• Title/Summary/Keyword: Sample preparation method

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Evaluating the Usability of Medical Body Wrap in Whole Body Bone Scan (전신 뼈 검사에서 의료용 신체 고정구의 유용성 평가)

  • Dong-Oh Shim;Woo-Young Jung;Jae-Kwang Ryu;Cheol-Hong Park;Yoon-Jae Kim
    • The Korean Journal of Nuclear Medicine Technology
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    • v.28 no.1
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    • pp.49-56
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    • 2024
  • Purpose: When performing nuclear medicine examinations, body wraps or plastic supports are used to support and immobilize the patient's upper extremities to prevent patient safety accidents. However, the existing plastic supports compromised patient and staff safety, including finger entrapment and falls. Moreover, the body wrap provided by manufacturers compromised image quality such as upper extremities cutoff during whole body bone scan. Therefore, a new design of body wrap was developed to improve the issue, and this study aims to evaluate the usability of this medical body wrap. Materials and Methods: To evaluate the usability of the newly designed medical body wrap, a quality assessment of whole body bone scan images and a user satisfaction survey were conducted. Adult patients (male:female=129:152, age: 60.3±12.4 years, BMI: 24.0±4.2) aged 16 years or older who underwent a whole body bone scan during two periods: June to July 2022 (before improvement, n=139) and June to July 2023 (after improvement, n=142) were randomly selected for image quality evaluation. Five radiotechnologists visually evaluated the posterior view of the whole body bone image, including the left and right elbow (2 points), arm (2 points), whether the hand is extended (2 points), whether the hand is included (2 points), and the number of visible fingers (10 points), with a total of 18 points, which were converted to 100 points and analyzed for difference before and after improvement using an independent sample t-test. The user satisfaction questionnaire was evaluated using a 5-point Likert scale among 16 radiotechnologists from three general hospitals who experienced the new body wrap. Results: The image quality assessment was 82.0±13.8 before the improvement and 89.3±10.1 after the improvement, an average of 7.3 points higher, with a statistically significant difference (t=5.02, p<0.01). The user satisfaction survey showed an overall satisfaction rating of 4.1±0.8 for ease of use, 3.8±0.7 for scan preparation time, 3.9±0.7 for patient safety, 3.8±1.2 for scan accuracy, and 4.2±0.7 for recommendation (87.5% questionnaire response rate). Conclusion: The developed body wrap showed higher image quality and user satisfaction compared to the old method. Considering these results, it is deemed that the new body wrap may be more useful than existing methods.

An Evaluation of Vitek MS System for Rapid Identification of Bacterial Species in Positive Blood Culture (혈액배양 양성검체에서 패혈증 원인균 신속동정을 위한 Vitek MS 시스템의 유용성 평가)

  • Park, Kang-Gyun;Kim, Sang-Ha;Choi, Jong-Tae;Kim, Sunghyun;Kim, Young-Kwon;Yu, Young-Bin
    • Korean Journal of Clinical Laboratory Science
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    • v.49 no.4
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    • pp.407-412
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    • 2017
  • The aim of this study was to shorten the time required for subculture and bacterial identification and obtain a simple and rapid identification method for new test methods for bloodstream infections. The following results were obtained using a mass spectrometer. In Vitek 2, 208 (81.8%) cases were well-identified and 45 isolates were not identified in blood cultures. Among 208 cases, 146 (57.5%) were Gram positive bacteria and 108 (42.5%) were Gram negative bacteria. In total, 233 were identified to the species level and 21 were identified to the genus level. The identification error was found to be Propionibacterium acnes as Clostridium bifermentans. The accuracy of Enterobacteriaceae, glucose non-fermentative bacilli (GNFB), and staphylococci were 81/83 (97.6%), 12/15 (80.0%), and 72/85 (84.7%), respectively. The concordance rate of Vitek 2 and Vitek MS by the direct method was 81.8% and 45 isolates were not identified. Most of the unidentified bacteria were Gram positive bacteria (N=37). The Gram positive bacteria were streptococci (14), coagulase-negative staphylococci (CNS) (11), enterococci (3), Staphylococcus aureus (2), Micrococcus spp. (2), Bacillus spp. (2) and Actinomyces odontolyticus, Finegoldia magna, and Peptostreptococcus spp. The results reporting time was reduced to 24~72 hours compared to the conventional method. The rate of identification of the aerobic and anaerobic cultures was similar, but the use of an anaerobic culture did not require a dissolution process, which could shorten the sample preparation time. These results suggest that the method of direct identification in blood cultures is very useful for the treatment of patients. In further studies, it might be necessary to further improve the method for identifying streptococci and CNS, which were lacking in accuracy in this study.

