• Korean Journal of Environmental Agriculture
• /
• v.40 no.4
• /
• pp.335-344
• /
• 2021

BACKGROUND: Cyantraniliprole is a systemic diamide insecticide that has been used to control lepidopteran pests in agriculture. Cyantraniliprole has become an issue due to its potentiality of unexpectable contamination in rotational crop cultivation. Thus, studies on the evaluation of cyantraniliprole translocated from soil into rotational crops are required. METHODS AND RESULTS: Cyantraniliprole was treated at a yearly maximum application level onto bare soil under greenhouse conditions in two geographically different regions. Lettuce was transplanted and spinach and radish were sown onto the soil 30 and 60 days-plant back intervals (PBIs) after cyantraniliprole treatment. The QuEChERS method was modified and coupled with LC/MS/MS analysis to determine the residues of cyantraniliprole in soil and plant samples. The methods for sample preparation and instrumental conditions were validated to meet the criteria of Codex guidelines and were successful to determine cyantraniliprole quantitatively and qualitatively in the samples. Cyantraniliprole residues in lettuce samples were 0.01 mg/kg for PBI 60 and 0.02 mg/kg for PBI 30, respectively. The residues in spinach samples were 0.01 mg/kg for PBI 60 and 0.01~0.02 mg/kg for PBI 30, respectively. Less than limit of the quantitation (LOQ) level (0.01 mg/kg) of cyantraniliprole was observed in radish samples. The residues in the plant samples were found as the levels less than maximum residue limit (MRL) for leafy and root vegetables. CONCLUSION(S): This study suggests PBI 30~60 days for rotational cultivation of lettuce, spinach and radish in greenhouse soil treated with cyantraniliprole at a yearly maximum application level.

• Korean Journal of Environmental Biology
• /
• v.37 no.4
• /
• pp.592-599
• /
• 2019

Ostrea denselamellosa and Eriocheir japonica samples were collected from the Seomjin River in 2019 as part of the "Research of Host-Associated Bacteria" research program. Almost 200 bacterial strains were isolated from the O. denselamellosa and E. japonica samples and subsequently identified by 16S rRNA gene sequencing. Among the bacterial isolates, ten strains possessed greater than 98.7% sequence similarity with published bacterial species that had not previously been recorded in Korea. These species were phylogenetically diverse, belonging to three phyla, four classes, seven orders, and eight genera. At the genus and class level, the previously unrecorded species belonged to Pseudoalteromonas, Aliivibrio, Rheinheimera, Leucothrix, and Shewanella of the class Gamma-proteobacteria, Olleya of the class Flavobacteriia, Algoriphagus of the class Cytophagia, and Lactococcus of the class Bacilli. The previously unrecorded species were further characterized by examining their Gram staining, colony and cell morphology, biochemical properties, and phylogenetic positions.

• Journal of Species Research
• /
• v.11 no.3
• /
• pp.143-154
• /
• 2022

To obtain unrecorded bacterial species in Korea, various marine samples were collected from Jeollanam-do Province, Korea in 2021. After plating the samples on marine agar and marine R2A agar, and incubating aerobically and anaerobically, approximately 1200 bacterial strains were isolated and identified using 16S rRNA gene sequences. A total of 30 strains showed ≥98.7% 16S rRNA gene sequence similarity with validly published bacterial species but not reported in Korea, indicating that they are unrecorded bacterial species in Korea. The unrecorded bacterial strains belonged to 4 phyla, 7 classes, 13 orders, 19 families, and 22 genera, which were assigned to Azospirllium, Loktanella, and Pseudovibrio of the class Alphaproteobacteria; Grimontia, Halomonas, Marinobacter, Microbulbifer, Photobacterium, Pseudoalteromonas, Pseudidiomarina, Ferrimonas, Shewanella, Simiduia, Thalassotalea, and Vibrio of the class Gammaproteobacteria; Priestia and Enterococcus of the class Bacilli; Persicobacter of the class Cytophagia; Aureivirga of the class Flavobacteriia; Propionigenium and Psychrilyobacter of the class Fusobacteriia; and Tepidibacter of the class Clostridia. The details of the unreported species including Gram reaction, colony and cell morphology, biochemical characteristics, and phylogenetic position are also provided in the description of the strains.

