본 연구는 불법적으로 수산물에 사용될 수 있는 염료 18종에 대한 안전관리 강화를 위해 정량 및 정성 분석이 가능한 LC-MS/MS를 적용하여 검증하기 위해 수행되었다 . 확립된 시험법은 CODEX CAC/GL-71 가이드라인에 따라 직선성, 정밀성 , 정량한계 및 회수율 등을 통해 유효성을 확인하였다 . 대상시료에 1% 아세트산을 함유한 아세토니트릴로 추출 후 C18 과 PSA로 정제하였다 . 본 실험에서 정량한계는 0.002 mg/kg 수준으로 정량한계를 포함한 농도에 따라 검량선을 작성하였고 모두 0.98 이상의 직선성을 확인하였다 . 또한 정확성은 63%-112% 이고, 정밀도는 15% 이하로 재현성이 우수하였다 . 국내 유통 중인 수산물 124 건을 수거하여 개발된 분석법의 적용성 검증과 안전성을 확인하고자 잔류실태조사를 실시 하였고 그 결과 7건이 미량으로 검출 되었고 부적합은 없었다 . 확립된 시험법은 수산물 안전관리에 활용할 수 있을 것으로 사료되는 바이다 .

The aim of the present work was to develop simultaneous methods of quantification of carazolol, azaperone, and azaperol residues in livestock and fishery products using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Samples were extracted from beef, pork, chicken, egg, milk and shrimp using acetonitrile (ACN); while flat fish and eel were extracted using 80% ACN. For purification, ACN saturated n-hexane was used to remove fat composition. The standard calibration curves showed good linearity as correlation coefficients; r 2 was > 0.99. Average recoveries expressed were within the range of 67.9-105% for samples fortified at three different levels (0.5 × MRL, 1 × MRL and 2 × MRL). The correlation coefficient expressed as precision was within the range of 0.55- 7.93%. The limit of quantification (LOQ) was 0.0002-0.002 mg/kg. The proposed analytical method showed high accuracy and acceptable sensitivity based on Codex guideline requirements (CAC/GL71-2009). This method can be used to analyze the residue of carazolol, azaperone, and azaperol in livestock and fishery products.

A liquid chromatographic-tandem mass spectrometric (LC-MS/MS) multi-residue method for simultaneous quantification and identification of 37 anthelmintic veterinary drug residues (including benzimidazoles, macrocyclic lactones, and flukicides, levamisole, pyrantel and niclosamide) in milk has been developed and validated. For sample preparation, we used a simple modification of the QuEChERS (quick, easy, cheap, effective, rugged and safe) method, which was initially developed for analysis of pesticide residues. Anthelmintic residues were extracted into acetonitrile:methanol (9:1, v/v) using sodium chloride to induce liquid-liquid partitioning followed by dispersive solid phase extraction for cleanup. The extract was concentrated into dimethyl sulphoxide, which was used as a keeper to ensure that analytes remain in solution. Using rapid polarity switching in electrospray ionization, a single injection was capable of detecting both positively and negatively charged ions within a 15 min run time. The Limit of detection (LOD) and the Limit of quantification (LOQ) method ranged from 0.1 ng/g to 4.4 ng/g and from 0.3 ng/g to 14.6 ng/g, respectively. Validation of the developed method was based on international guidelines. Average recoveries ranged from 70% to 120%, except for 54.7% at 0.5× MRL (rafoxanide) and 69.0% at 0.5× MRL (closantel). The coefficient of variation for the described method was less than 15% over the range of concentrations studied. The result of the method was verified successfully by participation in a proficiency study for analysis of anthelmintic drugs.

A confirmatory method based on liquid chromatography with tandem mass spectrometry was developed for determination of 12 aminoglycosides in milk. Extraction of aminoglycosides from milk was performed using by liquid extraction using a 10 mM phosphate buffer containing 2% (w/v) trichloroacetic acid, followed by performance of a solid-phase clean-up procedure on a hydrophilic-lipophilic balance solid-phase extraction (HLB SPE). Ion-pair chromatography, using a mixture of 20 mM heptafluorobutyric acid (HFBA) in water and acetonitrile as the mobile phase, was used for retention of aminoglycosides on a reversed-phase C18 column. Mass spectral acquisition was performed in the multiple reaction monitoring mode, selecting two precursor ion>product ion transitions for each target compound. Satisfied recoveries (70.1～109.6%) of all aminoglycosides were demonstrated in spiked milk at three levels from 50 ng/g to 200 ng/g. The coefficients of variation ranged from 3.2% to 14.0%. The limits of quantitation (LOQs) for aminoglycosides ranged from 2.5 ng/g to 40.3 ng/g.

