• Title/Summary/Keyword: Sample preparation method

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Determination of Corticosteroids in Moisturizers by LC-MS/MS

  • Park, Sumin;Choi, Gye Young;Lee, Seon-Ah;Kim, Hyun Jeong;Yum, Hye Yung;Paeng, Ki-Jung
    • Mass Spectrometry Letters
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    • v.7 no.1
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    • pp.26-29
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    • 2016
  • Simultaneous determination of three corticosteroids (clobetasol propionate, betamethasone dipropionate, fluticasone propionate) in moisturizers was performed by using liquid chromatography (LC) coupled with tandem mass spectrometry (MS/MS). Sample preparation was conducted by the liquid-liquid extraction (LLE). Moisturizers include emulsifying agent and it forms micelles. In order to improve the extraction efficiency of corticosteroids trapped in micelle, newly developed-optimized extraction conditions which can remove the matrix effect from moisturizers was applied with various pH conditions in LLE extraction stage of sample preparation. Thus, the addition of 10 μL of 1 M HCl into moisturizers sample before extraction could improve the extraction efficiency. For the quantitative analysis, SRM table that contained specific transition of all of target corticosteroids was created. The developed method was validated for linearity, accuracy, precision, limit of detection (LOD), limit of quantization (LOQ) and recovery. Over the 0.99 r2 value was obtained in calibration standard range. Effective accuracy and precision were also obtained. LODs were below 31 ng/mL and LOQs were estimated below 94 ng/mL for all corticosteroids tested.

A Study on the Effects of Processing Method on the Quality of Soybean Da-sik (콩가루 제조방법과 당의 종류와 양이 콩다식의 품질에 미치는 영향)

  • 정순애;조신호;이효지
    • Korean journal of food and cookery science
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    • v.13 no.3
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    • pp.356-363
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    • 1997
  • Soybean Da-sik was prepared with various soybean powder processing methods (roasting, steaming, and steaming followed by roasting) and sugar types (honey, oligo-sugar), and their sensory and physical characteristics were evaluated to determine the optimum preparation method. The results were as follows: 1. For Sample 1 (roasting soybeans for 30 min at 150$^{\circ}C$ and grinding), the best appearance of Da-sik was obtained when the content of honey was adjusted to 35 g, and the color with 30 g of oligo-sugar by sensory evaluation. The optimum texture was obtained with 40 g of honey, and the optimum chewiness with 30 g of honey Overall, the optimum quality was obtained with 35 g of honey, and oligo-sugar seemed to have less influence on the quality. In case of Sample 2 (four rounds of steaming and drying for 35 min), 40 g of oligo-sugar was found to exhibit the best quality, and honey was less effective. For Sample 3 (three rounds of drying followed by 15 min roasting at 150$^{\circ}C$), the best appearance and color were obtained with 35 g and 40 g of honey, respectively. The texture was most favorable with 40 g of honey, while the chewiness was best with 30 g of honey, suggesting 35 g of honey was the optimum level for Sample 3 soybean powder than oligo-sugar. 2. The springiness, gumminess, hardness and chewiness measured by a texture analyser were highest with Sample 1 containing 30 g of honey, and the cohesiveness with 40 g of honey. 3. For color, the best brightness and yellowness were obtained with Sample 1 with 30 g of honey. The redness was highest with Sample 3 with 40 g of honey. Overall, the desirable recipe for soybean Da-sik was 35 g of honey for Sample 1 and Sample 3, and 40 g of oligo-sugar for Sample 2.

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The Relationship between Professional Nursing Values and Career Preparation Behaviors of Nursing Students (간호학생의 간호전문직관과 진로준비행동 간의 관계)

  • Ko, Young-Ji;Kim, In-Kyung
    • The Journal of Korean Academic Society of Nursing Education
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    • v.17 no.1
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    • pp.62-71
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    • 2011
  • Purpose: The purpose of this study was to examine the relationship between professional nursing values and career preparation behaviors in senior nursing students. Method: The sample consisted of 199 nursing students before getting jobs who attended a nursing vocational college in Daegu and a nursing department of a university in J city of Chungcheongbuk-do. The data were collected from the first of May to the first of June in 2010. Results: The mean score was 106.76 for professional nursing values. The highest reported score of the nursing professional values domains was professionalism of nursing and was followed by nursing practical role and professional self-concept. The mean score was 42.66 for career preparation behavior. There was alow correlation between professional nursing values and career preparation behaviors. Conclusion: This finding suggests nursing students have differences from career preparation behaviors according to viewpoints about nursing as a professional job. Therefore, it is necessary to develop new curriculum and reinforce existing education for developing of professional nursing values. Moreover, nursing education institutes should set up educational objectives related to their general characteristics for improving career preparation behavior.

