市售萊克多巴胺快篩試劑檢驗效能之評估   全文下載

Evaluation of Commercial Ractopamine Rapid Test Kits

萊克多巴胺（Ractopamine）屬乙型受體素（β-agonist）之一種，添加於動物飼料中，具增加禽畜動物之瘦肉比例、減少脂肪堆積以及增加動物飼料利用率等特性，故國際上有國家核准其可作為動物之飼料添加物，如美國、加拿大、澳洲等。目前國內食品中萊克多巴胺之檢驗係以衛生福利部公告之「食品中動物用藥殘留量檢驗方法－乙型受體素類多重殘留分析」進行檢測，該方法係將檢體經萃取、酵素水解、固相萃取匣淨化後，檢液以液相層析串聯質譜儀（Liquid chromatograph-tandem mass spectrometer, LC-MS/MS）分析，並利用內部標準品校正後之基質匹配檢量線進行定量。另外，目前亦有市售萊克多巴胺快篩試劑可利用畜肉檢體之肉汁檢測是否含有萊克多巴胺。本次研究目的係檢視萊克多巴胺快篩試劑之檢測效能，將84件畜肉檢體分別以兩款萊克多巴胺快篩試劑（A款及B款）及公告檢驗方法進行測試，分析快篩試劑之靈敏度、專一性、偽陰性率及偽陽性率，並評估快篩試劑與公告檢驗方法檢測結果之一致性。結果顯示，A款試劑之靈敏度、專一性、偽陰性率及偽陽性率分別為71、100、29及0%；B款試劑分別為76、74、24及26%；此外，以Cohen’s kappa（κ）係數評估兩款快篩試劑與公告檢驗方法檢測結果之一致性程度，結果顯示，A款試劑與公告檢驗方法檢測結果之一致性程度較B款試劑高。兩款快篩試劑之偽陰性率均有20%以上，惟偽陰性檢體所含萊克多巴胺介於0.001 - 0.004 mg/kg之間，皆未超過殘留容許量。倘此兩款快篩試劑應用於進口肉品，尚符合篩檢需求，惟快篩試劑產品係提供業者對特定風險物質進行自主管理時參考使用，若檢驗結果有疑義，仍應以公告檢驗方法之檢驗結果為準。

Ractopamine is a type of β-agonists, commonly used as an animal feed additive to improve leanness, reduce fatty buildup, and increase food conversion efficiency. This animal feed additive is approved in several countries, including the United States, Canada and Australia. In Taiwan, testing for ractopamine in food is performed by the “Method of Test for Veterinary Drug Residues in Foods–Test of Multiresidue Analysis of β-Agonists” published by the Ministry of Health and Welfare. In this method, β-agonists including ractopamine in the samples was extracted, enzymatically hydrolyzed, purified by solid phase extraction, analyzed over a liquid chromatograph–tandem mass spectrometer (LC-MS/MS), and finally quantified using matrix-matched curves calibrated with internal standards. Commercial rapid test kits are available to test whether the meat juice of livestock products contains ractopamine as well. In this study, 84 animal muscle samples were tested for ractopamine using two commercial rapid test kits, namely brand A and brand B, and the results were compared with the official method to evaluate the sensitivity, specificity, false negative and false positive rates. The sensitivity, specificity, false negative rate and false positive rate of the brand A kit were 71, 100, 29 and 0%, respectively, and those of brand B kit were 76, 74, 24 and 26%, respectively. Additionally, Cohen’s kappa was subsequently employed to evaluate the agreement of kit results with the official method. The brand A kit exhibited a higher level of agreement with the official method than the brand B kit did. Both brands yielded false negative rates of more than 20% while the ractopamine contents were in the range of 0.001 - 0.004 mg/kg, which were lower than the maximum residue limit. The results suggested that both brands of the test kits are adequate for imported meat products. However, users should bear in mind that commercial rapid test kits are designed for business operators to independently test the content of specific substances for potential hazards. As such, the results of test kits are for reference only. When in doubt, users should adhere to the official results.