• Journal of Food Hygiene and Safety
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• v.26 no.3
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• pp.203-208
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• 2011

This study was to evaluate the efficacy of sanitizer concentrations and treatment time against two major toad-borne pathogenic microorganisms such as Escherichia coli and Staphylococcus aureus on a stainless steel surface. As a result, stainless steel, treated with 100 ppm of chlorine showed reduction of E. coli(1.56, 1.49, 1.95 log cfu/25 $cm^2$) and S. aureus(0.49, 0.88, 1.27 log cfu/25 $cm^2$) after 0, 5 and 10 min, but none was not detected in treatment with 200 ppm. The population of E. coli(0.73, 0.90, 1.55 log cfu/25 $cm^2$) and S. aureus(0.37, 1.00, 1.45 log cfu/25 $cm^2$) reduced in 35.5% ethanol treated group, but none was not detected in treatment with 70%. The population was reduced E coli(0.28, 0.64, 1.07 cfu/25 $cm^2$) and S. aureus(0.53, 0.87, 0.99 log cfu/25 $cm^2$) by treatment with 45.5 ppm of hydrogen peroxide, but none was not detected in treatment with 91 ppm. Quarternary ammonium compound with 100 ppm was reduced E. coli(0.82, 1.62, 1.71 log cfu/25 $cm^2$) and S. aureus(0.46, 0.93, 1.38 log cfu/25 $cm^2$), but none was not detected in treatment with 200 ppm. Predictive models of sterilization for all 4 disinfectants were suitable to use with $r^2$ value of higher than 0.94. These models may be of use to food services and manufacture of safe products by controlling E. coli and S. aureus without the need for further detection of the organisms.

• Journal of Food Hygiene and Safety
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• v.29 no.3
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• pp.234-240
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• 2014

Fluxapyroxad is classified as carboxamide fungicide that inhibits succinate dehydrogenase in complex II of mitochondrial respiratory chain, which results in inhibition of mycelial growth within the fungus target species. This study was carried out to assure the safety of fluxapyroxad residues in agricultural products by developing an official analytical method. A new, reliable analytical method was developed and validated using High Performance liquid Chromatograph-UV/visible detector (HPLC-UVD) for the determination of fluxapyroxad residues. The fluxapyroxad residues in samples were extracted with acetonitrile, partitioned with dichloromethane, and then purified with silica solid phase extraction (SPE) cartridge. Correlation coefficient($R^2$) of fluxapyroxad standard solution was 0.9999. The method was validated using apple, pear, peanut, pepper, hulled rice, potato, and soybean spiked with fluxapyroxad at 0.05 and 0.5 mg/kg. Average recoveries were 80.6~114.0% with relative standard deviation less than 10%, and limit of detection (LOD) and limit of quantification (LOQ) were 0.01 and 0.05 mg/kg, respectively. All validation parameters were followed with Codex guideline (CAC/GL 40). LC-MS (Liquid Chromatograph-Mass Spectrometer) was also applied to confirm the analytical method. Base on these results, this method was found to be appropriate fluxapyroxad residue determination and can be used as the official method of analysis.

• Journal of Food Hygiene and Safety
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• v.28 no.3
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• pp.279-285
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• 2013

To establish sample preparation method for detection of food-borne pathogens from lettuce, perilla leaves, cucumber, pepper, and cherry tomato, the influences of diluent composition, processing time, and proportion of diluent to sample were examined. Each produce was inoculated with 6.0 log $CFU/cm^2$ of Escherichia coli O157:H7, Salmonella Typhimurium, Listeria monocytogenes, Staphylococcus aureus, and Bacillus cereus. Each produce was treated with 0.1% peptone water, and D/E neutralizing broth. Processing time of produce was 30, 60, 90, and 120s, and the proportion of diluent to sample was 2 : 1, 4 : 1, 9 : 1, and 19 : 1. The number of bacteria after treatment of D/E neutralizing broth was higher than that of 0.1% peptone water (P<0.05). In cherry tomato, the population of S. typhimurium recovered from treated with D/E broth was higher than that recovered from treated with 0.1% peptone water by 1.05 log $CFU/cm^2$ (P<0.05). No difference in numbers of pathogens was observed in processing time. Optimum proportion of diluent to perilla leaf, iceberg lettuce, cucumber, green pepper, and tomato was 9 : 1, 4 : 1, 2 : 1, 2 : 1, and 2 : 1, respectively. These data suggest that D/E neutralizing broth should be recommend as diluent, and the diluent volume applied to produce should be determined in proportion to produce surface area per weight (g).