A Study on the Total Mercury (Hg) Monitoring and Methylmercury (MeHg) Analysis method and Exposure Assessment of Methylmercury (MeHg) in Marine Products (수산물 중 총수은 모니터링 및 메틸수은 분석법 고찰)

  • Kwak, Shin-Hye;Kim, Ki-Cheol;Kim, Kyung-A;Kang, Suk-Ho;Kwon, Hye-Jung;Cho, Yun-Sik;Kang, Kyung-Ja;Lee, Pil-Suk;Cho, Wook-Hyun;Moh, Ara;Park, Yong-Bae;Yoon, Mi-Hye
    • Journal of Food Hygiene and Safety
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    • v.33 no.3
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    • pp.168-175
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    • 2018
  • The use of microwave-assisted extraction and an acid-base clean-up process to determine the amount of methylmercury (MeHg) in marine products was suggested in order to improve the complicated sample preparation process. The optimal conditions for microwave-assisted extraction was developed by using a 10% NaCl solution as an extraction solution, setting the extraction temperature at $50^{\circ}C$, and holding for 15 minutes to extract the MeHg in marine products. A NaOH solution was selected as a clean-up substitute instead of L-cysteine solution. Overall, 670 samples of marine products were analyzed for total mercury (Hg). Detection levels were in the range of $0.0006{\sim}0.3801{\mu}g/kg$. MeHg was analyzed and compared using the current food code and the proposed method for 49 samples which contained above 0.1 mg/kg of Hg. Detection ranges of methylmercury followed by the Korea Food Code and the proposed method were $75.25(ND{\sim}516.93){\mu}g/kg$ and $142.07(100.14{\sim}244.55){\mu}g/kg$, respectively. The total analytical time of proposed method was reduced by more than 25% compared with the current food code method.

Determination of $^{14}C$ in Environmental Samples Using $CO_2$ Absorption Method ($Co_2$ 흡수법에 의한 환경시료중 $^{14}C$ 정량)

  • Lee, Sang-Kuk;Kim, Chang-Kyu;Kim, Cheol-Su;Kim, Yong-Jae;Rho, Byung-Hwan,
    • Journal of Radiation Protection and Research
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    • v.22 no.1
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    • pp.35-46
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    • 1997
  • A simple and precise method of $^{14}C$ was developed to analyze $^{14}C$ in the environment samples using a commercially available $^{14}CO_2$ absorbent and a liquid scintillation counter. An air sampler and a combustion system were developed to collect HTO and $^{14}CO_2$ in the air and the biological samples simultaneously. The collection yield of $^{14}CO_2$ by the air sampler was in the range of 73-89% . The yield of the combustion system was 97%. In preparing samples for counting, the optimum ratio of $CO_2$ absorbent to the scintillator for mixing was 1:1. No variation of the specific activity of $^{14}C$ in the counting sample was observed up to 70 days after preparation of the samples. The detection limit for$^{14}C$ was 0.025 Bq/gC, which is the level applicable to the natural level of $^{14}C$. The analytical result of $^{14}C$ obtained by the present method were within ${\pm}6%$ of the relative error from the one by the benzene synthesis. The specific activity of $^{14}C$ in the air collected at Taejon during the period of October 1996 ranged from 0.26 to 0.27 Bq/gC. The specific activity of $^{14}C$ in the air collected at 1km from the Wolsong nuclear power plant a 679 MWe PHWR, was $0.54{\pm}0.03$ Bq/gC. The ranges of specific activities of $^{14}C$ in the pine needles and the vegetations from the areas around the Wolsong nuclear power plant were 0.56-0.67 Bq/gC and 0.23-1.41 Bq/gC, respectively.

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A Study on Teaching-Learning and Evaluation Methods of Environmental Studies in the Middle School (중학교 "환경" 교과의 교수.학습 및 평가 방법 연구)