• Journal of Applied Biological Chemistry
• /
• v.59 no.1
• /
• pp.83-90
• /
• 2016

The aim of the present study was to evaluate the degree of metal contamination of the Turag River water and its suitability for irrigation. Twenty water samples were analyzed for physicochemical parameters and metals viz., calcium, magnesium, potassium (K), sodium, copper (Cu), zinc (Zn), iron (Fe), manganese (Mn), lead (Pb), cadmium (Cd), chromium (Cr), and nickel (Ni). All water samples were slightly alkaline to alkaline. Regarding electrical conductivity (EC), all samples were suitable for crop in soils with moderate permeability and leaching. Water samples were medium salinity and low alkalinity hazard classes. In terms of total dissolved solids (TDS), all samples were classified as freshwater. As per sodium adsorption ratio (SAR) and soluble sodium percentage (SSP), all samples were classified as excellent. No residual sodium carbonate (RSC) was detected in any of the samples, indicating suitability for irrigation; and all samples were considered very hard. Cr and Mn contents in all samples were above FAO guideline values and, therefore, these metals were considered toxic. Zn, Cu, Pb, Cd, and Ni concentrations were below acceptable limit for irrigation and do not pose a threat to soil environment. Significant relationships were found between EC and TDS, SAR and SSP, SAR and RSC, and SSP and RSC. The combinations of ions such as K-Zn, K-Fe, K-Cu, K-Mn, K-Pb, Zn-Fe, Zn-Cu, Zn-Mn, Fe-Mn, Cu-Mn, Cu-Pb and Mn-Pb exhibited significant correlation. This study revealed that Turag River water samples are contaminated with Cr and Mn. This fact should not be ignored because water contamination by metals may pose a threat to human health through food chain.

• Toxicological Research
• /
• v.17
• /
• pp.319-321
• /
• 2001

Taihu Lake is a major water source for part of Yangtze Delta, which is one of the most urbanized and economically prosperous areas in China. In last couple of decades, some parts of the lake were highly polluted due to eutrophication. This study analyzed dioxin-like potential and mutagenic potential in surface water samples from Taihu Lake. The samples were prepared by XAD-2 resin procedure. A batch of biological assays, including dioxin-like potential microassay with the rat hepatocyte cell line H411E, and Ames test was employed in the research. Results showed that jour water samples have high content of dioxin-like biological potential, the highest activity TEQ to 2,3,7,8-TCDD was 48 pg/ι in sample 1. The mutagenic effect with reading-frame shifting mechanism was confirmed in 3 of 4 samples. The effective sewage treatment facilities and reliable monitoring surveillance system are urgently needed for this area.

• Environmental Analysis Health and Toxicology
• /
• v.19 no.1
• /
• pp.1-24
• /
• 2004

Since dioxins became a serious concern in Korea, a significant number of investigations have been conducted to address diverse issues related to dioxins. However, the results have not been organized for ready access and use. The principal purposes of the work were to ⅰ) provide an archive of dioxin researches in Korea and ⅱ) give an overview of dioxin contamination. The focus of this work was placed on the contamination levels and characteristics concerning the waste incinerators emissions, environmental media, and biological samples(fishes/shellfishes, foods, and human body). Principal component analysis was conducted to identify common and/or unique features and the important variables associated with the congener patterns. From a comprehensive search of academic journals, research and monitoring project reports, dissertations, and periodicals of other forms, a total of 115 counts were found that met the purposes of this study. The contamination levels of various samples were summarized and compared to those reported in foreign literatures. The congener patterns varied largely with environmental media and distinguished particularly by OCDD, 1,2,3,4,6,7,8-HpCDF, and OCDF for the samples within the same media. The proximity to emission sources differentiated the congener patterns in air and soil samples by the fraction of OCDD.