• Journal of Food Hygiene and Safety
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• v.31 no.5
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• pp.327-334
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• 2016

This study was conducted to establish the standard method for the contents of biotin in milk formulas. To optimize the method, we compared several conditions for liquid extraction, purification and instrumental measurement using spiked samples and certified reference material (NIST SRM 1849a) as test materials. LC-MS/MS method for biotin was established using $C_{18}$ column and binary gradient 0.1% formic acid/acetonitrile, 0.1% formic acid/water mobile phase is applied for biotin. Product-ion traces at m/z 245.1 ${\rightarrow}$ 227.1, 166.1 are used for quantitative analysis of biotin. The linearity was over $R^2=0.999$ in range of $5{\sim}60{\mu}g/L$. For purification, chloroform was used as a solvent for eliminating lipids in milk formula. The linearity was over 0.999 in range of 5~60 ng/mL. The detection limit and quantification limit were 0.10, 0.31 ng/mL. The accuracy and precision of LC-MS/MS method using CRM were 103%, 2.5% respectively. Optimized methods were applied in sample analysis to verify the reliability. All the tested milk formulas were acceptable contents of biotin compared with component specification and standards for nutrition labeling. The standard operating procedures were prepared for biotin to provide experimental information and to strengthen the management of nutrient in milk formula.

• Journal of Food Hygiene and Safety
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• v.35 no.3
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• pp.225-233
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• 2020

By the standards and specifications for hygiene products, three test methods for formaldehyde are specified for each item type of hygiene product. After derivatization using acetylacetone and 2,4-dinitrophenylhydrazine (2,4-DNPH), formaldehyde is analyzed by spectrophotometer and high-performance liquid chromatography (HPLC). Validation of the three test methods was performed on tissue, diaper lining and waterproof layer, and panty liner products. The results of linearity (R²), limit of detection (LOD), limit of quantification (LOQ), recovery rate (%) and reproducibility (%), showed that all three methods are suitable for analyzing formaldehyde in hygiene products. After derivatization with 2,4-DNPH and cetylacetone, formaldehyde was analyzed at 0, 3, 6, 9, 24 and 48 hours by HPLC. Formaldehyde derivatized with 2,4-DNPH showed no statistically significant change in formaldehyde peak area over time (P>0.05). But, acetylacetone-derivatizated formaldehyde showed a negative correlation coefficient (r) over time (P<0.01). We investigated the residual amounts of formaldehyde in 205 hygiene products distributed in Busan. Among 74 disposable diaper products tested, 73 had low concentrations of formaldehyde (0.13-29.87 mg/kg). Moreover, formaldehyde was not detected in any of 78 tissue, 27 disposable paper towel, 12 disposable dishcloth, 7 paper cup, one brand of paper straw and 6 disposable napkin products.

