clean-up procedure using the “dilute and shoot” (DAS) approach enabled a fast and reliable analysis. The influ- ence of the dilution factor was investigated to ensure detectability and reduce the matrix effect. Chromatographic separation was performed on a Phenomenex Kinetex C18 column (50 × 3.0 mm i.d., 2.6 µm) using an elution gradient of mobile phase A com- posed of 0.1% acetic acid, and mobile phase B composed of acetonitrile, at a flow rate of 0.35 mL/min. Quantitation was per- formed on a triple quadrupole mass spectrometer operated in multiple reaction monitoring (MRM) mode using electrospray ionization in positive ion mode. The total chromatographic run time was 15 min. The method was validated for selectivity, sen- sitivity, recovery, linearity, accuracy, precision, and stability. The present method was successfully applied to the analysis of Rosuvastatin in urine samples after oral administration to healthy human subjects.

Ha Ra Cho(Dankook University) ; Dong Yoon Kim(Dankook University) ; Hyo Chun Lee(Dankook University) ; Sang Beom Han(Chung-Ang University) ; Ho-Chul Shin(Konkuk University) ; Yong Seok Choi(Dankook University) pp.100-104 https://doi.org/10.5478/MSL.2018.9.4.100
초록보기
Abstract

As a part of efforts to establish the positive list system (PLS) in South Korea, a method to determine residual ema- mectin benzoate (EB) in various aquatic products using QuEChERS-EDTA and LC-MRM was developed. The developed method was validated in the aspects of specificity, linearity (correlation coefficient of at least 0.996), sensitivity (the limit of detection and the lower limit of quantitation ≤ 5 ng/g), recovery (the recovery range of 87.4 and 96.2), and precision (the relative standard deviation of recovery between 0.9 and 13.5). Additionally, the validated method was successfully applied for monitor- ing EB contamination in eel, halibut, and shrimp collected from local food markets. To our knowledge, the present method is the first one to determine residual EB in various aquatic products at the level satisfying the PLS and could contribute to the estab- lishment of the PLS in South Korea.

Jong Wha Lee(Korea Research Institute of Standards and Science (KRISS)) ; Sung Woo Heo(Korea Research Institute of Standards and Science (KRISS)) ; Hwijin Kim(Korea Research Institute of Standards and Science (KRISS)) ; Youngran Lim(Korea Research Institute of Standards and Science (KRISS)) ; Kyoung-Seok Lee(Korea Research Institute of Standards and Science (KRISS)) ; Yong-Hyeon Yim(Korea Research Institute of Standards and Science (KRISS)) pp.105-109 https://doi.org/10.5478/MSL.2018.9.4.105
초록보기
Abstract

A certified reference material (CRM) for the analysis of inorganic nutrients in nutritional supplements has been developed. Accurate mass fractions of chromium (Cr), iron (Fe), copper (Cu), and zinc (Zn) were determined by isotope dilution inductively coupled plasma mass spectrometry (ID ICP/MS). The measurement results were used to assign certified values for the CRM, which were metrologically traceable to the definitions of the measurement units in the International System of Units (SI). Production of a candidate reference material (RM) and the certification processes are summarized. Each nutrient in the CRM showed good homogeneity, which was estimated using relative standard deviations of the measurement results of twelve bottles in a batch. This CRM is expected to be an important reference to improve reliability and comparability of nutrient analy- ses in nutritional supplements and related samples in analytical laboratories.

Yujin Lee(Hankuk University of Foreign Studies) ; Eunji Seo(Hankuk University of Foreign Studies) ; Jun Young Park(Hankuk University of Foreign Studies) ; Kwang-Hak Bae(Apple tree Dental Hospital) ; Jaeick Lee(Korea Institute of Science and Technology,) ; Sangwon Cha(Hankuk University of Foreign Studies) pp.110-114 https://doi.org/10.5478/MSL.2018.9.4.110
초록보기
Abstract

Since accumulation of chemicals in deciduous teeth can occur from the second trimester of fetal development to shedding, a deciduous tooth has been considered as an attractive biomatrix for estimating individual chemical exposures recently. Therefore, detection of organic chemicals from teeth has received an increasing attention in exposomics research. Most previous studies on organic chemical analysis of teeth not only focused on a few targeted chemicals but also ignored potential contaminants from an enamel surface or a dental pulp. Recently, our group started developing a multi-class organic analysis method for deciduous teeth and tried to find a proper incubation condition of tooth materials. Our results showed that incubation with methanolic HCl provided the best performance among tested.

Mass Spectrometry Letters