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  • P-ISSN2233-4203
  • E-ISSN2093-8950
Search Word: high performance liquid chromatography, Search Result: 9
초록보기
Abstract

An advanced and reliable high performance liquid chromatography (HPLC)/ultraviolet detector (UV)/ion-trap timeof-flight (IT-TOF) mass spectrometry was developed for the simultaneous quantification of 19 marker compounds in Bangpoong-tong-sung-san (BPTS), a traditional oriental prescription. Various parameters affecting HPLC separation and IT-TOFdetection were investigated, and optimized conditions were identified. The separation was achieved on a Capcell PAK C18 column(1.5 mm × 250 mm, 5 μm particle size) using a gradient elution of acetonitrile and water containing 0.1% formic acid at aflow rate of 0.1 mL/min. The column temperature was maintained at 40oC and the injection volume was 2 μL. IT-TOF systemwas equipped with an electrospray ion source (ESI) operating in positive or negative ion mode. The optimized electrospray ionizationparameters were as follows: ion spray voltage, +4.5 kV (positive ion mode), or -3.5 kV (negative ion mode); drying gas(N2), 1.5 L/min; heat block temperature, 200oC. Automatic MSn (n = 1~3) analyses were carried out to obtain structural informationof analytes. Elemental compositions and their mass errors were calculated based on their accurate masses obtained from aformula predictor software. The marker compounds in BPTS were identified by comparisons between MSn spectra from standardsand those from extracts. Moreover, the libraries of MS2 and MS3 spectra and accurate masses of parent and fragment ionsfor marker compounds were constructed. The developed method was successfully applied to the BPTS extracts and identified 17out of 19 marker compounds in the BPTS extracts.

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Young-Hee Lim(LG Chem) ; Deok-Hie Park(LG Chem) ; Yeu Young Youn(LG Chem) ; Kyung Hoon Kim(LG Chem) ; Hye-Sung Cho(LG Chem) 2011, Vol.2, No.1, pp.16-19 https://doi.org/10.5478/MSL.2011.2.1.016
초록보기
Abstract

Oxidation products of ceftiofur were formed in hydrogen peroxide solution. The structures of the ceftiofur oxidationproducts were characterized by high-performance liquid chromatography/electrospray ionization/tandem mass spectrometry(HPLC/ESI/MS/MS). The products were identified as compounds oxidized at the sulfur of a cephem ring. For further analysis,an experiment was performed using O18-labeled hydrogen peroxide. Results of the density-functional calculations for six possibleoxidation products were in good agreement with the experimental results.

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Yeoun Hur(International Scientific Standards Co. Ltd.) ; Sookil Tae(International Scientific Standards Co. Ltd.) ; Yun-Joo Koh(The Korea Institute for children's Social Development and Rudolph Child Research Center) ; Sung-Hyun Hong(Institute for EONE Laboratories) ; Young Ho Yoon(Institute for EONE Laboratories) ; Haejong Jang(International Scientific Standards Co. Ltd.) ; Sooji Kim(International Scientific Standards Co. Ltd.) ; Kyeong Ho Kim(Kangwon National University) ; Seung Woo Kang(International Scientific Standards Co. Ltd.) ; Youngshin Lee(International Scientific Standards Co. Ltd.) ; Sang Beom Han(Chung-Ang University) 2014, Vol.5, No.2, pp.42-48 https://doi.org/10.5478/MSL.2014.5.2.42
초록보기
Abstract

A specific and sensitive liquid chromatography-electrospray ionization tandem mass spectrometry method (LC-ESIMS/MS) was developed and validated for the simultaneous quantification of porphyrins (coproporphyrin, pentacarboxylporphyrin,hexacarboxylporphyrin, heptacarboxylporphyrin, and uroporphyrin) in human plasma and urine. Acidified plasma samplesand urine samples were prepared by using liquid-liquid extraction using ethyl acetate and protein precipitation with acetonitrile,respectively. The separation was achieved onto a Synergi Fusion RP column (150 mm × 2.0 mm, 4 μm) with a gradient elutionof mobile phase A (0.1% formic acid in 2 mmol/L ammonium acetate, v/v) and mobile phase B (20% methanol in acetonitrile, v/v) at a flow rate of 450 μL/min. Porphyrins and the internal standard (IS), coproporphyrin I-15N4, were detected by a tandemmass spectrometer equipped with an electrospray ion source operating in positive ion mode. Multiple reaction monitoring(MRM) transitions of the protonated precursor ions and the related product ions were optimized to increase selectivity and sensitivity. The proposed method was validated by assessing selectivity, linearity, limit of quantification (LOQ), precision, accuracy,recovery, and stability. The calibration curves were obtained in the range of 0.1-100 nmol/L and the LOQs were estimated as0.1 nmol/L for all porphyrins. Results obtained from the validation study of porphyrins showed good accuracy, precision, recovery,and stability. Finally, the proposed method was successfully applied to clinical studies on the autism spectrum disorder(ASD) diagnosis of 203 Korean children.

