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Development and Feasibility Evaluation of CsPbBr3 Dosimeter for Brachytherapy (근접방사선치료용 CsPbBr3 선량계 제작 및 적용가능성 평가)

  • Yang, Seung-Woo;Park, Sung-Kwang
    • Journal of the Korean Society of Radiology
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    • v.16 no.4
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    • pp.405-410
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    • 2022
  • In brachytherapy, a radiation source is inserted into the body to kill tumor tissue. Therefore, it is important to accurately measure the location of the source and the dose distribution. In this study, a dosimeter that can be used for brachytherapy was developed using CsPbBr3 which is cheaper than the existing detector materials and has a simpler manufacturing process. The CsPbBr3 dosimeter performance was evaluated by analyzing reproducibility, linearity, and distance dependence in 192Ir source. As a result of reproducibility evaluation, the RSD was 1.36%, which satisfies the standard value of 1.5%. As a result of the linearity evaluation, the R2 value was 0.9993, which satisfies the standard R2 of 0.9990. The distance dependence evaluation showed a signal value that decreased exponentially as the distance increased. The evaluation results show that the CsPbBr3 dosimeter satisfies the evaluation criteria and can be used as a brachytherapy quality assurance dosimeter.

Objective and Relative Sweetness Measurement by Electronic-Tongue (전자혀를 이용한 객관적 상대 단맛 측정)

  • Park, So Yeon;Na, Sun Young;Oh, Chang-Hwan
    • The Journal of the Convergence on Culture Technology
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    • v.8 no.6
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    • pp.921-926
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    • 2022
  • Sugar solutions (5%, 10%, 15% and 20%) were tested by seven sensors of Astree E-Tongue for selecting a sensor for sweetness. NMS sensor was chosen as a sensor for sweetness among two sensors (PKS and NMS sensors selected in first stage) by considering precision, linearity and accuracy. Sugar, fructose, glucose and xylitol (5%, 10% and 15%) were tested by E-tongue. The principal component analysis (PCA) result by E-Tongue with seven sensors at 5% concentration level of four sweetners was not satisfactory (Discrimination index was -0.1). On the other hand, the relative NMS sensor response values were derived as 1.08 (fructose), 0.99 (glucose) and 1.00 (xylitol) comparing to sugar. Only the E-Tongue relative glucose response 0.99 was different from 0.5~0.75 of the relative sweetness range reported as the human sensory test results. Considering the excellent precision (%RSD, 1.53~3.64%) of E-Tongue using NMS single sensor for three types of sweeteners compared to sugar in the concentration range of 5% to 15%, replacing sensory test of sweetened beverages by E-Tongue might be possible for new product development and quality control.

Alcohol content analysis for Takju, a representative traditional liquor in Korea (대한민국 대표 전통주 탁주의 알코올 도수 분석)

  • Oh, Chang-Hwan
    • The Journal of the Convergence on Culture Technology
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    • v.8 no.6
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    • pp.631-636
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    • 2022
  • Alcohol content, which is an important standard for Takju, a traditional multiple parallel fermentation liquor called makgeolli, is a factor that can affect the flavor. For alcohol content analysis, the distillation/hydrometry technique is mainly used. In this study, we analyzed the alcohol content of 14 commercially available Takju by the distillation/hydrometry technique and the improved GC method, respectively, after verifying the reliability of improved GC method. The precision and accuracy of the GC method were satisfactory, and LOQ and LOD were evaluated as 0.5% and 0.1% of ethanol contents, respectively. Among the three Takju exceeding the labelled alcohol content ±1, one Takju was quantitated as alcohol content 9.9% (by GC method) and 10.1% (distillation/hydrometry technique) exceeding labelled 6.0%. It was within the analytical error range of alcohol content for other two Takju, where the alcohol contents were exceeded -1.1%. The average precision (%RSD) of 14 Takju analyzed by the distillation/hydrometry technique (36.2%) and the GC method (12.8%), confirming that the GC method was better than the other. The improved GC method was evaluated to be effective in managing and improving the alcohol content standard of Takju with the wide range of alcohol content.

Method validation of marker compounds from Angelicae Dahuricae Radix as functional food ingredients (건강기능식품 원료로서 구릿대의 지표성분 분석법 검증)

  • Bo-Ram Choi;Dahye Yoon;Hyeon Seon Na;Geum-Soog Kim;Kyung-Sook Han;Sookyeong Lee;Dae Young Lee
    • Journal of Applied Biological Chemistry
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    • v.65 no.4
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    • pp.343-348
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    • 2022
  • This study was performed to establish an analytical method for the standardization of Angelicae Dahuricae Radix as a functional ingredient. We established six compounds including oxypeucedanin hydrate (1), byakangelcol (2), oxypeucedanin (3), imperatorin (4), phellopterin (5) and isoimperatorin (6) as marker compounds of Angelicae Dahuricae Radix. An analytical method using Ultra Performance Liquid Chromatography (UPLC) was established and validated for marker compounds of Angelicae Dahuricae Radix. The specificity was confirmed by the chromatogram from UPLC and the value of coefficient determination was also higher than 0.999, indicating high linearity. The relative standard deviation (RSD) and recovery of marker compounds were less than 5% and in the range of 90- 110%, respectively, which means that this method has high accuracy and precision. Therefore, this analytical method could be used as basic data for the development of functional ingredients for health functional food of Angelicae Dahuricae Radix.