• Animal cells and systems
• /
• v.16 no.6
• /
• pp.488-497
• /
• 2012

A DNA barcode based on 648 bp of cytochrome c oxidase I (COI) gene aims to build species-specific libraries for animal groups. However, it is hard to recover full-length (648 bp) barcode gene from environmental fecal samples due to DNA degradation. In this study, we designed a new primer set (K_Bird), which amplifies a 226 bp fragment targeted an inner position of full-length COI barcode based on 102 species of Korean birds to improve amplification success, and we attempted to identify bird species from 39 avian fecal samples collected during 4 months from Jinan, South Korea. Simultaneously, we conducted a dietary analysis using a universal DNA mini-barcode (Uni_Minibar) from same fecal samples. In silico analysis on newly designed mini-barcode represented that genetic distances were 0.5% in species and 9.1% in genera. Intraspecific variations of 149 species out of 174 species (86%) between Korea and North America were within the threshold (5.3% threshold in this study). From environmental fecal samples collected in Jinan, we identified seven avian species, which have high similarity (99-100%) with registered COI sequences in GenBank. Eight kinds of prey species, such as moth, spider, fly, and dragonfly, were identified in dietary analysis. We suppose that our strategy applying mini-barcode for environmental fecal samples, might be a useful and convenient tool for species identification and dietary analysis for birds.

• Applied Biological Chemistry
• /
• v.22 no.3
• /
• pp.142-144
• /
• 1979

To investigate the potability of water from rural area of Kyung-Gi-Do, the bacteriological examination of water samples from Yong-In Gun and Hwa-Sung Gun were carried out. The results obtained can be summarized as follows: 1. The total viable cell count showed great difference between the samples; 3 samples included less than $1{\times}10^2$ per ml and 6 samples more than $1{\times}10^4$ per ml. The maximum count arrived at $1{\times}10^5$ per ml. 2. The existence of faecal Streptococcus was confirmed in the samples of 4 areas. 3. For the potability, only one sample was remarked as positive and all the others were judged as negative or suspect.

• Journal of Industrial and Engineering Chemistry
• /
• v.67
• /
• pp.461-468
• /
• 2018

A highly sensitive, selective and rapid method for the determination of lead based on the reaction of lead (II) with 5-(4'-chlorophenylazo)-6-hydroxypyrimidine-2,4-dione (CPAHPD) and the solid phase extraction of the Pb(II)-CPAHPD complex with Amberlite XAD-2000 was developed, in the presence of pH 5.6 buffer solution and Triton X-114 medium. CPAHPD reacts with lead to form a violet complex with a molar ratio of 2:1 (CPAHPD to lead). This complex was enriched by the solid phase extraction with Amberlite XAD-2000. An enrichment factor of 500 was obtained by elution of the complex from the resin with a minimal amount of isopentyl alcohol(0.2 mL). In isopentyl alcohol medium,the molar absorptivity of the complex is $1.13{\times}10^6L\;mol^{-1}cm^{-1}$ at 647 nm. Beer's law is obeyed in the range of $5.0-160ng\;mL^{-1}$ in the measured solution. The relative standard deviation for 10 replicate samples of $50ng\;mL^{-1}$ level is 1.26%. The detection and quantification limits reaches 1.5 and $4.7ng\;mL^{-1}$ in the original samples. The presented procedure was successfully applied for determination of lead content in real samples such as vegetables, waters, biological and soil samples with satisfactory results.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.23 no.4
• /
• pp.333-340
• /
• 2013

Objectives: This study was designed to establish an accurate analytical method for asbestos in a biological sample for determining occupational asbestos-related diseases and relief of the health effects of environmental asbestos. Methods: Biological samples were obtained from lungs of rats following intratracheal instillation of asbestos(Chrysotile, anthophyllite) and were prepared according to digestion method(Wet digestion, high temperature ashing, low temperature ashing). The samples were then analyzed for asbestos fibers using a transmission electron microscope equipped with an energy dispersive X-ray spectrometer. Results: Low temperature plasma ashing removed more of the organic components and reduced fiber loss compared to the wet digestion method, making specimens so prepared more suitable for transmission electron microsocpy. Conclusions: The low temperature ashing technique is the most accurate method for analyzing asbestos in biological samples.