• Journal of Food Hygiene and Safety
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• v.12 no.1
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• pp.71-77
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• 1997

Sulfonamides, a therapeutically important group of antimicrobial drugs, are widely used to treat and prevent the acute systemic and skin infections in dairy cattle. They also pose an economic hazard through inhibition of growth of dairy starter cultures. This study was carried out to compare four screening methods for detection of sulfamethazine in milk and determine the positive milk sample by HPLC method. Sulfamethazine was used to spike at five levels of sulfamethazine. The Lac-Tek test and CharmII test were also consistent better than TTCII test and Delvo SP test in sulfamethazine detection. Analysis probabilities of obtaining a positive response with TTCII test and Delvo SP test assay at 50 ppb sulfamethazine level in milk samples were only 14%, 42% each. Whereas using the Lac-Tek test and CharmII test would have resulted in 100% identification of the five levels. Determination of sufamethazine using the HPLC method in the spiked milk were 10.64, 19.30, 30.76,38.83 and 50.23 ppb, respectively.

• Korean Journal of Veterinary Service
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• v.27 no.1
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• pp.17-29
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• 2004

A multiresidual analysis was performed to determine 12 sulfonamides(sulfacetamide, sulfadiazine, sulfisomidine, sulfathiazole, sulfapyridine, sulfamerazine, sulfamethazine, sulfamonomethoxine, sulfisoxazole, sulfamethoxazole, sulfaquinoxaline, and sulfadimethoxine) in beef and pork simultaneously. The multiresidual analysis for the sulfonamides currently used was able to analyze 5 kinds of sulfonamides at the same time. The method of this 12 sulfonamides multiresidual analysis in this study was matrix solid-phase dispersion(MSPD) by high performance liquid chromatography (HPLC) and liquid chromatography mass spectrometry (LC/MS). The recovery rate of the materials was measured by MSPD method with 3 different extraction solvents; Dichloromethane, DCM: Ethylacetate(3:1), DCM:EA(9:1). Also, samples (84 beef and 205 pork samples) which were positive by EEC-4 plate test from 2001 to 2003 were tested to investigate the kinds of sulfonamides using HPLC. The results from the study were as follows; 1. The recovery rate of the materials was measured by MSPD method with 3 different extraction solvents; Dichloromethane, DCM:Ethylacetate(3:1), DCM:EA(9:1). The method of extraction solvent with DCM:ethyl acetate(9:1) was the most excellent(87.7∼99.3%) in separation and reappearance. 2. In the LC/MS analysis. of sulfonamides, signal to noise ratio was showed relatively high in the positive mode and special ion in the quality analysis was determined via [M+H]$\^$+/ and m/z 156. A spectrum of sulfonamides was showed from all 12 sulfonamides. 3. The samples positive by the EEC-4 plate, a screening test method, were categorized by sulfonamides through Charm II and confirmed the kinds of sulfonamides through HPLC. 1) Among 84 beef samples positive by EEC-4 plate, 20 samples were positive by Charm II and identified as 7 sulfamethazine, 9 sulfadimethoxine, 1 sulfamonomethoxine and 3 unknown status. 2) Among 205 pork samples positive by EEC-4 plate, 42 samples were positive by Charm II and identified as 19 sulfamethazine, 1 sulfadimethoxine, 4 sulfamonomethoxine and 5 unknown status.

• Korean Journal of Veterinary Service
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• v.26 no.2
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• pp.113-119
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• 2003

This study was carried out to compare the antibiotic residues in the muscles of cattle and pigs from slaughter-houses in Seoul from 2000 to 2002 by EEC-4-plate, Charm II and HPLC methods. The results were summarized as follows; 1. Residual materials were detected from 41 samples(0.6%) by EEC-4-plate method from random sampling and 38 samples(12%) by Charm II method from directed sampling. 2. Violation rates were 0.3% by monitoring and 4.7% by surveillance program. 3. The 35 samples were classified as tetracyclines 30(86%), sulfonamides 4(11%), ${\beta}$-lactams 1(3%) and two samples simultaneously determined oxyteracycline plus sulfadimetoxine, and sulfamerazine plus sulfadimetoxine. 4. The highest residual concentration(ppm) of chlortetracycline, oxytetracyline, sulfamethazine, sufadimetoxine and penicillin were 0.5, 12.0, 6.4, 2.6 and 0.44, respectively.