• Journal of fish pathology
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• v.24 no.1
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• pp.39-45
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• 2011

The specific antibody response of olive flounder, Paralichthys olivaceus to different water temperature were tested by enzyme-linked immunosorbent assay (ELISA). In the rearing temperature of $15^{\circ}C$, first anti-bovine serum albumin (BSA) antibody titer was appeared after 14 days of immunization, whereas 24~48 days post-immunization (PI) resulted maximum antibody titer in all 5 experimental fish with optical density (OD) values 1.94~3.04. At the end of the experiment (84 days), 0.03~1.28 OD values were observed. In the rearing temperature of $12{\sim}13^{\circ}C$, first antibody titer was found 28 days PI in 2 out of 5 fish. Three fish shown high OD titer (1.88~2.68) between 56 and 70 days and OD values of 0.49 to 2.35 were observed at 84 days. However, the anti-BSA antibodies of two fish showed less than 0.8 OD values until 84 days. In the rearing temperature of $10^{\circ}C$, specific antibody appeared at 56 days, maximum antibody titer was observed at 70 days in 2 out of 5 fish (OD values: 1.37~1.53) and 1.00 to 1.11 OD values were observed at 84 days. Rest 3 fish showed OD values of 0.12 to 0.68 much below to that of other 2 fish, throughout the experimental period. In conclusion, specific antibody response of olive flounder at high temperature was much faster, higher and longer than that at lower temperature.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.6
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• pp.507-511
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• 2004

This research was carried out to offer the basic informations about new varietal breeding for specific use and physiological characteristics through investigation of detection, content variation and color difference of anthocyanin individual pigments within seed coats in domestic black soybean. The seed of thirteen cultivars such as Geomjeongkong 1, Geomjeongkong 2, Seonheugkong, Tawonkong, Ilpumgeomjeongkong, Geomjeongolkong, Cheongjakong, Jinju 1, Heugcheongkong, Juinunikong-Y, Juinunikong-G, Geomjeongkong 3, Geomjeongkong 4 was tested. C3G (cyanidin-3-glucoside) was detected in only Geomjeongkong 1 and Seonheugkong but D3G (delphinidin-3-glucoside) and C3G were found in Heugcheongkong. The rest cultivars that there were three anthocyanins such as D3G, C3G, and Pt3G (petunidin-3-glucoside). Anthocyanin content of tested cultivars showed a high variation. The ranges of D3G, C3G, Pt3G, and TA (total anthocyanin) contents were $0.55\~2.63mg/g,\;2.77\~8.38mg/g,\;0.38\~5.65mg/g,\;and\;3.32\~16.92mg/g$, respectively. These contents showed variation among cultivars as well as variation between two years, 2001-2002. As a result of variation of anthocyanin color difference, the ranges of L (lightness), a (redness), and b (yellowness) as Hunter's value were $34.09\~42.89,\;12.77\!22.85,\;and\;5.36\~12.10$, respectively, and these color differences showed variation among cultivars and also variation between two years, 2001-2002. D3G, C3G, Pt3G, and TA showed reciprocally a positive correlation being representive of high significance.

• Korean Journal of Biological Psychiatry
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• v.4 no.1
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• pp.84-94
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• 1997

This study was done to examine changes of plasma homovanillic acid(HVA), 5-hydroxyindoleacetic acid(5-HIAA), and HVA/5-HIAA ratio during an 8-week clozapine trial and to investigate the relationship between the plasma monoamine metabolites and treatment responses. Twenty-seven chronic schizophrenic patiens were treated for 8 weeks with clozapine. The psychopathology was assessed at baseline just clozapine trial and then every 2 weeks until the end of 8-week clozapine treatment using the Positive and Negative Syndrome Scale(PANSS) and the Clinical Global Impression scale(CGI). The plasma HVA and 5-HIAA levels were measured also biweekly using high preformance liquid chromatography with electrochemical detection method. Plasma HVA and 5-HIAA levels were significantly decreased during a 8-week clozapine treatment, although plasma HVA/5-HIAA ratio showed no significant change. The changes of plasma HVA levels were in significant correlations with the changes of PANSS positive scores, of general psychophathology scores, and changes of total socres. The changes of plasma 5-HIAA levels were in signfificant correlations with the changes of PANSS negative scores. But the changes of plasma HVA/5-HIAA ratio had no significant correlation with any PANSS subscale score changes. 48% of the patients treated with clozapine was categorized as responders, who showed at least a 20% decrease in PANSS total socre and a CGI severity score of mildly ill or less(${\leq}3$) at the end pint of the study. The baseline plasma HVA levels and HVA/5-HIAA ratio were significantly higher in responders(N=13) than in nonresponders (N=14). But no significant difference in baseline levels of plasma 5-HIAA was found between responders and nonresponders. At the end point of the study, there was significant difference in the change of plasma HVA between responders(40.3% decrement) and nonresponders(3.1% increment). But no signficant differences in the change of plasma 5-HIAA and the change of plasma HVA/5-HIAA ratio between responders and nonresponders were observed. These results suggest that the antipsychotic effect of clozapine on positive symptoms may be associated with dopaminergic blocking activity, and that on negative symptoms may be associated with serotonergic blocking activity. The baseline plasma HVA levels and the change of HVA levels from baseline may be useful predictors of treatment response with clozapine.

