畜水產品中歐索林酸及乃託文檢方法之探討及其殘留量之調查

ANALYTICAL METHODS OF OXOLINIC ACID AND NITROVIN AND RESIDUES IN LIVESTOCK AND FISHERY PRODUCTS

本研究以快速，簡便的高效液相層析法（High Performance Liquid Chromatography） 對畜水產品中的抗菌劑─歐索林酸（Oxolinic acid）及乃託文（Nitrovin）之檢驗法進行探討，並調查市售或外銷之蝦類，鰻魚，豬肉，牛肉等檢體中歐索林酸及乃託文之殘留量，以確保國人之健康及維護外銷信譽。歐索林酸之檢驗方法是將檢體以二氯甲烷萃取、濃縮後，以正己烷去脂肪，再經二氯甲烷抽取濃縮後之殘留物，以重氮甲烷（Diazomethane）甲基化一小時，利用高效液相層析儀分析。以此法所得之最低檢測限量為50ppb。而分別添加歐索林酸0.3、1及2μg等三種量於四種不同之檢體中，其回收率為88.2～96.9%。變異系數是1.4～6.3%。抽購市售90件檢體，檢測其歐索林酸之殘留量，輸出七件，檢出率為7.7%，殘留量範圍在65～72ppb之間。乃託文（Nitrovin）。檢體經丙酮的萃取、濃縮後，以正己烷去脂肪，再以氯仿分配分層萃取，氯仿層濃縮至乾，殘留物以85%乙腈溶解通過Alumina SEP PAK，再以高效液相層析儀分析，添加不同量乃託文（1、5μg）於檢體之回收率為80.1～92.3 %，變異係數是1.7～6.1%，最低檢出限量為20 ppb，抽購市售雞肉及豬肉20件，檢測其乃託文之殘留量，均未檢出。

A simple, rapid high performance liquid chromatography (HPLC) method was described for the determination of oxolinic acid and its residues in livestock and fishery products. Five g of sample was extracted from meats by dichloromethane, removed lipids by n-hexane, then methylated by d-azomethane. The filtrate was subjected to HPLC with UV detector at 254nm. Separation was achieved by using Methanol : H2O (60 : 40)on Licrospher 100RP-18 column and flow rate 0.6ml / min. Oxolinic acid was found to have a retention time of about 5.2 minutes. Recoveries (C.V%) of three different levels (0.3 , 1 and 2J1g) were 88.2 ~ 96.9% (1.4 ~ 6.3%). The detection limit was 50ppb. For determination of nitrovin and its residues in livestock and fishery products, a simple, rapid high performance liquid chromatography (HPLC) method was developed. Ten g of sample was extracted from meats by aceton, removed lipids by n-hexene, and partitioned with chloroform, cleaned up by Alumina B SEP PAK. The filtrate was subjected to HPLC with UV detector at 380nm, Separation was achieved by using Acetonitrile : Acetic acid : H20 (70 : 0.1 : 30) on μ Bondapak C8l column and flow rate 0.6ml / min. Nitovin was found to have a retention time of about 6.5 minutes. Recoveries (C.V%) of three different levels (1 , 5 and 10μg) were 80.1~92.3% (1.7~6.1%). The detection limit was 20ppb.