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Jukka Pellinen(University of Helsinki) ; Riikka-Juulia Lepistö(University of Helsinki) ; Santeri Savolainen(University of Helsinki) 2018, Vol.9, No.3, pp.77-80 https://doi.org/10.5478/MSL.2018.9.3.77
초록보기
Abstract

The focus of this paper is to present techniques to overcome certain difficulties in quantitative analysis with a time- of-flight mass spectrometer (TOF-MS). The method is based on conventional solid-phase extraction, followed by reversed- phase ultra high performance liquid chromatography of the extract, and mass spectrometric analysis. The target compounds included atenolol, atrazine, caffeine, carbamazepine, diclofenac, estrone, ibuprofen, naproxen, simazine, sucralose, sulfamethox- azole, and triclosan. The matrix effects caused by high concentrations of organic compounds in wastewater are especially signif- icant in electrospray ionization mass spectroscopy. Internal-standard calibration with isotopically labeled standards corrects the results for many matrix effects, but some peculiarities were observed. The problems encountered in quantitation of carbamaze- pine and triclosan, due to nonlinear calibration were solved by changing the internal standard and using a narrower mass win- dow. With simazine, the use of a quadratic calibration curve was the best solution.

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Yongseok Kim(Korea Institute of Science and Technology, Yonsei University) ; Dawon Jeong(Korea Institute of Science and Technology) ; Hophil Min(Korea Institute of Science and Technology) ; Changmin Sung(Korea Institute of Science and Technology) ; Ju-hyung Park(Korea Institute of Science and Technology) ; Junghyun Son(Korea Institute of Science and Technology) ; Kang Mi Lee(Korea Institute of Science and Technology) ; Ho Jun Kim(Korea Institute of Science and Technology) ; Jaeick Lee(Korea Institute of Science and Technology) ; Oh-Seung Kwon(Korea Institute of Science and Technology) ; Ki Hun Kim(Korea Institute of Science and Technology) 2017, Vol.8, No.2, pp.39-43 https://doi.org/10.5478/MSL.2017.8.2.39
초록보기
Abstract

Meldonium is a drug for treating ischemia by expanding the arteries but it can also enhance the performance of sports players. The World Anti-Doping Agency (WADA) has included it in the list of prohibited substances since 2016. Meldonium is one of the challenging substances for anti-doping testing because it is difficult to recover by general liquid-liquid or solid phase extraction due to its permanent charge and high polarity. Therefore, high-performance liquid chromatography (HPLC) is currently used by injecting a diluted urine sample (known as the “dilute-and-shoot” strategy). There is no loss of target compounds in the extraction/cleanup procedure but its high matrix effect could interfere in their separation or detection from the endogenous urinary compounds. We report a single method using high-resolution mass spectrometry that can be used for both screening and confirmation, which follows the “dilute-and-shoot” strategy. In this method, the endogenous compounds’ interfering peaks in the mass spectrum are separated at a high resolution of FWHM 140,000, and the results are suitable for substance detection following the WADA guidelines. The interferences in the obtained mass spectrum of the urine matrix are identified as acetylcholine, lysine, and glutamine by further analysis and database searching. Validation of the method is performed in routine anti-doping testing, and the limit of detection is 50 ng/mL. This method uses simple sample preparation and a general reverse phase HPLC column, and it can be easily applied to other substances.

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Justin Tze-Yang NG(Nanyang Technological University) ; Piliang HAO(Nanyang Technological University) ; Siu Kwan Sze(Nanyang Technological University) 2014, Vol.5, No.4, pp.95-103 https://doi.org/10.5478/MSL.2014.5.4.95
초록보기
Abstract

Characterization and studies of proteome are challenging because biological samples are complex, with a wide dynamic range of abundance. At present the proteins are identified by digestion into peptides, with subsequent identification of the peptides by mass spectrometry (MS). MS is a powerful technique for the purpose, but it cannot identify every peptide in such complex mixtures simultaneously. For accurate analysis and quantification it is important to separate the peptides first by chromatographyinto fractions of a size that MS can handle. With these less complex fractions, the probability is increased of identifying peptides of low abundance that would otherwise experience ion suppression effects due to the presence of peptides of high abundance. Enrichment for peptides with certain post-translational modifications helps to increase their detection rates as well. Electrostatic repulsion-hydrophilic interaction chromatography (ERLIC) is a mixed-mode chromatographic technique which combines the use of electrostatic repulsion and hydrophilic interaction. This review provides an overview of ERLIC and its variousproteomics applications. ERLIC has been demonstrated to have good orthogonality to reverse phase liquid chromatography (RPLC), making it useful as a first dimension in multidimensional liquid chromatography (MDLC) and fractionation of digestsin general. Peptides elute in order of their isoelectric points and polarity. ERLIC has also been successfully utilized for the enrichment for phosphopeptides and glycopeptides, facilitating their identification. In addition, it is promising for the study ofpeptide deamidation. ERLIC performs comparably well or better than established methods for these various applications, and serves as a viable and efficient workflow alternative.