Index Properties and Undrained Shear Strength of the Pusan Clays by Fall Cone Test (부산점토의 Fall Cone Test에 의한 지수 및 강도특성)

  • ;;Pham Huy Giao
    • Proceedings of the Korean Geotechical Society Conference
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    • 2000.11a
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    • pp.391-398
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    • 2000
  • The index properties of cohesive soils play an important role to examine entire tendency of soil properties. Especially, the Atterberg limits have a good correlation with compression and shear strength of cohesive soils. However, these values strongly depend on their testing methods. In this study, for Pusan clays the Atterberg limits were peformed under different conditions; for example, four kinds of specimen preparation, two kinds of testing equipment, and four kinds of estimating method. And a laboratory vane test was peformed to compare the undrained shear strength with that of the fall cone test. As experimental results, the value of liquid limit performed for oven-dried sample, followed in ASTM D4318, underestimated by about 10% compared to those of another three methods, irrespective to the used equipments. But the value of plastic limit was not influenced by sample preparation methods and equipments. The liquid limits by one-point methods(Leroueil et al., 1996; Nagaraj et al., 1981) were agreed well with those of different methods. Finally, the undrained shear strength by laboratory vane test was relatively larger than that of fall cone test, and the relationship between both showed a bad trend.

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Influence of Sample Preparation on Thermogravimetric Analysis of Poly(Ethylene-co-Vinyl Acetate)

  • Lee, Sang-jin;Choi, Sung-Seen
    • Elastomers and Composites
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    • v.51 no.3
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    • pp.206-211
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    • 2016
  • Experimental error sources for thermogravimetric analysis (TGA) of poly(ethylene-co-vinyl acetate) (EVA) were investigated and sample preparation method to reduce the experimental error was suggested. Maximum dissociation temperatures of EVA for the first and second dissociation reactions ($T_{m1}$ and $T_{m2}$, respectively) were measured. By decreasing the weight of raw EVA, the $T_{m1}$ increased but the the $T_{m2}$ decreased. When weight of the raw EVA was over 10 mg, the TGA curve showed abnormal behaviors. The abnormal TG behaviors were explained by gathering and instantaneous evaporation of acetic acid formed by deacetylation of the VA unit. When TGA analysis of EVA was performed using untreated (raw) EVA, the experimental errors were about 1%. In order to eliminate the abnormal TG behaviors and to reduce the experimental errors, EVA film made by solvent casting was used. For the treated EVA (EVA film), the abnormal TG behaviors did not appear, the $T_{m1}$ decreased by about $2^{\circ}C$ but the $T_{m2}$ increased by about $6^{\circ}C$, and the experimental errors were reduced by 0.5%.

Alternative Sample Preparation Method for Large-Area Cross-Section View Observation of Lithium Ion Battery

  • Kim, Ji-Young;Jeong, Young Woo;Cho, Hye Young;Chang, Hye Jung
    • Applied Microscopy
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    • v.47 no.2
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    • pp.77-83
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    • 2017
  • Drastic development of ubiquitous devices requires more advanced batteries with high specific capacitance and high rate capability. Large-area microstructure characterization across the stacks of cathode, electrolyte and anode might reveal the origin of the instability or degradation of batteries upon cycling charge. In this study, sample preparation methods to observe the cross-section view of the electrodes for battery in SEM and several imaging tips are reviewed. For an accurate evaluation of the microstructure, ion milling which flats the surface uniformly is recommended. Pros and cons of cross-section polishing (CP) with Ar ion and focused ion beam (FIB) with Ga ion were compared. Additionally, a modified but new cross-section milling technique utilizing precision ion polishing system (PIPS) which can be an alternative method of CP is developed. This simple approach will make the researchers have more chances to prepare decent large-area cross-section electrode for batteries.

