• 제목/요약/키워드: Single residual analytical method

검색결과 11건 처리시간 0.04초

건강기능식품 중 잔류용매 분석법 개발 및 모니터링 (Analytical Method Development and Monitoring of Residual Solvents in Dietary Supplements)

  • 이화미;신지은;장영미;김희연;김미혜
    • 한국식품과학회지
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    • 제42권4호
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    • pp.390-397
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    • 2010
  • Residual solvents in foods are defined as organic volatile chemicals used or produced in manufacturing of extracts or additives, or functional foods. The solvents are not completely eliminated by practical manufacturing techniques and they also may become contaminated by solvents from packing, transportation or storage in warehouses. Because residual solvents have no nutritional value but may be hazardous to human health, there is a need to remove them from the final products or reduce their amounts to below acceptable levels. The purpose of this study was to develop and evaluate an analytical method for the screening of residual solvents in health functional foods. Furthermore, the aim of this study was to constitute a reasonable management system based on the current state of the market and case studies of foreign countries. Eleven volatile solvents such as MeOH, EtOH, trichloroethylene and hexane were separated depending on their column properties, temp. and time using Gas Chromatography (GC). After determining the GC conditions, a sample preparation method using HSS (Head Space Sampling) was developed. From the results, a method for analyzing residual solvents in health functional foods was developed considering matrix effect and interference from the sample obtained from the solution of solvents-free health functional foods spiked with 11 standards solutions. Validation test using the developed GC/HSS/MS (Mass Spectrometry) method was followed by tests for precision, accuracy, recovery, linearity and adequate sensitivity. Finally, examination of 104 samples grouped in suits was performed by the developed HSS/GC/MS for screening the solvents. The 11 solvents were isolated from health functional foods based on vapor pressure difference, and followed by separation within 15 minutes in a single run. The limt of detection (LOD), limit of quantification (LOQ), recovery and coefficient of variation (C.V.) of these compounds determined by the HSS/GC/MS were found to be 0.1 pg/mL, 0.1-125 pg/g, 51.0-104.6%, and less than 15%, respectively. Using the developed HSS/GC/MS method, residual solvent from 16 out of 104 health functional products were detected as a EtOH. This method therefore seems t o be a valuable extension ofanalytical method for the identification of residual solvents in health functional food.

농산물 중 살균제 Isopyrazam의 개별 잔류분석법 확립 (Method Development and Validation for Analysis of Isopyrazam Residues in Agricultural Products)

  • 김지윤;김자영;함헌주;도정아;오재호;이영득;허장현
    • 농약과학회지
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    • 제17권2호
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    • pp.84-93
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    • 2013
  • Isopyrazam은 신규 농약으로 현재 국내에는 공정분석법이 확립되어 있지 않아 농산물 중 잔류농약 분석을 위한 개별 분석법 개발이 필요하다. 본 연구는 현미, 대두, 고추, 감귤, 참외, 오이를 대표 농산물로 선정하여 isopyrazam에 대한 공정 개별 분석법을 확립하고자 수행되었다. Isopyrazam의 syn과 anti 이성질체를 분석하기 위해 여러 가지 추출, 분배 및 정제방법을 비교하면서 최적의 조건을 충족해 가며 분석법을 확립하였다. 대표 농산물 시료 중 함유된 isopyrazam은 acetonitrile로 추출한 후 n-hexane으로 액-액 분배하였으며, florisil을 이용하여 정제한 후 HPLC/UVD로 최종 분석하였다. 시료 중 현미와 대두는 n-hexane/acetonitrile을 이용한 유지제거 과정을 추가하였다. 본 분석법의 isopyrazam에 대한 정량한계는 1.0 ng (S/N > 10)이었고, 분석정량한계는 0.04 mg $kg^{-1}$이었다. 회수율은 isopyrazam syn과 anti-isomer에서 각각 81.0~105.4%, 80.8~105.6%이었으며, 반복 간 분석오차는 10% 미만이었다. 분석성분에 대한 확인을 위하여 LC/MS SIM을 이용하였다. 본 연구에서 확립된 isopyrazam의 분석법은 우수한 정량성 및 재현성, 분석과정의 편의성을 고려할 때 농산물 중 잔류농약에 대한 검사 및 안전성 평가를 위한 공정 분석법으로 활용될 수 있을 것으로 사료된다.