A simple method to determine lycopene in solid supplementary food preparations using saponification and liquid chromatography (비누화 및 액체크로마토그래프를 활용한 고상 건강기능식품 중 라이코펜 분석법 개발)

  • Young Min Kim;Ye Bin Shin;Min Kyeong Kwon;Jin Hwan Kim;Ji Seong Kim;Dong-Kyu Lee;Myung Joo Kang;Yong Seok Choi
    • Analytical Science and Technology
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    • v.36 no.3
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    • pp.105-112
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    • 2023
  • Lycopene, a carotenoid hydrocarbon is known to have effects on reducing cardiovascular risk factors, blood lipids, and blood pressure. Thus, a lot of supplementary foods with lycopene in several dosage forms like soft capsule filled with liquid and hard capsule filled with powder are available in a market. Recently, however, our research group found that the lycopene assay in Supplementary Food Code of South Korea is only valid for oily lycopene preparation. Thus, here, we developed a simple method to determine lycopene in solid preparations for Supplementary Food Code of South Korea using saponification and liquid chromatography with an absorbance detector. The method was validated following Ministry of Food and Drug Safety guidelines. All validation parameters observed in this study were within acceptable criteria of the guidelines (selectivity, linearity of r2 ≥ 0.991, lower limit of quantification of 0.0149 mg/mL, accuracy as recovery (R) between 92.70 and 97.18 %, repeatability as relative standard deviation (RSD) values of R between 0.85 and 1.59 %, and reproducibility as the RSD value of interlaboratory R of 3.70 %). Additionally, the practical sample applicability of the validated method was confirmed by accuracy between 98.81 and 101.59 % observed from its lycopene certified reference material (CRM) analyses. Therefore, the present method could contribute to fortify the supplementary food safety management system in South Korea.

Determination of bromine in 1000 ㎍/g Cl standard solution by ID-ICPMS (동위원소희석 질량분석법에 의한 1000 ㎍/g 염소 표준용액 중 브롬 불순물 분석)

  • Park, Chang Joon;Suh, Jung Kee;Song, Hyun Joo;Lee, Dong Soo
    • Analytical Science and Technology
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    • v.19 no.1
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    • pp.1-8
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    • 2006
  • The isotope dilution method was used for the determination of Br impurity in $1000{\mu}g/g$ Cl standard solution. Since relatively pure KCl salt was used for the preparation of the Cl standard solution, the Br impurity determination suffers from both spectral and non-spectral interferences due to the presence of a large amount of K and Cl matrices. AG2-X8 anion-exchange resin was employed to separate the Br analyte from the matrices, and RF power was raised to 1500 W and nebulizer gas flow rate was lowered to 0.77 L/min to reduce background from the $ArArH^+$ molecular ions. The Br impurity in the $1000{\mu}g/g$ Cl standard solution was determined to be 43.7 ng/g with the standard addition method. The analytical result was in good agreement with 41.2 ng/g (RSD 1.6%) determined by the isotope dilution method to lower uncertainty from poor reproducibility of the anion-exchange process.

Quantification of sulfur from organic and inorganic materials for determination of 35C (35C 측정을 위한 유기물과 무기물에서 황의 정량)

  • Lee, H.N.;Kang, S.H.;Song, B.C.;Sohn, S.C.;Jee, K.Y.
    • Analytical Science and Technology
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    • v.22 no.2
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    • pp.186-190
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    • 2009
  • The oxidation studies of a sulfur to a sulfate ion by various oxyhalide oxidants in organic (thiourea, methionine) and inorganic (sulfate, thiophosphate) compounds were carried out in an acidic solution. The optimized result of the oxidation reaction was obtained when a bromate compound (${BrO_3}^-$) as an oxidant and a 3 M $HNO_3$ solvent were used. The chemical yield for the oxidation of the organic and inorganic sulfur compounds to a sulfate ion was monitored as 80% for thiophosphate, 87% for methionine, and 100% for thiourea and sulfate within 5% RSD. The oxidations of thiourea required at least 1.6 equivalents of the bromate in an acidic solution. In the case of the oxidation of methionine and thiophosphate, the oxidation yields were above 80% if the bromate was used at 20 times higher than that of the substrates. The sulfate ion was quantitatively measured by using a GPC counting of $^{35}S$ followed by precipitates of $BaSO_4$. A quenching correction curve for the $^{35}S$ counting was obtained to use the difference via the precipitate weight result.