The Study on Preparation Parameters of $TiO_2$Catalyst for Photodecomposition of Ethanol as a VOC (VOC물질중 에탄올 광분해반응을 위한 $TiO_2$촉매의 제초변수 고찰)

  • 이병용;김성욱;정석진
    • Journal of Korean Society for Atmospheric Environment
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    • v.17 no.4
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    • pp.363-370
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    • 2001
  • In this study, TiO$_2$, the popular photocatalyst, was used to decompose ethanol. TiO$_2$was prepared by the sol -gel method and coated on pyrex stick. A 15W, UV-A lamp was used as the UV light source and il gas chromatography (HP 5890) was used to confirm the concentrations of ethanol, $CO_2$and the intermediates. Variation of preparation parameters and calcination temperature for TiO$_2$photocatalysts in the sol -gel method caused changes of ethanol decomposition activity. The best ethanol photodecomposition activity was obtained on the sample when prepared with 0.14 mol of HCI, a mol of ethanol and 1.3 mol of TTIP ware mixed in sol-gel process and calcinated at 50$0^{\circ}C$ for 3 hours. Acetaldehyde was detected as an intermediate and decomposed to carbon dioxide and water at the end of the reaction.

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A Study on the Photosensitivity of Poly(vinyl cinnamoyl acetate) Developable in Aqueous Base (수계현상성 Poly(vinyl cinnamoyl acetate)의 감광특성에 관한 연구)

  • 신동률
    • Journal of the Korean Graphic Arts Communication Society
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    • v.12 no.1
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    • pp.1.2-15
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    • 1994
  • This is the study which appear the relation between the situation of Anchor point and the qualities of lithographic prints using the uncoated paper. Anchor point were measured by microscopic photography and Kubelka-munk`s method. The situation of Anchor point increased with print density and print though, but it decreased with evenness and rub off. In case of commercial uncoated paper, the situation of Anchor point was optimized when it was 25~35% apporoximately. In preparation of samples for microscopic photography, the samples were used by the resin testing methods. This method used that the resin fixes the printed papers of sample very hard, in preparation of samples for microscopica potography a good result could be gained by this method.

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Methods for the Extraction of DNA from Water Samples for Polymerase Chain Reaction

  • Jung, Jae-Sung;Lee, Young-Jong
    • Journal of Microbiology
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    • v.35 no.4
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    • pp.354-359
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    • 1997
  • Methods for the extraction of DNA from water sample were approximated. Four different procedures of DNA extraction were carried out with pellets obtained from centrifugation of 4 liter water samples. The recovery efficiency and purity of DNA extracted by each method from different sources were compared. DNA yield varied with extraction methods, Method I, which involves enzymatic and freeze-thaw lysis steps and phenol and phenol-chloroform purification of extracted nucleic acid, showed a significantly higher yield and purity than the other methods. The use of glass beads in the DNA extraction methods improved the purity of DNA suitable for PCR. Bovine serum albumin in the PCR reaction mixture was useful in reducing inhibitory effects of contaminants. The efficiency of an extraction method was determined by the detection of the aer of Aeromonas hydrophila with PCR. The lower limit of detection of A. hydrophila from seeded tap water was 2 CFU/ml in PCR when method I was used for DNA preparation.

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Development of Modified Product Consistency Test

  • Park, Kwansik;Jiawei Sheng;Maeng, Sung-Jun;Song, Myung-Jae
    • Proceedings of the Korean Nuclear Society Conference
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    • 1998.05b
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    • pp.391-396
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    • 1998
  • Modified product Consistency Test (M-PCT) has been developed as an alternative to other existing methods in determining the leachability of glass. M-PCT, the leaching method, is a hybrid of MCC-l and PCT, but can provide quicker sample preparation. Larger diameter glass sample (1.0-2.0 mm) than in the PCT method can be used so that the glass beads are more easily produced and cleaned. From the M-PCT, the total mass loss (ML) of glass, the normalized elemental release rate (NLi), pH value of leachate have been obtained. For some selected glasses in which leaching rates have been known, their chemical durablility have been tested using the M-PCT method. The results are compared to the literature data for the glasses. It is found that M-PCT method is reasonable and suitable in determining the leachability of Low and Intermediate level Radioactive Waste glass form, such as the pH, elemental loss and total mass loss.

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