• Journal of Food Hygiene and Safety
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• v.36 no.3
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• pp.228-238
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• 2021

The aim of this research was to develop a rapid and easy multi-residue method for determining dimethipin, omethoate, dimethipin, chlorfenvinphos and azinphos-methyl in agricultural products (hulled rice, potato, soybean, mandarin and green pepper). Samples were prepared using QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) and analyzed using gas chromatography-tandem mass spectrometry (GC-MS/MS). Residual pesticides were extracted with 1% acetic acid in acetonitrile followed by addition of anhydrous magnesium sulfate (MgSO₄) and anhydrous sodium acetate. The extracts were cleaned up using MgSO₄, primary secondary amine (PSA) and octadecyl (C₁₈). The linearity of the calibration curves, which waas excellent by matrix-matched standards, ranged from 0.005 mg/kg to 0.3 mg/kg and yielded the coefficients of determination (R²) ≥ 0.9934 for all analytes. Average recoveries spiked at three levels (0.01, 0.1, 0.5 mg/kg) and were in the range of 74.2-119.3%, while standard deviation values were less than 14.6%, which is below the Codex guideline (CODEX CAC/GL 40).

• Journal of Food Hygiene and Safety
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• v.36 no.3
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• pp.220-227
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• 2021

Fluoroimide is a fungicide and is also used as a pesticide for persimmons and potatoes. The established fluoroimide pesticide analysis method takes a long time to perform and uses benzene, a carcinogen. In addition, a lower limit of quantification is required due to enforcement of the Positive List System. Therefore, this study aimed to improve the analysis method for residual fluoroimide to resolve the problems associated with the current method. The analytical method was improved with reference to the increased stability of fluoroimide under acidic conditions. Fluoroimide was extracted under acidic conditions by hydrogen chloride (4 N) and acetic acid. MgSO₄ and NaCl were used with acetonitrile. C₁₈ (octadecylsilane) 500 mg and graphitized carbon black 40 mg were used in the purification process. The experiment was conducted with agricultural products (hulled rice, potato, soybean, mandarin, green pepper), and liquid chromatograph-tandem mass spectrometry was used for the instrumental analysis. Recovery of fluoroimide was 85.7-106.9% with relative standard deviations (RSDs) of less than 15.6%. This study reports an improved method for the analysis of fluoroimide that might contribute to safety by substituting the use of benzene, a harmful solvent. Furthermore, the use of QuEChERS increased the efficiency of the improved method. Finally, this research confirmed the precise limit of quantification and these results could be used to improve the analysis of other residual pesticides in agricultural products.

• Journal of the Daesoon Academy of Sciences
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• v.44
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• pp.177-212
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• 2023

In this study, discussions of the suppression of cultural diversity in communities was conducted. First, based on the studies conducted so far and recent changes, the oppression that exists between the Chinese government and ethnic minorities was considered. The visible suppression mentioned was the expansion of Han Chinese Mandarin language education, sanctions on minority languages, and the expansion of higher education at the exclusion of minority identities. In terms of 'invisible' oppression, urbanization, urban development with modernization at the forefront, and the use of officials from minority ethnic groups educated by the central government were items that were discussed. Next, the case of Latin America was examined. In particular, attention was paid to the theory of resistance against Europeans and European culture. Based off of the worries and experiences of Latin American intellectuals who have underwent oppression as individuals from culturally diverse backgrounds, a mature theory was formulated that could be used to defend Chinese minorities in the future. There is a specificity to the problem of Chinese minority communities. However, from a large perspective, experience and self-critical exploration in Latin America serve as an opportunity to expand the specificity of Chinese minority communities. Their situation resembles previous situations in Latin America when native cultures were being culturally eroded by Europe. Thus, as Latin American scholars argue, a shift in perception is necessary. In addition to this, in the text, it is likewise necessary to reflect on diversity, freedom, and mutualistic respect. There are proposals advocating for the realization of Heyibutong (和而不同 harmony but not through sameness) based on the situation in China. In the process of this consideration, much thought was given about what the observed communities are like and what a hypothetically desirable community would be like. This extends not only to Chinese minority communities and native residents of Latin America, but also to Asians in the United States and foreigners in Korea. Through this, it is hoped that desirable communities characterized by cultural diversity can be skillfully pursued.