• Korean Journal of Veterinary Service
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• v.20 no.1
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• pp.79-93
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• 1997

The sulfonamide is one of potentiative antimicrobial agents which is being used widely in veterinary medicine for control of several animal diseases such as mastitis as well as for promotion of growth. However, the misusages of sulfonamides in food producing animals, especially cattle produce several considerable problems in human health caused from residues of this antibiotic in milk product. To determine the most effective analytical methods for residual sulfonamides in raw milk, this study was performed comparatively using by some applicable screening detecting method such as TTC, Charm II test (sulfonamides), and Lactek tests (sulfamethazine kit). The positive result from screening tests was confirmed by HPLC method. Milk samples (540 raw milks) were collected from dairy farms. Results of this study are summariezed as follorrs ; 1. All samples (540 raw milks) showed negative response from TTC test, however, 18 raw milks of those samples responded positively to Charm II test. 2. By Lactek test, residual sulfamethazine was detected from 4 raw milks. Fifteen raw milks of 18 samples which were classified as positive one by Charm II test, showed positive response 3. Retention time of sulfonamides added at the level of 100ppb into sklm milk was ranged from 1.55 minute to 23.3 minute. Recovery rates of sulfonamides were variable from 6.7% upto 94.2% depended on the types of sulfonamlde. 4. Single type of sulfonamides was detected from 10 raw milk samples, 2 types of sulfonamides from 3 samples and 3 types from 2 raw milks by HPLC. 5. Sulfonamides was detected in this study were 5 types : 11 samples for sulfisomidine, 5 samples for sulfamethazine, 3 samples for sulfadlmethoxine, 2 samples for sulfathiazole and 1 sample for sulfadiazine. 6. The highest levels of residual sulfonamides was 210.3 ppb of sulfamethazine but the lowest concentration of residue was 2.2 ppb of sulfamethazine and sulfisomidine, respectively. Number of samples detected positively in this experiment were belows : above 100 ppb for 1 sample (4.5%) (sulfamethazine), 50~100 ppb for 4 samples (18.1%) (each 2 samples for sulfamethazine and sulfisomidine, respectively), 25~50 ppb for 6 samples (27.1%) (2 sulfisomidine, each 1 sample for sulfadiazine, sulfadimethoxine, sulfamethazine and sulfathiazole, respectively), 10~25ppb for 3 samples (13.7%) (3 sulfisomidine), and below 10ppb for 8 samples (36.4%) (4 sulfisomidine, 2 sulfadimethoxine and each 1 for sulfamethazine and sulfathiazole).

• Korean Journal of Veterinary Service
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• v.20 no.4
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• pp.339-348
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• 1997

The purpose of the survey were determined the residual antibiotics and tetracyclines in beef(n=1,364), pork(n=2,817) and chickens(n=1,921) by the EEC 4-plate method, Charm IIand HPLC. The results were summarized as follows ; 1. The recovery rates in spiked samples were 98.8-107.2% for oxytetracycline(OTC), 33.2-48.6% for tetracycline(TC) and 64.1-72.3% for chlortetracycline(CTC) at 0.05-0.1ppm by HPLC using MSPD. 2. Residues of antibiotic were detected from 10 beef(0.75%) and 36 pork(1.31%) by EEC 4-plate method. In case of chickens were not detected. 3. Twenty-eight from 46 positive samples by the EEC 4-plate method were classified as TCs(60.9 %) by Charm II and TC of 12 samples were detected by HPLC. 4. Ten samples were detected levels of OTC ranging from 0.035 to 0.635 ppm and 3 samples were levels of CTC ranging from 0.066 to 0.150 ppm. OTC and CTC levels in 3 beef and 4 pork samples were exceeded the current tolerance level of 0.1 ppm.

• Korean Journal of Veterinary Service
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• v.28 no.3
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• pp.203-213
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• 2005

Oxytetracycline, tetracycline, chlortetracycline and doxycycline in honey were separated by solid phase extraction (SPE) and determined with high performance liquid chromatography (HPLC) with UV/Visible detector. Analysis was carried out using following conditions: XTerra $C_8$ column $(3.9\times150mm\;i.d. 5{\mu}m)$, mobile phase composed of 0.01M oxalic acid : methanol : acetonitrile (820 : 80 : 100, v/v/v), isocratic pump at a flow rate of 0.9 ml/min. and $50{\mu}l$ of injection volume, UV/Visible detector with wavelength of 360nm. The calibration curves of four tetracyclines showed linearity $(\gamma^2>0.999)$ at concentration range of $100\~1,000 ng/ml$. The recoveries in fortified honey represented more than $70\%$ with low coefficient of variation $(<10\%)$ for concentration range of four tetracyclines. The detection limits for oxytetracycline, tetracycline, chlortetracycline and doxycycline were 13.8, 14.6, 26.2 and 24.9ng/g in acacia honey. respectively. We also monitored tetracyclines residue in domestic honey [n : 38, acacia (20), wild flower (18) ] and foreign honey [n=22, legally distributed (13), illegally distributed (9)] using modified Charm II screening and HPLC confirmation methods. Seven of the 60 samples $(11.7\%)$ were suspect positive using modified Charm II screening test. Chlortetracycline residue was found in one foreign honey (illegally distributed) tested at concentrations of 0.22 ppm. Conclusively, for more effective control of tetracyclines used in beekeeping should be further survey for residues in honey and also national guidelines (maximum residue limit : MRL) and methods should be obligatory.

