• Bulletin of the Korean Chemical Society
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• v.33 no.2
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• pp.559-563
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• 2012

An analytical method for the simultaneous determination of veterinary medicines (amprolium and decoquinate) in cattle and chicken's muscle by HPLC/UV-vis was established. Samples were extracted by a HLB (Hydrophilic-Liphophilic Balance) cartridge with acetonitrile and methanol. Prior to HPLC injection, a mixture solvent (Water:MeOH, 1:1) was utilized as a reconstitution solvent. Chromatographic separation was achieved with a C18 column ($250{\times}4.6mm$, $5{\mu}m$) using gradient elution with 20 mM HFBA and MeOH:ACN (1:1.8). The calibration curves from the spiked blank matrix showed good linearity (above $r^2$=0.997) in the concentration range of $0.13-12.0mg\;kg^{-1}$. The relative recovery (accuracy) and limit of quantitation (LOQ) were in the range of 78.5-107.1% and $0.13-0.42mg\;kg^{-1}$, respectively. The developed method can be used to determine under the MRL (Maximum Residue Limits) levels of veterinary medicines in animal tissues.

• Environmental Engineering Research
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• v.22 no.3
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• pp.245-254
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• 2017

This study investigates methyl orange (MO) degradation by an ultrasonically dispersed nano-metallic particle (NMP) assisted advanced Fenton process. The NMPs were synthesized from the leachate of automobile-shredder residue. X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy were performed for the prepared NMPs. Various parameters, such as the effects of the NMP dosage, the pH value of the solution, the initial concentration of MO, and the amount of $H_2O_2$ on the degradation efficiency of MO were studied. The MO degradation efficiency could be increased by approximately 100% by increasing the dosages of the NMPs and $H_2O_2$ to certain limits, after which in both cases the degradation efficiency was reduced when an excess amount was added. The MO degradation efficiency was found to be 100% at pH 2.0 and 2.5 with the 10 mg/L of initial concentration of the MO. The degradation of MO by ultrasonically dispersed NMPs was appropriate with the pseudo-first-order kinetics.

• Journal of Environmental Science International
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• v.18 no.12
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• pp.1369-1381
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• 2009

The simultaneous determination of residual pesticides was developed using a gas chromatography. In this study, a simple and reliable methodology was improved to detect 175 kinds of residual pesticides by a liquid-liquid extraction procedure, followed by chromatographic analysis by gas chromatography. The 175 kinds of residual pesticides was classified into 4 groups according to the chemical structure, column type, resolution and sensitivity. The soybean sample selected for recovery experiment was not detected any pesticides. The recovery rates were ranged from 70.6% to 119.7% in most pesticides. The relative standard deviation (RSD 0.3~5.6%) was lower than 5.6% in all cases. The limits of detection (LOD) was lower than the maximum residue levels established by Korean legislations. The method has been successfully applied to the analysis of approximately 130 real samples.

• The Korean Journal of Food And Nutrition
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• v.13 no.2
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• pp.164-170
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• 2000

10 carbamate pesticides were surveyed in domestic and imported green peas, beans, red beans from March 1999 through December 1999. Samples were collected from Gwangju, Mokpo, Suncheon and Yosoo grain markets. This study was performed by post-column ο-phthalaldehyde and 2-mercaptoethanol prior to HPCL fluorophore detection. Pesticides were found in 14 of 80 samples(17.5%). The kinds of pesticide detected in green peas were methomyl, MTMC, carbaryl, those in sesames were oxamyl, carbofuran, carbaryl, 1-naphthol, MIPC, those in beans were oxamyl, MTMC, carbaryl and those in red beans were MTMC, carbaryl. The range of residues detected in green peas, sesames, beans and red beans were 0.002∼0.025ppm, 0.001∼0.469ppm, 0.005∼0.356ppm and 0.017∼0.125ppm, respectively. The most frequently detected pesticides were MTMC(6 times) and carbaryl(5 times), while aldicarb, PHC and BPMC were no detected in all samples. Detection frequencies of carbamate pesticides in imported crops were higher than those in domestic ones except red beans. Only one result of oxamyl residues determined in imported bean was higher than the proposed maximum residue limits of Codex, which was 0.356ppm.

• Korean Journal of Food Science and Technology
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• v.27 no.4
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• pp.618-624
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• 1995

In order to evaluate the acceptability of Korea and Codex maximum residue limits (MRLs), theoretical maximum daily intake (TMDI) by Korean population was calculated from MRL and food factor and compared with acceptable daily intake (ADI). The percent ratio of TMDI to ADI for 105 pesticides whose MRL was established in Korea was mostly below 80% and 13 pesticides exceeded the ADI. Among 82 pesticides with Codex MRL, 20 items exceeded the ADI. The main causes of exceeding the ADI according to Korea or Codex MRLs were pointed out for 22 items and it was needed to set measures to assure a safety margin.

• Korean Journal of Veterinary Service
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• v.34 no.3
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• pp.285-289
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• 2011

This study was conducted to determine the content of non-steroidal anti-inflammatory drugs (NSAIDs) in meats available on the Korean markets. The analysis was carried out using following conditions; C18 column ($100{\times}2.1$ mm, 1.7 ${\mu}m$), mobile phase composed of DW (containing 0.1% formic acid): acetonitrile (containing 0.1% formic acid), binary pump at a flow rate of 0.3 ml/min and 5 ${\mu}l$ of injection volume, MS/MS detector with ESI positive mode. The calibration range of five NSAIDs showed linearity ($r^2{\geq}0.99$) at concentration range of 3.125~200 ${\mu}g$/kg. The recoveries in fortified muscle more than 78.7~100.3%. The detection limits for meloxicam, ketoprofen, flunixin, carprofen and tolfenamic acid were 3.5, 1.6, 1.7, 9.8 and 4.8 ${\mu}g$/kg, respectively. We also monitored NSAIDs residue in cattle muscle 51 samples. The test results, NSAIDs were all not founded.