Development of Ceramide NP Analysis Method in Cosmetic Formulations Using Liquid Chromatography (액체크로마토그래피를 이용한 화장품 제형 내 세라마이드엔피 분석법 확립)

  • Ye Ji Lee;Young Eun Kim;Jae Yong Seo;Hyun Dae Cho
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.49 no.4
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    • pp.291-298
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    • 2023
  • In this study, a quantitative analysis method was developed using high-performance liquid chromatography (HPLC) to analyze the content of ceramide NP in lotion, cream, and cleanser formulations in cosmetics. The analysis was performed using a C18 column, and the mobile phase was set at a ratio of 70 : 30 for acetonitrile and methanol, the flow rate was set to 0.8 mL/min, and the column temperature was set to 20 ℃. The method was verified by analyzing specificity, linearity, limit of detection, limit of quantitation, accuracy, and precision in accordance with the ICH guidelines. As a result of validating the method, the linearity of the calibration curve was excellent (R2 = 0.99984). The accuracy of the lotion, cream, and cleanser formulations was confirmed with a recovery rate ranging from 95.11% to 100.48%. The precision analysis showed a low relative standard deviation (RSD) of less than 0.26%. The limit of detection was 0.902 ㎍/mL, and the limit of quantitation was 2.733 ㎍/mL. Through this quantitative analysis method of ceramide NP applied in cosmetics, it is expected to assist in the quality control of products by enabling measurement even when it is difficult to separate the main peak due to the influence of interfering substances.

Development of Simultaneous Analysis Method for Dimenhydrinate Containing Complex Pharmaceuticals Using RP-HPLC (고성능 역상 액체 크로마토그래피(RP-HPLC)를 이용한 Dimenhydrinate 함유 복합제제의 동시분석법 개발)

  • Keun-Sik Shin;Jin-Young Park;Jae-Ho Sim
    • The Journal of the Convergence on Culture Technology
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    • v.10 no.5
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    • pp.775-780
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    • 2024
  • In this study, a simultaneous analysis method was developed using reversed-phase high-performance liquid chromatography(RP-HPLC) for the main components of motion sickness medication: Dimenhydrinate, Caffeine, Methyl Paraben, and Propyl Paraben. The analysis was conducted after pretreating the four components, utilizing a C18 column with Acetonitrile and H2O as the mobile phase. UV detection was carried out at a wavelength of 254nm. As a result of the experiment, the values of Resolution(Rs) was well over Rs > 1.5, which indicates that the separation of the four components was efficient. Additionally, the symmetry factor of the components was 0.989, 1.120, 1.256, and 1.280, respectively, showing their symmetrical stability. In the stability assessment, the calibration curves for the four components showed excellent linearity with R2 > 0.9991 to 0.9998. Furthermore, the limit of detection(LOD) ranged between 0.017 to 3.060㎍/ml, while the limit of quantification(LOQ) ranged between 0.050 to 9.180 ㎍/ml. The recovery rates range from 98.28% to 101.71%, and repeatability showed precision within the range of 0.447 to 0.550, and robustness confirmed values with %RSD < 2. The quantitative analysis results of this study demonstrated the effectiveness of a simultaneous analysis method for motion sickness medication components.

Feasibility of monitoring of fluoroquinolones residual through feather analysis in broilers (육계에서 깃털을 이용한 플루오르퀴놀론계 잔류 모니터링 가능성 조사)

  • Kim, Jae-Ho;Kim, Mi-Hee;Ahn, Gil-Ho
    • Korean Journal of Veterinary Service
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    • v.43 no.3
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    • pp.189-196
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    • 2020
  • This study was conducted to analyze feasibility of monitoring of fluoroquinolnes residual through feather analysis in broilers. The calibration curve showed good linearity (r2≥0.99) within the concentration range of 1~100 ㎍/kg. The limit of detection (LOD) and limit of quantification (LOQ) were validated at ≤0.66 and ≤1.99 ㎍/kg in broiler feather, respectively. The recoveries in feather samples ranged from 94.6 to 114.4% (5.1-15.8% RSD) at the 5 to 20 ㎍/kg spiking levels. The proposed new analytical method proved to be suitable and effective for fluoroquinolnes determination. We also monitored fluoroquinolones residue in 36 samples (broiler that were slaughtered in Gyonggi-do) using this method. Among tested feather samples, enrofloxacin and ciprofloxacin were detected in all samples. In muscle samples, enrofloxacin was detected in 20 (55.6%) samples and ciprofloxacin was not detected.