• Research in Plant Disease
• /
• v.26 no.3
• /
• pp.170-178
• /
• 2020

Most strawberry viruses exist relatively low titers in tissues, and strawberry tissues include high levels of contamination by polysaccharides and phenolic compounds. These traits make the efficiency of strawberry diagnosis difficult. In this study, we tested different commercially available kits and reagents to secure optimal RNA extraction methods to determine virus detection from strawberry leaves. Total RNA was isolated from leaves of strawberry mottle virus (SMoV)-infected strawberry cultivar 'Mihong'. The efficiency of total RNA for virus diagnosis was confirmed through SMoV detection by one-step or two-step reverse transcription and polymerase chain reaction (RT-PCR). Among those, the RNeasy plant RNA kit was best to isolate RNA and the isolated RNA was good enough for further applications. To ensure a reliable detection for strawberry viruses, synthetic diagnosis clones for major seven strawberry viruses such as strawberry mild yellow edge virus, SMoV, strawberry latent ring spot virus, strawberry crinkle virus, strawberry pallidosis associated virus, strawberry vein banding virus and strawberry necrotic spot virus have been constructed. Based on the synthetic genes in each clone, primer sets for seven strawberry viruses were designed and tested an RT-PCR condition through a simultaneous application of the same annealing temperature that allowed to achieve an efficient and convenient diagnosis.

• Journal of Soil and Groundwater Environment
• /
• v.12 no.2
• /
• pp.55-64
• /
• 2007

An analytical method using ion-exchange chromatography was developed for simultaneous quantification of low-molecularweight organic acids ($C_1-C_6$ aliphatic carboxylic acids) and inorganic anions, and then applied to the assessment of ground water contaminated by leachates from a municipal solid waste landfill. Peak interferences of halide ions to organic acids were removed by pretreatment of water samples with Ag-containing cartridges. This method allowed accurate detection of low-molecular weight organic acids (i.e., formate, acetate, propionate, pyruvate, succinate, and oxalateas) low as 0.5 mg/L with a linear dynamic range up to 20 mg/L within 11 min run time along with typical inorganic anions. High level of pyruvate and low level of formate and acetate were detected in groundwater and landfill leachates using the analytical method. Pyruvate concentration in groundwater showed a significant correlation with concentrations of $Cl^-$ and $HCO_3^-$, and pyruvate levels decreased along the downgradient from the landfill, indicating the sources of pyruvate are landfill leachate.

• Journal of Korean Ophthalmic Optics Society
• /
• v.9 no.2
• /
• pp.381-389
• /
• 2004

To investigate changes of multi-purpose solutions for soft contact lens(MPS) depending on using period or keeping temperature, we evaluate four brands of MPS. No significant difference was seen in protein deposit removing efficacy after samples had used for 24 weeks and kept at $4^{\circ}C$, $20^{\circ}C$ or $30^{\circ}C$. The pH values of the samples of 4 brands measured weekly over the 24 week testing period. The initial average pH value of samples were 7.0, 7.5, 7.6 or 8.2. One brand of MPS was in the range of the threshold for ocular awareness, which is outside the zone of 6.6 ~ 7.8. During the testing period, the pH value were decreased in using period-dependent manner. At the 24th week, the average pH values of samples turned to 6.6, 7.2, 7.2 or 7.7. However, the difference of keeping temperature was not associated with decreased levels of pH values. After 24 weeks, one of total 36 samples was contaminated by bacteria. Furthermore, the change of components was shown after 24 weeks in the analysis using thin layer chromatography and the analysis of UV absorption pattern. The results of our study provides that the keeping temperature of MPS is not the important factor of changes of MPS, but the using period of MPS can cause contact lens wearers discomfort.

• Journal of Food Hygiene and Safety
• /
• v.23 no.3
• /
• pp.257-263
• /
• 2008

As Standards and Specifications of the Saengsik-classes has been established since 2005 by KFDA. The microbial Standards and Specifications of the Saengsik-classes is as follows; no detection in Escherichia coli, colony forming unit less then 1,000/g in Bacillus cereus, colony forming unit less then 100/g in Clostridium perfringens respectively. Contamination levels of Total aerobic bacteria, Escherichia coli, Bacillus cereus and Clostridium perfringens in Saengsik-classes were monitored. Total aerobic bacteria counts in Saengsik-classes was $1{\times}10^1{\sim}5.3{\times}10^7cfu/g$, for Bacillus cereus $1{\times}10^2{\sim}9{\times}10^2cfu/g$, for Clostridium perfringens $1{\times}10^1cfu/g$. Escherichia coli, was not isolated from all Saengsik-classes. Thess results will provide information for introduction of HACCP system to ensure microbial safety of Saengsik-classes.

