• Food Science of Animal Resources
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• v.18 no.1
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• pp.50-56
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• 1998

Scanning electron microscopic appearance of infant milk formula indicated that mostly agglomerate with few or more diverse number of particles and also apple like as well as typical feature of drying in raw milk. Small particle of infant milk formula become agglomerate progressively. Some sample represent crystalline rectangular among the globular agglomerates which seem to be a different composites or those of solubility. Some sample showed the irregular porosity at central sec-scanning electron microscopic study between Korea and European products.

• 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.19 no.1
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• pp.39-45
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• 1996

Sulfonamides are widely used to treat mastitis of cattle in field. The study was carried out to analyze sulfonamid residues In raw milk from south Kyeonggi area. The milk sample was deproteinated with acetone and defatted with hexane. The residual sulfonamides were extracted with ethylacetate, concentrated under vaccum, reconstituted with the acetate buffer-methanol mixture, reacted with fluorescamine, and then analyzed by HPLC-fluorescence detector(EX. 39nm, Em. 495nm) with methanol : acetate buffer system(3/2, v /v) as a mobile phase. The results analyzed by Thin layer chromatography and High performance liquid chromatography were summarized as follows. 1. A total of 24 cases out of 478 raw milk samples(5.0%) collected during April and May showed positive reaction to sulfonamide residues. Among 24 positive reactors, 9 cases were positive to sulfanilamides(32.1%), 8 cases were positive to sulfathiazoles(28.6%) and 5 cases were positive to sulfamonomthoxines (7.9%) , respectively. 2. During July and August, 31 cases out of 464 raw milk samples(6.7%) showed positive re action to sulfonamide residues. Among them S cases were positive to sulfanilamides, 5 cases sulfathiazoles and 5 cases sulfamonomethoxines(16.1%), respectively.

• Korean Journal of Veterinary Service
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• v.14 no.1
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• pp.63-69
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• 1991

Antibiotic residues of raw milks collected in Anyang area were tested by TTC-reduction test, EEC-4plate method and TLC(SOS-kit ) method to improve and monitor the quality of milk. Antibiotic substances were not detected from 100 raw milk samples, but sulfamethazine was detected from only one sample(1.3PPM) by SOS test. Unclassified anti-microbic substances were detected from 22 samples by EEC-4 plate method. EEC-4 plate test was useful to categorize the species of antibacterial substances and SOS test was useful to detect the sulfamethazine field screening test.

• Journal of the korean veterinary medical association
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• v.15 no.3
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• pp.143-148
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• 1979

A total of 360 Staphylococcus isolates from 26 raw cow milk sample in milk plants of Jeonju district during Octover 1977, identified by $7.5\%$ salt resistant reaction and other biological properties. Antibiotic sensitivity test was also perfor

• Korean Journal of Veterinary Service
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• v.16 no.1
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• pp.11-19
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• 1993

This experiment was carried out to detect the residues of sulfonamides in raw milk. Raw milks which does not contain sulfonamides was collected from one of the farm and fortified with 5 sulfonamides (sulfamerazine, sulfamethazine, sulfamonomethoxine, sulfadimethoxine, sulfaqinoxaline). The sulfonamides in the fortified sample were extracted and detected by High Performance Liquid Chromatography. UV /vis detector was used in this experiment. The results obtained were summarized as follows : 1. Chloroform was good as a extracting solution. 2. 15.5% methanol in PDP as a mobile phase solution was best detective condition for SMR, SMT, SMM. But for SDM and SQN the best condition was 23% methanol. 3. The detectable limits of SMR, SMT, SMM were 2ppb. but SDM and SQN were 20ppb because of delayed retention time and relatively low recovery rate. 4. The peaks of SMR, SMT, SMM and SDM were erected at baseline and the apexes were sharp but SQN was round shape.