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Si Hyun Kim(Korea Institute of Science and Technology) ; Nu Ri Lim(Korea Institute of Science and Technology) ; Hophil Min(Korea Institute of Science and Technology) ; Changmin Sung(Korea Institute of Science and Technology) ; Han Bin Oh(Sogang University) ; Ki Hun Kim(Korea Institute of Science and Technology) 2020, Vol.11, No.4, pp.118-124 https://doi.org/10.5478/MSL.2020.11.4.118
초록보기
Abstract

An analytical method was developed for hypoxia-inducible factor (HIF) stabilizers based on QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) sample preparation and liquid chromatography–high resolution mass spectrometry analysis. HIF stabilizers potentially enhance the performance of athletes, and hence, they have been prohibited. However, the analysis of urinary HIF stabilizers is not easy owing to their unique structure and characteristics. Hence, we developed the QuEChERS preparation technique for a complementary method and optimized the pH, volume of extraction solvent, and number of extractions. We found that double extraction with 1% of formic acid in acetonitrile provided the highest recovery of HIF stabilizers. Moreover, the composi-tion of the mobile phase was also optimized for better separation of molidustat and IOX4. The developed method was validated in terms of its precision, detection limit, matrix effect, and recovery for ISO accreditation. To the best of our knowledge, this is the first demonstration of the application of the QuEChERS method, which is suitable as a complementary analytical method, in antidoping.

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Aboli Girme(Department of Pharmacology, Pravara Institute of Medical Sciences) ; Ganesh Saste(Pharmanza Herbal Pvt. Ltd.) ; Ashish Chinchansure(Division of Organic Chemistry, CSIR-National Chemical Laboratory) ; Swati Joshi(Division of Organic Chemistry, CSIR-National Chemical Laboratory) ; Rahul Kunkulol(Department of Pharmacology, Pravara Institute of Medical Sciences) ; Lal Hingorani(Pharmanza Herbal Pvt. Ltd.) ; Bhushan Patwardhan(Savitribai Phule Pune University) 2020, Vol.11, No.4, pp.82-89 https://doi.org/10.5478/MSL.2020.11.4.82
초록보기
Abstract

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 MS 1 and MS 2 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 (r 2 ≥ 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.

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Woonyon Kwon(Supreme Prosecutors’ Office) ; SungIll Suh(Supreme Prosecutors’ Office) ; Moon Kyo In(Supreme Prosecutors’ Office) ; Jin Young Kim(Supreme Prosecutors’ Office) 2014, Vol.5, No.4, pp.104-109 https://doi.org/10.5478/MSL.2014.5.4.104
초록보기
Abstract

Nonmedical use of prescription stimulants such as methylphenidate (MPH) and amphetamine (AP) by normal persons has been increased to improve cognitive functions. Due to high potential for their abuse, reliable analytical methods were required to detect these prescription stimulants in biological samples. A direct injection liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was developed and implemented for simultaneous determination of MPH, AP and their metabolites ritalinic acid (RA) and 4-hydroxyamphetamine (HAP) in human urine. Urine sample was centrifuged and the upper layer (100 μL) was mixed with 800 μL of distilled water and 100 μL of internal standards (0.2 μg/mL in methanol). The mixture was then directly injected into the LC-MS/MS system. The mobile phase was composed of 0.2% formic acid in distilled water (A) and acetonitrile (B). Chromatographic separation was performed by using a Capcell Pak MG-II C18 (150 mm × 2.0 mm i.d., 5 μm, Shiseido) column and all analytes were eluted within 5 min. Linear least-squares regression with a 1/x weighting factor was used to generate a calibration curve and the assay was linear from 20 to 1500 ng/mL (HAP), 40-3000 ng/mL (AP and RA) and 2-150 ng/mL (MPH). The intra- and inter-day precisions were within 16.4%. The intra- and inter-day accuracies ranged from -15.6% to 10.8%. The limits of detection for all the analytes were less than 4.7 ng/mL. The suitability of the method was examined by analyzing urine samples from drug abusers.

Mass Spectrometry Letters