헥사콥터의 구동기 고장 검출 및 분리 방법 (Actuator Fault Detection and Isolation Method for a Hexacopter)

  • 박민기
    • 전기전자학회논문지
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    • 제23권1호
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    • pp.266-272
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    • 2019
  • 멀티콥터는 수직 이착륙 할 수 있다는 장점 때문에 활용이 증가하고 있으며 이러한 멀티콥터의 정상적인 동작을 위해서는 고장 검출과 분리 문제가 매우 중요하다. 본 논문에서는 해석적 방법에 기반하여 헥사콥터 구동기의 고장을 검출하고 분리하는 새로운 방법을 제안한다. 제안한 방법에서는 헥사콥터의 수학적 모델로부터 추정한 구동기의 각속도를 이용하여 잔차를 새롭게 정의하고 생성된 잔차와 문턱값을 비교하여 구동기의 고장을 검출한다. 고장이 검출되면 헥사콥터의 동역학 모델과 생성된 잔차를 결합하여 고장을 분리한다. 제안한 방법은 수학적 모델을 기반으로 하여 간단하면서도 효과적이다. 헥사콥터 구동기의 단일 고장 상황을 가정한 시뮬레이션을 통해 제안한 방법의 유효성을 검증하였다.

Practical formula for determining peak acceleration of footbridge under walking considering human-structure interaction

  • Cao, Liang;Zhou, Hailei;Chen, Y. Frank
    • Structural Engineering and Mechanics
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    • 제83권6호
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    • pp.729-744
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    • 2022
  • In this paper, an analytical formulation is proposed to predict the vertical vibration response due to the pedestrian walking on a footbridge considering the human-structure interaction, where the footbridge and pedestrian are represented by the Euler beam and linear oscillator model, respectively. The derived coupled equation of motion is a nonlinear fourth-order partial differential equation. An uncoupled solution strategy based on the combined weighted residual and perturbation method) is proposed to reduce the tedious computation, which allows the separate integration between the bridge and pedestrian subsystems. The theoretical study demonstrates that the pedestrian subsystem can be treated as a structural system with added mass, damping, and stiffness. The analysis procedure is then applied to a case study under the conditions of single pedestrian and multi pedestrians, and the results are validated and compared numerically. For convenient vibration design of a footbridge, the simplified peak acceleration formula and the idea of decoupling problem are thus proposed.

보의 회전 및 진동제어를 위한 동적 모델 타당성 연구 (A Study on the Valid Dynamic Modeling for the Slewing and Vibration Suppression Control of Beam)

  • 곽문규;남상현
    • 소음진동
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    • 제11권2호
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    • pp.292-300
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    • 2001
  • This research is concerned with the validation of the modeling technique and controller design for slewing beam structures. When cantilever beam rotates about axes perpendicular to the undeformed beam's longitudinal axis, it experiences inertial loading. Hence, the beam vibrates from the initial stage of slewing. In this paper, the analytical model for a single slewing flexible beam with surface bonded piezoelectric sensor and actuator is developed using the Hamilton's principle with discretization by the assumed mode method. Comparisons with the theoretical model are made based upon the frequency responses and time responses. A new factor called the coupling coefficient is introduced to incorporate the discrepancies between the theoretical and experimental results. The slewing is achieved by applying the PID control, which is found to be less sensitive to vibrations. The vibrations are controlled by PPF controller, which is found to be effective in suppressing residual vibrations after slewing. The vibrations occurred during slewing is difficult to control because the piezoceramic actuator is not powerful enough to overcome inertial loadings.