  • 남상준
    • Hwankyungkyoyuk
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    • v.7 no.1
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    • pp.1-17
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    • 1994
  • This study was performed to determine appropriate teaching-learning and evaluation methods for Environmental Studies. To promote the relevance of our study to the needs of the schools and concerned educational communities of environmental education, we reviewed related literature, conducted questionnaire surveys, interviewed related teachers and administrator, held meetings with experts, and field-tested our findings. For selecting and developing teaching-learning methods of Environmental Studies, findings of educational research in general are considered. moreover, principles of environmental education, general aim of environmental education, orientations of environmental education, and developmental stages of middle school students in educational psychology were attended. In addition, relevance to the purpose of the Environmental Studies curriculum, appropriateness for value inquiry as well as knowledge inquiry, small group centered class organization, social interaction centered teaching-learning process, regional environmental situation, significance of personal environment, evaluation methods of Environmental Studies, multi- and inter-disciplinary contents of the Environmental Studies textbook, suitability to the evaluation methods of Environmental Studies, and emphasis on the social interaction in teaching-learning process were regarded. It was learned the Environmental Studies can be taught most effectively in via of holding discussion sessions, conducting actual investigation, doing experiment-practice, doing games and plate, role-playing and carrying out simulation activities, and doing inquiry. These teaching-learning methods were field-tested and proved appropriate methods for the subject. For selecting and developing evaluation method of Environmental Studies, such principles and characteristics of Environmental Studies as objective domains stated in the Environmental Studies curriculum, diversity of teaching-learning organization, were appreciated. We categorized nine evaluation methods: the teacher may conduct questionnaire surveys, testings, interviews, non-participatory observations; they may evaluate student's experiment-practice performances, reports preparation ability, ability to establish a research project, the teacher may ask the students to conduct a self-evaluation, or reciprocal evaluation. To maximize the effect of these methods, we further developed an application system. It considered three variables, that is, evaluates, evaluation objectives domains, and evaluation agent, and showed how to choose the most appropriate methods and, when necessary, how to combine uses of different methods depending on these variables. A sample evaluation instrument made on the basis of this application system was developed and tested in the classes. The system proved effective. Pilot applications of the teaching-learning methods and evaluation method were made simultaneously; and the results and their implications are as follows. Discussion program was applied in a lesson dealing with the problems of waste disposal, in which students showed active participation and creative thinking. The evaluation method used in this lesson was a multiple-choice written test for knowledge and skills. It was shown that this evaluation method and device are effective in helping students' revision of the lesson and in stimulating their creative interpretations and responces. Pupils showed great interests in the actual investigation program, and this programme was proved to be effective in enhancing students' participation. However, it was also turned out that there must be pre-arranged plans for the objects, contents and procedures of survey if this program is to effective. In this lesson, non-participatory observation methods were used with a focus on the attitudes of students. A scaled reported in general description rather than in grade. Experiment-practice programme was adopted in a lesson for purifying contaminated water and in this lesson, instruction objectives were properly established, the teaching-learning process was clearly specified and students were highly motivated. On the other hand, however, it was difficult to control the class when some groups of students require more times to complete their experiment, and sometimes different results. As regards to evaluation, performance observation test were used for assessing skills and attitudes. If teachers use well-prepared Likert scale, evaluation of all groups within a reasonablely short period of time will be possible. The most effective and successful programme in therms of students' participation and enjoyment, was the 'ah-nah-bah-dah-market' program, which is kind of game of the flea market. For better organized program of this kind, however, are essential, In this program, students appraise their own attitudes and behavior by responding to a written questionnaire. In addition, students were asked to record any anecdotes relating to self-appraisal of changes on one's own attitudes and behaviours. Even after the lesson, students keep recording those changes on letters to herself. Role-playing and simulation game programme was applied to a case of 'NIMBY', in which students should decide where to located a refuse dumping ground. For this kind of programme to e successful, concepts and words used in the script should be appropriate for students' intellectual levels, and students should by adequately introduced into the objective and the procedures of the lessons. Written questionnaire was used to assess individual students' attitudes after the lesson, but in order to acquire information on the changes of students' attitudes and skills, pre-test may have to be made. Doing inquiry programme, in which advantages in which students actually investigated the environmental influence of the areas where school os located, had advantages in developing students' ability to study the environmental problems and to present the results of their studies. For this programme to be more efficient, areas of investigation should be clearly divided and alloted to each group so that repetition or overlap in areas of study and presentation be avoided, and complementary wok between groups bee enhanced. In this programme, teacher assessed students' knowledge and attitudes on the basis of reports prepared by each group. However, there were found some difficults in assessing students' attitudes and behaviours solely on the grounds of written report. Perhaps, using a scaled checklist assessing students' attitudes while their presentation could help to relieve the difficulties.