• Journal of Microbiology and Biotechnology
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• v.16 no.8
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• pp.1229-1235
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• 2006

A lab-on-a-chip (LoC) was designed for simultaneous monitoring of microorganisms, antibiotic residues, somatic cells, and pH in raw milk. The LoC was fabricated from polydimethylsiloxane (PDMS) using microelectromechanical system (MEMS) technology, which consisted of two parts; a protein array and microchannel. The protein array was fabricated by immobilizing five types of antibodies corresponding to two microorganisms, two antibiotic residues, and somatic cells. A sol-gel film was deposited on a glass substrate to immobilize the antibodies. The target analytes in raw milk could be bound with the corresponding antibody by an immunoreaction, and the antigen-antibody complex was detected using fluorescence microscopy. SNARF-dextran was used as a pH indicator, and the SNARF-entrapped hydrogel was attached to the microchannel in the chip. After injecting the milk sample into the channel, the pH was measured by monitoring the change in fluorescence intensity by fluorescence microscopy. The on-chip simultaneous assay of two microorganisms (E. coli O157:H7 and Streptococcus agalactiae), two antibiotic residues (penicillin G and dihydrostreptomycin), and neutrophils was successfully accomplished using the proposed LoC system.

• Korean Journal of Veterinary Research
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• v.39 no.3
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• pp.609-615
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• 1999

From July of 1997 to June of 1998, total 279 raw milk samples over withdrawal period after mastitis treatment from dairy farms located in the provinces of Kyonggi and Choongchung were collected to test drug residues. Each sample was tested by TTC- II test and Delvotest SP. Among the total 152 raw milk samples of cow treated by ${\beta}$-lactams, 32 samples(21.2%) were positive on the Delvotest and 15 samples(9.9%) showed positive on the TTC-II test. Also, from the total 37 samples treated by sulfonamides, 5 samples(13.5%) were positive on the Delvotest and 3 samples(8.1%) showed positive on the TTC-II test. For the total 55 raw milk samples of cow treated by tetracyclines, 9 samples(16.4%) were positive on the Delvotest and 5 samples(9.1%) showed positive on the TTC-II test. In addition, from the total 35 samples treated by aminoglycosides, 7 samples(20.0%) were positive on the Delvotest and 5 samples(14.3%) showed positive on the TTC-II test. Our study shows that it is possible that drugs are to be detected by the drug residues test of an individual raw milk even over the withdrawal period after mastitis treatment and the raw milk of bulk tank.

• Journal of Microbiology
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• v.40 no.2
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• pp.170-172
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• 2002

To determine the occurrence of vancomycin-resistant Enterococci in a raw milk sample, raw milk samples were examined for a period of 6 months. Enterococci were isolated directly from Enterococcal selective agar plates supplemented with 2 mg of vancomycin per liter, Nineteen strains were selected and identified by applying the Vitek system. To determine resistance patterns, 19 isolates were tested with vancomycin and teicoplanin. Vancomycin-resistant Enterococci were genotyped by using a PCR analysis and 5 out of 19 isolates were of the VanC type.

• Food Science of Animal Resources
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• v.29 no.4
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• pp.482-486
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• 2009

The aim of this study was to optimize a simple, fast, and economical analysis procedure for the determination of 16 different pesticides in raw milk via GC/MSD. Analyses were performed via gas chromatography with electron impact mass spectrometric detection in the selected ion monitoring mode (GC/MSD-SIM) using Pentachloronitrobenzene as the internal standard. The modified sample preparation methodology was based on the Pesticide Analytical Manual (PAM) of the FDA concerning fat extraction, ACN-ether partitioning, and clean-up of the Sep-Pak florisil cartridge. The modified methodology for the determination of the 16 pesticides was validated. The range of LOQs of the 16 pesticides was likely three times lower than their Maximum Residence Levels (MRLs). The recoveries of most of the pesticides were acceptable at the fortification levels of 0.5 and 1.0 ${\mu}g/mL$ and their RSD (%) level was less than 20%. None of the 16 pesticides were detected in the selected raw milk samples.