• Korean Journal of Veterinary Service
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• v.31 no.1
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• pp.129-135
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• 2008

A total of 3,943 samples (beef 698, pork 2,178 and chicken 1,067)were collected from slaughter houses in Daegu from January to December 2006 for analysis of antimicrobial residues. The results were also comparatively analyzed with those carried out from 16 veterinary service laboratories nationwide as a part of national residue program in 2006. The samples from 11 farms (cattle 2, pig 9) were found to exceed the legal limit. Among them 5 were classified as tetracyclines, 3 as $\beta$-lactams, 2 as sulfonamides and 1 as quinolone. Nationally a total of 222 farms (241 cases) were found to violate the residual limits, of which 47.3% were detected by screening test, followed by surveillance (38.3%). Failure to observe withholding periods of antimicrobial drugs after treatment was the most significant cause of the non-compliance.

• Korean Journal of Environmental Agriculture
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• v.34 no.4
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• pp.303-308
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• 2015

BACKGROUND: Recently, various rice by milling degree is sold for health and taste. To provide safe food to consumers, it is need to know the change of heavy metal contents according to milling degree of rice.METHODS AND RESULTS: This study was to investigate residual the levels of cadmium (Cd), lead (Pb), copper (Cu) and zinc (Zn) as stated in the milling degree of the rice contaminated Cd and Pb from 2011 to 2012 in Chungcheongnam-do. Rice samples exceeded the maximum residue limits (MRL) of Cd and Pb were milled by five degrees (0.0, 2.45, 8.02, 10.48, 15.09%). Milled rice was digested by microwave method, and analyzed heavy metal contents using ICP-OES. Recovery ratios of 4 heavy metals such as Cd, Pb, Cu and Zn were ranged for 79.7-98.9%, and limits of detection (LOD) and limits of quantitation (LOQ) were fulfilled with the normal analytical standards. Concentrations of Cd, Pb, Cu and Zn were ranged 0.416-0.433 mg/kg, 0.183-0.26 mg/kg, 3.639- 3.882 mg/kg and 16.868-19.801 mg/kg, respectively.CONCLUSION: From these results, conforming with increase of milling degree of rice, Cd, Pb, Cu, and Zn contents tended to decrease. The contents of heavy metals were decreased 3.1% in Cd, 29.3% in Pb, 6.4% in Cu and 15.1% in Zn, in according to the highest milling degree of 15.09%.

• The Korean Journal of Pesticide Science
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• v.12 no.1
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• pp.67-73
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• 2008

The dissipation patterns of a boscalid in cucumber under greenhouse condition was investigated to establish pre-harvest residue limit (PHRL) and biological half-life. Initial concentration of boscalid in cucumber at standard application rate was $7.29\;mg\;kg^{-1}$ and decreased to $0.04\;mg\;kg^{-1}$ after 15 days with half-life of 1.9 day, while the initial concentration was $14.69\;mg\;kg^{-1}$ and decreased to $0.11\;mg\;kg^{-1}$ after same period with half lift of 2.0 day at double application rate. PHRL was suggested by prediction curve derived from the decay curve of boscalid at double rate treatment. For example, $10.39\;mg\;kg^{-1}$ was calculated for 10 days before harvest, and $1.73\;mg\;kg^{-1}$ for 5 days. Dilution effect was major factor far the decrease of boscalid residue due to fast increasement of weight of cucumber during cultivation. Final residues level of boscalid was predicted based on the dissipation curve and guideline on safe use, when boscalid was used to control powdery mildew and gray mold. At standard rate application, $1.26\;mg\;kg^{-1}$ and $1.33\;mg\;kg^{-1}$ were calculated as final residue levels for control powdery mildew and gray mold, respectively, which are above the MRL(Meximum Residue Limit).

• Korean Journal of Food Science and Technology
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• v.42 no.1
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• pp.1-7
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• 2010

To revise the dithiocarbamates residue analysis method and survey the residues in agricultural products that were treated with these fungicides in Korea, we purchased 20 types of foodstuffs (rice, potato, cabbage, apple etc.) from markets in five major cities. 236 samples of the purchased foodstuffs were then analyzed for the presence of dithiocarbamates by HPLC/UV and HPLC/APCI-MS. The $R^2$, LOD and LOQ in the range of 0.5-107.3 mg/L were as follows: DCC: y=174.34x+18.315, $R^2=0.9999$, 0.01 mg/L, and 0.04 mg/L; EBDC: y=227.38x-14.715, $R^2=1.0000$, 0.01 mg/L and 0.02 mg/L; PBDC: y=38.46x-21.412, $R^2=0.9999$, 0.04 mg/L, and 0.1 mg/L; ETU: y=52.752x-4.4819, $R^2=0.9998$, 0.02 mg/L and 0.03 mg/L; PTU: y=128.28x+4.4624, $R^2=0.9998$, 0.02 mg/L, and 0.04 mg/L. The levels of DDC, EBDC, PBDC, ETU and PTU in 20 agricultural products fortified to 10.0-107.3 mg/L ranged from 61.7-117.5%, 65.3-110.1%, 61.5-109.6%, 69.3-116.3% and 70.2-97.2%, respectively. Overall, dithiocarbamates were detected in 100 samples and the detection ratio was 42.4%. Among these, only 3 samples (1.3%) of Lycii fructus had residue levels that were above the action limits, while the remaining samples (233 samples) contained levels of dithiocarbamates below the detection limit or below the Korea MRLs (Maximum Residue Limits).