• Korean Journal of Food Science and Technology
• /
• v.18 no.6
• /
• pp.458-467
• /
• 1986

This study was conducted to investigate the contamination level of some heavy metals for common restaurant meals in Seoul area and further to estimate the total dietary intake of heavy metals from the meals. The samples included seolong-tang (beef and rice soup) or galbi-tang (beef-rib soup), yeukkye-jang (spicy beef soup), doenjang-chigye-bab (boiled rice with soy paste stew), bibim-bab (boiled rice with assorted mixtures), and bibim-naengmyon (buckwheat vermicelli with assorted mixtures), which were separated into drained residues and fluids and determined for their heavy metal contents by atomic absorption spectrophotometry. The average concentrations of heavy metals in drained residues and fluids of 105 meal samples were 0.034 ppm, 0.017 ppm in Cd, 0.179 ppm, 0.073 ppm in Pb, 0.491 ppm, 0.308 ppm in Cu and 4.624 ppm, 1.403 ppm in Zn, respectively. The total amount of heavy metals per meal was $28\;{\mu}g\;Cd$, $145\;{\mu}g\;Pb$, $416\;{\mu}g\;Cu$ and $3654\;{\mu}g\;Zn$. The total dietary intake per day was estimated to give $84\;{\mu}g\;Cd$, $434\;{\mu}g\;Pb$, $1247\;{\mu}g\;Cu$ and $10960\;{\mu}g\;Zn$. Intake levels of Cd and Pb were higher than the daily intake limit established by FAO/WHO.

• Analytical Science and Technology
• /
• v.14 no.5
• /
• pp.442-450
• /
• 2001

In this study, we collected PM10(particulate matter less than $10{\mu}m$) by using a high volume air sampler from March 2000 to September 2000 to investigate the contamination level and the distribution characteristics of heavy metals in the ambient air in Ulsan area. Samples were pretreated by the microwave extraction methods, and heaby metals (Cr, Cu, Zn, Cd, Ni, As, and Pb) were quantified by using and ICP-MS system. The highest PM10 concentrations in the ambient air were $85.6{\mu}g/m^3$ and the aberage value was $37.1{\mu}g/m^3$. The maximum levels of each heavy metal were as follows: $2.5{\mu}g/m^3$ for Fe(Yeocheon-dong), $0.41{\mu}g/m^3$ for Zn(Nammok-2-dong), $0.061{\mu}g/m^3$ for Cd(Yeocheon-dong), $0.20{\mu}g/m^3$ for Pb(Yeocheon-dong), $0.037{\mu}g/m^3$ for Ni(Yeoncheon-dong), $0.88{\mu}g/m^3$ for Cu(Yaeum-dong), $0.042{\mu}g/m^3$ for Cr(Yaeum-dong), and $0.015{\mu}g/m^3$ for As(Onsan). Among concentration of heavy metals, Ni and Zn compounds were highly correlated with a correlation coefficient of 0.87 at Nammok-2-dong.

• Journal of Bio-Environment Control
• /
• v.17 no.4
• /
• pp.297-305
• /
• 2008

A series of experiments were conducted to suggest efficient in vitro germination conditions to improve germination rate and aseptic seedling production in chicory and garland chrysanthemum. For this purpose, various levels of NaOCl concentration and soaking treatment time combinations were tasted. Fifteen minutes of soaking treatment with 5% NaOCl solution significantly improved germination and seedling formation percentages and prevented contamination in both chicory 'Precole' and 'Chiavari' and garland chrysanthemum 'Okiku 3'. There was no significant difference in germination response between MS and 1/2 MS medium compositions, but germination and seedling formation were delayed as sucrose concentration increased. Although petri-dish among various culture containers gave rise to improved germination responses in chicory 'Precole', there was no significant difference in germination responses among culture container types in chicory 'Chiavari' and garland chrysanthemum 'Okiku 3'. The ultrasonic treatment stimulated germination and seedling formation in both chicory cultivars but there was no effect in garland chrysanthemum 'Okiku 3'. The results suggested 15 minutes with 5% NaOCl for seed sterilization, 1/2 MS medium with no sucrose and petri-dish as proper medium composition and culture container, and 120 minutes with 5% NaOCl solution of ultrasonic treatment as promoting method for in vitro germination in chicory and garland chrysanthemum.