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Development and Validation of an Analytical Method for Fenpropimorph in Agricultural Products Using QuEChERS and LC-MS/MS (QuEChERS법과 LC-MS/MS를 이용한 농산물 중 Fenpropimorph 시험법 개발 및 검증)

  • Lee, Han Sol;Do, Jung-Ah;Park, Ji-Su;Cho, Sung Min;Shin, Hye-Sun;Jang, Dong Eun;Choi, Young-Nae;Jung, Yong-hyun;Lee, Kangbong
    • Journal of Food Hygiene and Safety
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    • v.34 no.2
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    • pp.115-123
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    • 2019
  • An analytical method was developed for the determination of fenpropimorph, a morpholine fungicide, in hulled rice, potato, soybean, mandarin and green pepper using QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) sample preparation and LC-MS/MS (liquid chromatography-tandem mass spectrometry). The QuEChERS extraction was performed with acetonitrile followed by addition of anhydrous magnesium sulfate and sodium chloride. After centrifugation, d-SPE (dispersive solid phase extraction) cleanup was conducted using anhydrous magnesium sulfate, primary secondary amine sorbents and graphitized carbon black. The matrix-matched calibration curves were constructed using seven concentration levels, from 0.0025 to 0.25 mg/kg, and their correlation coefficient ($R^2$) of five agricultural products were higher than 0.9899. The limits of detection (LOD) and quantification (LOQ) were 0.001 and 0.0025 mg/kg, respectively, and the limits of quantification for the analytical method were 0.01 mg/kg. Average recoveries spiked at three levels (LOQ, $LOQ{\times}10$, $LOQ{\times}50$, n=5) and were in the range of 90.9~110.5% with associated relative standard deviation values less than 5.7%. As a result of the inter-laboratory validation, the average recoveries between the two laboratories were 88.6~101.4% and the coefficient of variation was also below 15%. All optimized results were satisfied the criteria ranges requested in the Codex guidelines and Food Safety Evaluation Department guidelines. This study could serve as a reference for safety management relative to fenpropimorph residues in imported and domestic agricultural products.

Determination of Petroleum Aromatic Hydrocarbons in Seawater Using Headspace Solid-Phase Microextraction Coupled to Gas Chromatography/Mass Spectrometry (HS-SPME-GC/MS를 이용한 해수 내 유류계 방향족탄화수소 분석법)

  • An, Joon Geon;Shim, Won Joon;Ha, Sung Yong;Yim, Un Hyuk
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.17 no.1
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    • pp.27-35
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    • 2014
  • The headspace solid-phase microextraction (HS-SPME) followed by gas chromatography/mass spectrometry procedure has been developed for the simultaneous determination of petroleum aromatic hydrocarbons such as benzene, toluene, ethylbenzene and xylene isomers (BTEX) and polycyclic aromatic hydrocarbons (PAHs) in seawater. The advantages of SPME compared to traditional methods of sample preparation are ease of operation, reuse of fiber, portable system, minimal contamination and loss of the sample during transport and storage. SPME fiber, extraction time, temperature, stirring speed, and GC desorption time were key extraction parameters considered in this study. Among three kinds of SPME fibers, i.e., PDMS ($100{\mu}m$), CAR/PDMS ($75{\mu}m$), and PDMS/DVB ($65{\mu}m$), a $65{\mu}m$ PDMS/DVB fiber showed the most optimal extraction efficiencies covering molecular weight ranging from 78 to 202. Other extraction parameters were set up using $65{\mu}m$ PDMS/DVB. The final optimized extraction conditions were extraction time (60 min), extraction temperature (50), stirring speed (750 rpm) and GC desorption time (3 min). When applied to artificially contaminated seawater like water accommodated fraction, our optimized HS-SPME-GC/MS showed comparable performances with other conventional method. The proposed protocol can be an attractive alternative to analysis of BTEX and PAHs in seawater.

Growth of Fe3O4 Particles and Their Magnetic Properties (Fe3O4 분말제조와 자기적 특성)

