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Lee, Gwang Jin,Lee, Jeong Hee,Park, Jeong Hill,Kwon, Sung Won,Lim, Johan,Lee, Sungim,Lee, Jeongmi Elsevier 2018 Analytica chimica acta Vol.1037 No.-
<P><B>Abstract</B></P> <P>An intuitive and practical way to control chemical equivalence of secondary metabolites in herbal materials based on chromatographic fingerprints deserves a thorough discussion, yet it is relatively unexplored. For the first time, we propose a mixture of three similarity indices, the congruence coefficient, the average of the peak area ratios, and the larger value between the maximum peak area ratio and the reciprocal of the minimum peak area ratio, to make up for the weak points of some widely used similarity indices and to evaluate the chemical equivalence of two fingerprints from various perspectives. The three similarity values are fed into a three-dimensional kernel density estimation to determine the quality of herbal materials. This estimation enables precise detection of anomalies in the absence of prior quality determination experience. Forty <I>Atractylodes</I> samples similar in appearance and indiscriminately used for medical purposes were used to demonstrate the effectiveness of the developed approach. After a reference sample was postulated, a quality assessment of the 40 samples was performed using the three similarity values and the estimated kernel density. The samples that were judged by the developed approach to be of good quality were compared with those chosen by the most popular approach using decision criterion of a single similarity index. The benefits of the proposed approach were evident in that the qualified samples had the composition ratio and individual concentrations of multi-components closer to those of the reference in general, and their inter-sample deviation was significantly smaller.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A novel method was developed to assess chemical equivalence of herbal materials. </LI> <LI> A mixture of three similarity indices from chromatographic fingerprints was used. </LI> <LI> Three-dimensional kernel density estimation was applied in herbal fingerprints. </LI> <LI> The new method was successfully applied to quality assessment of 40 real samples. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Lee, Min Sang,Lee, Kyuri,Nam, Min Woo,Jeong, Kyung Min,Lee, Jung Eun,Kim, Nak Won,Yin, Yue,Lim, Su Yeon,Yoo, Da Eun,Lee, Jeongmi,Jeong, Ji Hoon THE KOREAN SOCIETY OF INDUSTRIAL AND ENGINEERING 2018 Journal of Industrial and Engineering Chemistry Vol.65 No.-
<P><B>Abstract</B></P> <P>The inherent vulnerability of protein biologics to high temperature is the origin of their limited use in clinical settings where proper storage and handling systems are not available. Herein, we demonstrate the first application of natural deep eutectic solvents (NADES) as a temperature-stable storage medium for a real therapeutic protein, human interferon-alpha 2 (IFN-α2). A formulation of IFN-α2 based on a NADES composed of choline chloride and fructose at a 1:1 molar ratio (CCl:Fru) had no influence on the activity of IFN-α2. The NADES provided an appropriate environment for effective protection of IFN-α2 from thermal denaturation at mid (37°C) and high (70°C) temperatures during long-term (90 days) and short-term (2h) storage. Protein stability in the presence of CCl:Fru was demonstrated by orthogonal or complementary methods, including in vitro activity assay, circular dichroism spectroscopy and extrinsic fluorescence spectroscopy. In view of their biocompatibility, customizable properties, and the simplicity of synthesis and use, NADESs are suggested as a green and improved short-term and long-term storage medium that could facilitate the development of room-temperature biologics.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Jeongmi Lee,Hireem Kim,Seulgi Kang,Namwook Baik,Inseon Hwang,Doo Soo Chung 대한약학회 2020 Archives of Pharmacal Research Vol.43 No.9
Pharmaceuticals and pesticides are importantanalytes of interest in clinical, environmental, and food analysesfor ensuring public health. Sample pretreatment stepsare often prerequisites for the quantitative analysis of thesecompounds, which are generally present in low concentrationsin samples with complex matrices. In compliancewith the current trend towards green analytical chemistry,the replacement of conventional toxic organic solvents withecofriendly and safe solvents has been pursued in developingsample pretreatment methods. Subsequent to several reportsin 2017, deep eutectic solvents (DESs) have been increasinglyapplied as desirable alternative solvents in numeroustypes of sample pretreatment methods for the analysis ofpharmaceuticals and pesticides. The present review summarizesanalytical methods involving DESs as extractionsolvents and as the reaction media or functional materialsfor preparing adsorbents to quantify pharmaceuticals andpesticides in various matrices.