• Korean Journal of Food Science and Technology
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• v.39 no.2
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• pp.114-121
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• 2007

The purpose of this study was to investigate 253 kinds of pesticide residues in 58 commercial dried agricultural products in Seoul. The determinations of the pesticide residues were performed using multiresidue methods and were carried out by a gas chromatography-nitrogen phosphorus detector (GC-NPD), an electron capture detector ($GC-{\mu}ECD$), a mass spectrometry detector (GC-MSD) and high performance liquid chromatography-ultraviolet detector (HPLC-UV), and a fluorescence detector (HPLC-FLD). The pesticide residue detection rate in the commercial dried agricultural products was 24.1% (14 of 58 samples). Twelve pesticide residues without maximum residue limits (MRLs) were detected. In the vegetable groups, the frequency of pesticide residues was found to be in the increasing order of dried fruiting vegetables > dried leafy vegetables > dried stalk and stem vegetables. The pesticides used on dried red pepper in the dried fruiting vegetables were varied (7 kinds) and numerous (4 of 8 samples). The pesticide types detected in the commercial dried agricultural products were in the order of pyrethroid > organochloride > organophosphorus and insecticide > fungicide > herbicide ${\cdot}$ nematicide. The primary pyrethroid pesticide detected was cypermethrin. According to the producing areas of products, large numbers of pesticide residues were found in the order of Korea, China, North Korea, USA, and Vietnam.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.2
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• pp.190-196
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• 2010

Purpose: This study was undertaken to investigate the feasibility of using automated liquid-handling systems equipped with reusable fixed tips in Radioimmunoassays and to demonstrate that the use of an automated pipetting instrument can decrease in the typical daily workload. Materials and Methods: The precisions of the automated pipettor and the manual pipettor were determined gravimetrically (n=30). A total of 30 specimens for HBs Ag were repeatedly pipetted (three replicates) with the automated pipettor and then retested. PSA samples were simultaneously pipetted with either the automated pipettor or the manual pipettor and then analyzed (n=40). Sample carryover test assessed for CA19-9, AFP and HCG when the automated pipettor was used. Pipetting speed of the automated pipettor and the manual pipettor were compared by evaluation of each workload. Results: The precisions coefficients of variation (CV) were 2.1% for the automated pipettor and 1.6% for manual pipettor. The mean cpm and CV for each group of replicates were 41,203 cpm and 3.7% for HBs Ag positive specimens, and 99 cpm and 7.9% for HBs Ag negative specimens, respectively. PSA results showed no significant differences between automated pipettor and manual pipettor (p=0.15, r=0.999). Carryover for CA19-9, AFP and HCG analytes was <0.1 ppm or below the assay limit of detection. Pipetting speed was significantly improved by using the automated instrument. Conclusion: There was no evidence that the use of an automated pipettor adversely affected any of the performance characteristics of the assay. Indeed, routine use of the Tecan automated pipettor has resulted in a decrease in the typical daily workload.