  • Kwon, Woo-Hyun;Lee, Seung-Wha;Chae, Kwang-Pyo;Lee, Jae-Gwang;Sur, Jung-Chul
    • Journal of the Korean Magnetics Society
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    • v.19 no.5
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    • pp.180-185
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    • 2009
  • Fe$_3$O$_4$ particles, prepared by a sol-gel method, were examined for their structural characteristic, particle shapes and sizes, and their magnetic properties. Two different chemical compositions (using a mol rate Fe$^{2+}$/Fe$^{3+}$ = 1/2 and only Fe$^{2+}$) and 2-methoxyethanol were used for making proper solutions. And the solutions were refluxed and dry in a dry oven and the samples were fired at 200$\sim$600$^{\circ}C$ in the N$_2$ atmosphere. The formation of single-phased spinel ferrite powders was identified with the X-ray diffraction measurement as they were fired at above 250$^{\circ}C$. The result of scanning electron microscopy measurement showed the increase of annealing temperature yielded the particle size increased. The magnetic transition was observed using the Mossbaur spectroscopy measurement. As the ferrite, prepared with the chemical composition (Fe$^{2+}$/Fe$^{3+}$ = 1/2), was fired at 250$^{\circ}C$, 78% of the ferrite had a ferrimagnetic property and 22% of the ferrite was non-magnetic. In case of preparing the sample with only Fe$^{2+}$ and annealed at 200$^{\circ}C$, it had a single phased spinel structure but its particle size was too small to be ferrimagnetic. The annealing temperature above 250$^{\circ}C$ made powders a spinel structure regardless of the preparation method. They had a typical soft magnetic property and their saturation magnetization and coercivity became larger as the annealing temperature increased.

Anti-inflammatory and Whitening Effects of Protaetia brevitarsis Seulensis Extracts by Oriental Conversion Methods (포제방법에 따른 흰점박이꽃무지(Protaetia brevitarsis Seulensis) 추출물의 항염 및 미백활성에 관한 연구)

  • Sung, Gyeong Ah;Kim, Mi Hye;Park, Soo Nam
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.42 no.4
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    • pp.421-432
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    • 2016
  • In order to find new functional materials for the cosmetics application, we investigated anti-inflammatory and whitening effects of the Protaetia brevitarsis seulensis (P. brevitarsis) extracts, which were prepared by the various oriental conversion methods, as follows; fresh, roasted one time, roasted two times, roasted three times, and steamed. 2,2-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities of the various solvent extracts (80% ethanol, 50% ethanol, ethyl acetate, hexane) of P. brevitarsis extracts were 85.5, 22.4, 37.0 and 19.4% respectively. The 80% ethanol extract with the highest antioxidant activity was used for all experiments. In case of antioxidant activity test of the extracts, all the extracts showed the activities in concentration dependent manner regardless of the sample preparation methods. Superoxide dismutase-like (SOD-like) activities of the extracts roasted three times and steamed were 62.9 and 55.9%, respectively in $500{\mu}g/mL$. Effects of extracts on the inflammation of RAW 264.7 cell induced by lipopolysaccharide (LPS) showed decreasing tendency of $NO{\cdot}$ and prostaglandin $E_2$ ($PGE_2$) production; PBS fresh (38.0%), PBS roasted one time (41.0%), PBS roasted two times (69.8%), PBS roasted three times (70.1%), PBS steamed (78.5%). Intracellular tyrosinase and melanin biosynthesis inhibitory activities of the extracts were decreased in a concentration dependent manner. However, the fresh P. brevitarsis extracts without the oriental conversion method showed 90.7% decrease compared to the control group treated with ${\alpha}$-MSH alone at $500{\mu}g/mL$. Taken together, these results suggest the oriental conversion method can be applied in development of cosmetic materials in order to improve anti-inflammatory and whitening effects of the cosmetics products.

Method Development for Determination of Chlorogenic Acid and Arbutin Contents in Fruits by UHPLC-MS/MS (UHPLC-MS/MS를 이용한 과일류 중 클로로젠산 및 알부틴 동시분석법 개발)

  • Choi, Young-Ju;Jeon, Jong-Sup;Kim, Woon-Ho;Jung, You-Jung;Ryu, Ji-Eun;Choi, Jong-Chul;Chae, Kyung-Suk;Lee, Jin-Hee;Do, Young-Sook;Park, Young-Bae;Yoon, Mi-Hye
    • Journal of Food Hygiene and Safety
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    • v.34 no.5
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    • pp.413-420
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    • 2019
  • In this study, a sample preparation method and a simultaneous determination method by ultra-high performance liquid chromatography coupled with tandem mass spectrometry for 9 isomers of chlorogenic acid and arbutin in fruits were developed. The samples were extracted using 90% methanol (pH 3.0), with the solutions being shaken and then sonicated for 10 min each. After centrifugation at 4,000 rpm for 10 min, the extraction was concentrated under a vacuum at $40^{\circ}C$ using a vacuum evaporator. The residue was dissolved in 5 mL of 5% methanol and filtered through a $0.45{\mu}m$ membrane before UHPLC-MS/MS analysis. The separations were performed on a C18 column with gradient elution of water (containing 0.1% formic acid) and methanol (containing 0.1% formic acid). The specificity, linearity, limit of detection, limit of quantification, accuracy, and precision of the proposed methods were also evaluated.