• The korean journal of orthodontics
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• v.35 no.3 s.110
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• pp.207-215
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• 2005

This study was performed to evaluate clinical practicality of the rebonding method with flowable resin without the removal of the residual resin on the debonded theeth and debonded bracket base after debonding. The samples of the control group (group I) were rebonded with Transbond XT using the usual rebonding method after the residual resin was removed. At experimental group, the brackets were rebonded with Transbond XT(group II) and CharmFil Flow (group III) without removal of residual resin which is the possibility becoming the index (or rebonding to similar position With initial bonding. The Shear bond Strength of the each group was measured. Patterns of bonding failure were evaluated with modified ARI score. and the shear bond strength according to patterns of bonding failure at experimental group was compared. Between the control group $(6.51\pm1.21MPa)$ and the group II rebonded with Transbond XT $(6.30\pm1.01MPa)$ did not have significantly difference in the shear bond strength (p=0.534), and the shear bond strength of group II was Significantly lower 4han the group III rebonded With CharmFil Flow $(7.29\pm1.54 MPa)$ (P=0.009). At control group, there was not large difference if distribution of bending failure pattern. But at experimental group, bond failure did not occur in interface between the resin-enamel. and bond failure between the resin-bracket, within the resin was distributed similarly. There was not significantly difference in the shear bond strength according to patterns of bonding failure at experimental group (P>0.05) The result of this study showed that the method suggested in this study aid flowable resin as rebonding adhesive could be useful in clinically.

• Ocean Systems Engineering
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• v.13 no.2
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• pp.173-193
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• 2023

Reliable prediction of the motion of FOWT (floating offshore wind turbine) and associated mooring line tension is important in both design and operation/monitoring processes. In the present study, a 5MW OC4 semisubmersible wind turbine is numerically modeled, simulated, and analyzed by the open-source numerical tool, OpenFAST and in-house numerical tool, Charm3D-FAST. Another commercial-level program FASTv8-OrcaFlex is also introduced for comparison for selected cases. The three simulation programs solve the same turbine-floater-mooring coupled dynamics in time domain while there exist minor differences in the details of the program. Both the motions and mooring-line tensions are calculated and compared with the DeepCWind 1/50 scale model-testing results. The system identification between the numerical and physical models is checked through the static-offset test and free-decay test. Then the system motions and mooring tensions are systematically compared among the simulated results and measured values. Reasonably good agreements between the simulation and measurement are demonstrated for (i) white-noise random waves, (ii) typical random waves, and (iii) typical random waves with steady wind. Based on the comparison between numerical results and experimental data, the relative importance and role of the differences in the numerical methodologies of those three programs can be observed and interpreted. These comparative-study results may provide a certain confidence level and some insight of potential variability in motion and tension predictions for future FOWT designs and applications.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.4
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• pp.524-528
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• 2005

The purpose of this study is to investigate the quality characteristic of cholesterol free milk helping the reduction of serum cholesterol. Cholesterol free milk stored at $10\pm1^{\circ}C$ was evaluated with general analysis, stability, cholesterol, microorganism, aflatoxin $M_1$, antibiotic, antibacterial agent, color, and sensory evaluation. Animal fat contents were significant (p<0.05), but normal values. Quality characteristics of alcohol test, freezing point, and somatic cell count were general milk data with stability. Cholesterol content, microorganism, and aflatoxin MI were not detected. Also antibiotic and antibacterial agent residues were not detected by Parallux, Charm II, TTC II, and Eclipse method. Color of CFM1 was significant, while CFM2 was similar with conventional milk. Compared to control milk made by conventional way, QDA scores of color and mouthfeel in CFM1 were significantly different, whereas CFM2 did not show any significant. These Quality characteristic results suggested that health-oriented cholesterol free milk would be made by food additive.

• Food Science and Biotechnology
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• v.16 no.6
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• pp.868-872
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• 2007

The microbiological and chemical identification of antibiotic residues was attempted for livestock and seafood products including pork (n=34), beef (n=34), chicken (n=32), flatfish (n=37), armorclad rockfish (n=36), and sea bream (n=27). The meat (n=100) and seafood (n=100) samples were collected from 9 markets in 5 major Korean cities. Antibiotic substances were identified from the classes of tetracyclines, macrolides, penicillins, aminoglycosides, polyethers, peptides, sulfonamides, quinolones, chlorampenicols, and novobiocins using a microbiological assay, the Charm II test and high performance liquid chromatography (HPLC) with ultra violet (UV) and fluorescence detectors. The results showed that 2 tetracyclines (oxytetracycline and tetracycline) and 3 quinolones (ciprofloxacin, norfloxacin, and enrofloxacin) were detected in 4 samples of flatfish among all 100 seafood samples tested. No antibiotic residues were detected in the 100 livestock product samples tested. The amounts (min-max, mg/kg) of the residual antibiotics were as follows; tetracycline 0.78-0.85, oxytetracycline 0.49-0.74, ciprofloxacin 0.09-0.83, norfloxacin 0.01-0.21, enrofloxacin 0.12-2.98. These data indicate that the total detection rate of antibiotics in livestock and seafood products was approximately 2%.