Lee, Jeongmi,Jung, Dasom,Park, Keunbae Elsevier 2019 Trends in analytical chemistry Vol.118 No.-
<P><B>Abstract</B></P> <P>New-generation solvents termed deep eutectic solvents (DESs) are attracting increasing attention as eco-friendly solvents in analytical chemistry. Recently, a new subclass of DESs called hydrophobic DESs (hDESs) has been reported. hDESs are generally immiscible with water and have high extraction efficiency for nonpolar analytes; thus, they have been suggested as potential extraction media to replace toxic organic solvents or expensive hydrophobic ionic liquids. Since the first introduction of hDESs in 2015, a growing number of studies on the application of hDESs in sample preparation methods have been reported. The present review provides an overview on the preparation and physicochemical properties of hDESs, followed by applications of hDESs in the extraction of organic and inorganic analytes from aqueous environments. In this review, up-to-date studies of conventional (liquid–liquid extraction) and miniaturized (liquid-phase microextraction) scale processes will be discussed with a focus on work up to January 2019.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The first review focused on hydrophobic DESs is presented. </LI> <LI> Synthesis, properties, and applications of hydrophobic DESs are overviewed. </LI> <LI> Hydrophobic DESs are water-immiscible and can replace toxic organic solvents. </LI> <LI> Hydrophobic DESs can serve as efficient extraction medium for LLE and LPME. </LI> </UL> </P>
Lee, Myoung Eun,Ko, Keon-hee,Park, Na-Hyun,Lee, Wonwoong,Yoo, Hye Hyun,Lee, Jeongmi,Choi, Yong Seok,Hong, Jongki Elsevier 2018 Microchemical Journal Vol.143 No.-
<P><B>Abstract</B></P> <P>Analysis of marine biotoxins in high-lipid bivalves has several limitations due to the coexistence of lipid matrices, low biotoxin concentrations, and the different physiochemical properties of the various biotoxins. In this study, a sensitive and reliable method to simultaneously determine six diarrhetic shellfish poisoning (DSP) toxins (five acidic and one neutral biotoxins) in oysters and mussels was developed based on UHPLC-MS/MS-multiple ion reaction monitoring (MRM) using time segment polarity switching. For effective sample pretreatment, three protocols including syringe filtration, Strata™-X solid phase extraction (SPE), and freezing lipid filtration combined with SPE (FLF + SPE) were evaluated, and FLF + SPE method was shown to be the most effective with high lipid removal efficiency. Aging effects of the UHPLC mobile phase on MS detection sensitivity and retention time shift of DSP toxins were carefully examined. The developed method provided good recoveries ranging from 81.0 to 119.6%, showing no significant matrix effect and assay was linear with coefficients of determination above R<SUP>2</SUP> > 0.99 for all analytes. Validation tests using a certified reference material (CRM) and spiking DSP toxins (OA and DTX-1 at 1.07 μg/g, and DTX-2 at 0.86 μg/g) showed this method to be acceptable, with a relative standard deviation of <0.17% and recovery ranging from 87.29 to 109.97%. Finally, the established method was successfully applied to quantify DSP toxins in 40 oyster and mussel samples collected from Korean fishery markets, ensuring sea food safety.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Three extraction protocols were examined for determining lipophilic DSP toxins in high-lipid bivalves </LI> <LI> SPE combined with FLF was shown the best analytical performance in terms of cleanup efficiency, matrix effect, and sensitivity of DSP toxins. </LI> <LI> Simultaneously determined different polarity DSP toxins in a single run using time segment polarity switching mode </LI> <LI> Validated quantification of trace DSP toxins through CRM analysis and spiking experiments </LI> <LI> Successful monitoring the levels of DSP toxins in high-lipid bivalves </LI> </UL> </P>