• Journal of Korean Society of Environmental Engineers
• /
• v.28 no.8
• /
• pp.836-842
• /
• 2006

Pine needle samples(1 year, 2 year, 3 year old) were collected in Seoul and Ansung to investigate the deposition characteristics of atmospheric PCBs depending on exposure periods. Total PCBs concentration of pine needle samples in Seoul and Ansung showed 2,429, 1,198 pg/g DW(dry weight), respectively. PCB homologs concentration of pine needle samples decreased with increasing chlorine-substituted compounds. It showed that higher chlorine- substituted compounds in existing particle phase compared to lower chlorine-substituted compounds existing in gaseous phase were difficult to accumulate lipids of the pine needles samples. The results of regression analysis between exposure periods in the atmosphere and concentration of total PCBs measured in pine needles at two sites showed significant levels($R^2>0.94$, p<0.01), which implies that atmospheric PCBs accumulated on pine needles with positive linearity depending on exposure periods in this study. Therefore pine needle samples can be used as passive air sampler(PAS) for monitoring air contamination for a long time in different sites.

• Korean Journal of Soil Science and Fertilizer
• /
• v.29 no.4
• /
• pp.424-431
• /
• 1996

This study was carried out to provide information for establishing counter measures of soil pollution through analysis of Cd. Cu, Pb, and Zn in paddy soils and brown rice. Cadmium, Cu, Pb, and Zn contents in soils were analyzed and distribution maps for these heavy metals were prepared. Heavy metal contents in brown rice were also measured. Average contents of Cd, Cu, Pb, and Zn in surface paddy soils extracted with 0.1 N HCl were 7.4, 35.8, 98.9, and $118.8mg\;kg^{-1}$, respectively. These were 9 times (Cu) to 50 times (Cd) higher than the background level of heavy metals in unpolluted paddy soils in Korea. The contents of Pb and Zn were lower than those measured in 1980, whereas Cd content did not decrease. The levels of heavy metal contamination in paddy soils may not affect growth or yield of rice plant, however, Cd contents indicated a level of serious concern to humans. The average contents of Cd, Cu, Pb, and Zn in brown rice were 0.38, 2.38, 1.31 and $22.31mg\;kg^{-1}$, respectively.

• Food Science and Preservation
• /
• v.22 no.4
• /
• pp.559-566
• /
• 2015

The aim of this study was to develop an analytical method for determination of T-2 toxin and HT-2 toxin level in cereals and to survey their levels using LC-MS/MS. The T-2 and HT-2 toxins were simultaneously analyzed by electrospray ionization with a positive ion mode and multiple reaction monitoring (MRM) after filteration and immuno-affinity column clean-up. A matrix-matched standard calibration used for quantification and recoveries of T-2 and HT-3 toxins were in the range of $100.6{\pm}7.2%$ and $96.8{\pm}9.4%$, respectively. Limits of detection and quantification of T-2 and HT-2 toxins were estimated to be 0.5 and $1.5{\mu}g/kg$, respectively. Each repeatability (RSRr) of T-2 and HT-2 toxins was determined to be 0.9~6.0%, and 4.9~6.1%, respectively. Total 115 samples cereals were collected from 9 types of cereals for analysis. The positive percentages of T-2 and HT-2 toxins obtained from collected samples were found to be 72% and 80%, respectively. The contamination level of T-2 toxin and HT-2 toxin in cereals were $37.1{\mu}g/kg$, and $5.4{\mu}g/kg$, respectively. Therefore, this study suggests that the developed method could be an useful analytical method to determine the T-2 and HT-2 toxin level in cereals and the present data could be used as a reference to estimate the risk assessment.