• Title/Summary/Keyword: ECD

Search Result 498, Processing Time 0.041 seconds

Residual Analysis of Insecticides (Lambda-cyhalothrin, Lufenuron, Thiamethoxam and Clothianidin) in Pomegranate Using GC-μECD or HPLC-UVD

  • Hem, Lina;Park, Jong-Hyouk;Shim, Jae-Han
    • Korean Journal of Environmental Agriculture
    • /
    • v.29 no.3
    • /
    • pp.257-265
    • /
    • 2010
  • In this study, the residual levels of four insecticidal compounds (lambda-cyhalothrin, lufenuron, thiamethoxam, and clothianidin) were monitored in the pomegranate, in order to assess the risk to consumers posed by the presence of such residues. The insecticides were applied at the recommended dose rates onto pomegranate trees. The samples were then collected at harvesting time after several treatments (two, three, and four treatments). After sample preparation progressed through the clean-up procedure, lufenuron, thiamethoxam, and clothianidin residues were analyzed via a HPCL-UVD, and the lambda-cyhalothrin residue was analyzed via a GC-${\mu}ECD$. The versatility of this method was evidenced by its excellent linearity (>0.9998 to 1) at broad concentration ranges. The mean recoveries evaluated from the untreated sample spiked with two different fortification levels ranged from 72.45 to 113.90%, and the repeatability (as a relative standard deviation) resulted from triplicate recovery tests was in a range from 0.80 to 11.75%. The residues of all insecticides determined from treated pomegranate samples and their LOD levels (lunfenuron, 0.01; lambda-cyhalothrin, 0.005; thiamethoxam, 0.01; clothianidin, 0.02 mg/kg) were much lower than their MRLs (0.5 mg/kg).

Comparative Study on Initial Symptoms Using Single Photon Emission Computer Tomography in Schizophrenia (뇌 Single Photon Emission Computer Tomography 영상을 이용한 정신분열병 환자의 초기 증상 차이에 대한 연구)

  • Lee, Jin-Gu;Kim, Seong-Min;Seo, Young-Duk;Kim, Ki-Seong;Wang, Seong-Keun;Chee, Ik-Seung;Kim, Jeong-Lan
    • Korean Journal of Biological Psychiatry
    • /
    • v.17 no.3
    • /
    • pp.127-135
    • /
    • 2010
  • Objectives : This study was conducted to compare between hallucination group and delusion group in patient with schizophrenia, using Brain $^{99m}Tc$-ECD PECT. Methods : Among 16 patients with less than 3 schizophrenic episodes, 8 patients whose initial symptom was hallucination were assigned to the hallucination group, and other 8 patients with initial sumptom of delusion were assinged to the hallucination group. All of the patients clinically evaluated using the PANSS and BPRS. Both groups of patients and 8 healthy subjects underwent $^{99m}Tc$-ECD PECT. Results : Score of thinking disturbance subscale of BPRS were significantly lower in the hallucination group than the delusion group. In SPECT analysis, the hallucination group showed significantly increased perfusion in some areas of the right temporal lobe, bilateral limbic lobes and left parietal lobe compared to delusion group. Both group had a reduced rCBF in some areas of the frontal lobe. Conclusion : The hallucniation group, compared with the delusion group, showed significantly increased regional cerebral blood flow in some regions. Therefore, this data suggests that different neural substrates may affect the process of auditory hallucination and delusion.

Energy analysis-based core drilling method for the prediction of rock uniaxial compressive strength

  • Qi, Wang;Shuo, Xu;Ke, Gao Hong;Peng, Zhang;Bei, Jiang;Hong, Liu Bo
    • Geomechanics and Engineering
    • /
    • v.23 no.1
    • /
    • pp.61-69
    • /
    • 2020
  • The uniaxial compressive strength (UCS) of rock is a basic parameter in underground engineering design. The disadvantages of this commonly employed laboratory testing method are untimely testing, difficulty in performing core testing of broken rock mass and long and complicated onsite testing processes. Therefore, the development of a fast and simple in situ rock UCS testing method for field use is urgent. In this study, a multi-function digital rock drilling and testing system and a digital core bit dedicated to the system are independently developed and employed in digital drilling tests on rock specimens with different strengths. The energy analysis is performed during rock cutting to estimate the energy consumed by the drill bit to remove a unit volume of rock. Two quantitative relationship models of energy analysis-based core drilling parameters (ECD) and rock UCS (ECD-UCS models) are established in this manuscript by the methods of regression analysis and support vector machine (SVM). The predictive abilities of the two models are comparatively analysed. The results show that the mean value of relative difference between the predicted rock UCS values and the UCS values measured by the laboratory uniaxial compression test in the prediction set are 3.76 MPa and 4.30 MPa, respectively, and the standard deviations are 2.08 MPa and 4.14 MPa, respectively. The regression analysis-based ECD-UCS model has a more stable predictive ability. The energy analysis-based rock drilling method for the prediction of UCS is proposed. This method realized the quick and convenient in situ test of rock UCS.

Monitoring of Pesticide Residues in Herbal Medicines (유통 한약재의 잔류농약 모니터링)

  • Lee, Sun-Hwa;Kim, Hyeong-Soo;Kim, Yong-Mu;Kim, Woo-Seong;Won, Yeong-Jun;Chae, Gab-Yong;Kim, Ok-Hee;Park, Heung-Jai;Jeong, Seong-Wook
    • Journal of Environmental Science International
    • /
    • v.15 no.8
    • /
    • pp.811-817
    • /
    • 2006
  • We were carried out to monitor pesticide residues in herbal medicine. In Korea Pharmacy, these are no critics for pesticides except 5 kinds of organic chlorines (BHC, DDT, Aldrin, Endrin, Dieldrin) and heavy metals. We analysed 53 kinds of pesticides consisted of 14 kinds of organochlorines, 20 kinds of organophosphoruses, and 19 kinds of pesticides estimated endocrine disruptor on 373 samples consisted with 30kinds of herbal medicine. In this study, Domestic, Chinese and Japanese herbal medicines were tested with GC/ECD, GC/NPD and then confirmed with GC/MSD. Recoveries were 75$\sim$l10% in ECD detector and 76$\sim$97% in NPD detector. Detection limits were 0.004$\sim$0.064ppm in ECD detector and 0.006$\sim$0.094ppm in NPD detector. Organochlorines and others were not detected in samples.