The Korean National Residue Program consists of three sampling plans for domestic and imported foods of animal origin : monitoring, surveillance/enforcement and exploratory testing. Monitoring and surveillance/enforcement testing programs are routinely implemented by 17 Provincial Veterinary Services for domestic products and two regional offices of Animal, Plant and Fisheries Quarantine and Inspection Agency (QIA) for imported products, respectively. The exploratory testing is designed to test substances which are not included in the list of monitoring and enforcement testing programs controlled by headquarter of QIA. In 2010, the exploratory testing was carried out in domestic and imported foods of animal origin for 24 veterinary drugs including florfenicol, clavulanic acid, four quinolones (nalidixic acid, difloxacin, marbofloxacin, orbifloxacin), two anthelmintics (closantel, levamisole), two sedatives (azaperone, carazolol), six glucocorticoids (dexamethasone, betamethasone, flumethasone, prednisone, prednisolone, methylprednisolone), eight non-steroidal anti-inflammatory drugs (phenylbutazone, paracetamol, carprofen, flunixin, ketoprofen, meloxicam, tolfenamic acid, acetylsalicylic acid). In the total of 1,153 domestic samples, only florfenicol was detected from 17 pig muscles at levels of 0.2～614 ng/g. Of 17 positive pig muscles, 16 samples were non-violative and one sample was violative. In the total of 1,065 imported samples, florfenicol was detected at 0.4 ng/g in one pork. Also, flunixin was detected at 22 ng/g in one beef.

Various antimicrobial drug screen tests have been used in order to ensure food safety. However, the conventional screen teats, the Swab Test on Premises(STOP, USA), the Calf Antibiotic and Sulfa Teat(CAST, USA) and the European Economic Community 4-plate Test(FPT, EU) are not sufficiently rapid or sensitive enough to detect low levels of sulfa drugs in meat. We developed a new screen test kit for the determination of the antimicrobial residues in meat called the Bacillus megaterium Disk AssayBmDA). A comparison of BmDA with the older screen tests showed BmDA was as good as the older ones with several advantages. The new test kit is faster-it can be read in 4-6 hours instead of 16-18 hours. Moreover, BmDA can discriminate sulfa drugs from other antimicrobial drugs because p-aminobenzoic acid countacts the inhibiting action of sulfa drugs. Minimum detectable levels of sulfa drugs were significantly improved at the level of 0.025-0.1 ppm compared with the level of 1.0 ppm in FPT. A comparison of BmDA with the older screen tests in HPLC confirmed meat samples exeeded the Korean tolerance value of 0.1 ppm showed BmDA was the most sensitive in the microbiological screen tests. As the microbiological screen tests have already known, a person familiar with simple laboratory techniques should have no difficulty in using it to detect antimicrobial residues in meat. This would be a simple, economic method of antimicrobial residues detection which might be succesfully used by many laboratories.

The European Economic Community four plate test(EEC 4-plate test, FPT, EU) has been used for monitoring antimicrobial drug residues in meat by Local Veterinary Service Center in Korea. This study was performed to evaluate sensitivity and group specificity of some antimicrobial drugs in FPT and to compare FPT with Charm II test. The minimal detectable levels of targeted antimicrobial drugs tested with standard solutions were 0.025-1.0 ppm for 7 beta-lactams, 0.5-1.0 ppm for 4 aminoglycosides, 0.05-0.5 ppm for 5 macrolides, 0.05-0.25 ppm for 3 tetracyclines and 0.25-1.0 ppm for 6 sulfonamides. In identification of the families, five families of antimicrobial drugs were identified. In this case, beta-lactams, aminoglycosides, macrolides, tetracyclines and sulfonamides could be detectable. In comparison of FPT and Charm II test, the results of FPT were not accord with those of Charm II test having the group specificity of seven families of antimicrobial drugs in meat samples except some families like tetracyclines.