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회전지능보의 능동진동제어 (Active Vibration Control of Slewing Smart Beam)

  • 남상현;곽문규
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2000년도 춘계학술대회논문집
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    • pp.257-262
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    • 2000
  • This research is concerned with the active vibration control of slewing smart structures subjected to rotating disturbance. When cantilever beam rotates about axes perpendicular to the undeformed beam's longitudinal axis, it experiences inertial loading. Hence, the beam vibrates after the slewing ends. In this paper, the analytical model for a single slewing flexible beam with surface bonded piezoelectric sensor and actuator is developed using the Hamilton's principle with discretization by the assumed mode method. The theoretial model is verified by the experimental open loop frequency response data. The controller is designed for residual vibration suppression after slewing. The designed cotroller is a positive position feedback (PPF) controller for controlling the first mode vibration.

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Separation and recovery of semi-volatile substances of Cnidii Rhizoma, Aucklandiae Radix and Amomum Fructus by reduced pressure collections and GC-MS

  • Lee, In-Ho;Byun, Chang Kyu;Eum, Chul Hun;Kim, Taewook;Lee, Sam-Keun
    • 분석과학
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    • 제33권1호
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    • pp.11-22
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    • 2020
  • When extracting semi-volatile components of herbal medicines using hot water vapor, some substances may react with water vapor or oxygen, and some volatile substances may be lost, when using an organic solvent extraction method has the disadvantage that it may contain a non-volatile material and residual organic solvent. In addition, it is inefficient to separate semi-volatile substances from herbal medicines into each single component and conduct biological activity research for each component to determine the effective ingredient, and some components may be lost in the separation process. In this study, semi-volatile substances evaporated under two pressure-reduced conditions in Chinese herbal medicines such as Cnidii Rhizoma, Aucklandiae Radix and Amomum Fructus were separated by cooling with liquid nitrogen. Those were analyzed by gas chromatography-mass spectrometry (GC-MS) to identify the components, and this method may be used to study biological activities at the cellular level. The substances separated under reduced pressure, essential oil obtained by simultaneous distillation extraction (SDE) method and substances by using solid phase micro-extraction (SPME) from Cnidii Rhizoma, Aucklandiae Radix and Amomum Fructus were analyzed by GC-MS. In the case of Cnidii Rhizoma and Aucklandiae Radix, there were some differences among the essential oil components obtained by SDE and those identified by low temperature capture (CT) and SPME method, these were believed to be produced by some volatiles reacting with water or oxygen at the boiling point temperature of water.

An Elastic-Plastic Stress Analysis in Silicon Carbide Fiber Reinforced Magnesium Metal Matrix Composite Beam Having Rectangular Cross Section Under Transverse Loading

  • Okumus, Fuat
    • Journal of Mechanical Science and Technology
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    • 제18권2호
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    • pp.221-229
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    • 2004
  • In this work, an elastic-plastic stress analysis has been conducted for silicon carbide fiber reinforced magnesium metal matrix composite beam. The composite beam has a rectangular cross section. The beam is cantilevered and is loaded by a single force at its free end. In solution, the composite beam is assumed perfectly plastic to simplify the investigation. An analytical solution is presented for the elastic-plastic regions. In order to verify the analytic solution results were compared with the finite element method. An rectangular element with nine nodes has been choosen. Composite plate is meshed into 48 elements and 228 nodes with simply supported and in-plane loading condations. Predictions of the stress distributions of the beam using finite elements were overall in good agreement with analytic values. Stress distributions of the composite beam are calculated with respect to its fiber orientation. Orientation angles of the fiber are chosen as $0^{circ},\;30^{circ},\;45^{circ},\;60^{circ}\;and\;90^{circ}$. The plastic zone expands more at the upper side of the composite beam than at the lower side for $30^{circ},\;45^{circ}\;and\;60^{circ}$ orientation angles. Residual stress components of ${\sigma}_{x}\;and \;{\tau}_{xy}$ are also found in the section of the composite beam.

An investigation of lead absorption in an electric accumulator factory with the use of personal samplers

  • Williams M.K.;King E.;Walford Joan
    • 대한예방의학회:학술대회논문집
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    • 대한예방의학회 1994년도 교수 연수회(환경)
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    • pp.561-575
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    • 1994
  • Williams, M K., King, E., and Walford, Joan (1969). Brit. J. industr. Med., 26, 202-216. An investigation of lead absorption in an electric accumulator factory with the use of personal samplers. Thirty-nine lead workers and controls, in stable conditions of exposure, each wore personal lead-in-air samplers daily for two weeks. During the second week samples for blood lead, urinary lead, urinary coproporphyrin, urinary $\gamma$-aminolevulinic acid (ALA), the punctate basophil count, and haemoglobin were taken daily. Duplicate estimations were made on one day. The lead exposures of men doing almost identical jobs differed by ratios of up to four to one. This could be attributed on y to personal differences in working habits. The correlation coefficients and regression equations of the biochemical tests with lead-in-air and with each other were determined. The mean values and $95\%$ confidence limits of single determinations of some of the biochemical tests corresponding to the two commonly accepted TLVs of lead-in-air (0-20 and 0-15 mg./$m^{3}$) were calculated from the regression equations. For each biochemical test the variation due to analytical error, the variation from day to day within subjects and the residual variation about the regression on lead-in-air were calculated. Previous estimates of the latter are not known. Excessive confidence may be placed in an index of exposure due to its low coefficient of variation within subjects unless the coefficient of variation between subjects about regression is taken into account. The correction for specific gravity of estimations of lead and ALA in spot samples of urine was found to reduce slightly the residual variation between subjects about the regression on lead-in-air and to increase the correlations with lead-in-air and with the other biochemical tests, but these changes were not statistically significant. The modified method used for estimating blood lead and urinary lead is described and validated.

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원유중 미량 설파제 검출방법 비교에 대한 실험적 연구 (An experimental study on the comparison of trace amount of sulfonamides detection method in raw milk.)

  • 황원무;이성모;손봉환;이원창
    • 한국가축위생학회지
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    • 제20권1호
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    • pp.79-93
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    • 1997
  • The sulfonamide is one of potentiative antimicrobial agents which is being used widely in veterinary medicine for control of several animal diseases such as mastitis as well as for promotion of growth. However, the misusages of sulfonamides in food producing animals, especially cattle produce several considerable problems in human health caused from residues of this antibiotic in milk product. To determine the most effective analytical methods for residual sulfonamides in raw milk, this study was performed comparatively using by some applicable screening detecting method such as TTC, Charm II test (sulfonamides), and Lactek tests (sulfamethazine kit). The positive result from screening tests was confirmed by HPLC method. Milk samples (540 raw milks) were collected from dairy farms. Results of this study are summariezed as follorrs ; 1. All samples (540 raw milks) showed negative response from TTC test, however, 18 raw milks of those samples responded positively to Charm II test. 2. By Lactek test, residual sulfamethazine was detected from 4 raw milks. Fifteen raw milks of 18 samples which were classified as positive one by Charm II test, showed positive response 3. Retention time of sulfonamides added at the level of 100ppb into sklm milk was ranged from 1.55 minute to 23.3 minute. Recovery rates of sulfonamides were variable from 6.7% upto 94.2% depended on the types of sulfonamlde. 4. Single type of sulfonamides was detected from 10 raw milk samples, 2 types of sulfonamides from 3 samples and 3 types from 2 raw milks by HPLC. 5. Sulfonamides was detected in this study were 5 types : 11 samples for sulfisomidine, 5 samples for sulfamethazine, 3 samples for sulfadlmethoxine, 2 samples for sulfathiazole and 1 sample for sulfadiazine. 6. The highest levels of residual sulfonamides was 210.3 ppb of sulfamethazine but the lowest concentration of residue was 2.2 ppb of sulfamethazine and sulfisomidine, respectively. Number of samples detected positively in this experiment were belows : above 100 ppb for 1 sample (4.5%) (sulfamethazine), 50~100 ppb for 4 samples (18.1%) (each 2 samples for sulfamethazine and sulfisomidine, respectively), 25~50 ppb for 6 samples (27.1%) (2 sulfisomidine, each 1 sample for sulfadiazine, sulfadimethoxine, sulfamethazine and sulfathiazole, respectively), 10~25ppb for 3 samples (13.7%) (3 sulfisomidine), and below 10ppb for 8 samples (36.4%) (4 sulfisomidine, 2 sulfadimethoxine and each 1 for sulfamethazine and sulfathiazole).

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