环丙沙星在鸡蛋中的残留消除规律

Elimination rule on residues of ciprofloxacin in eggs of Laying hens

用高效液相色谱法检测鸡蛋中环丙沙星的残留量。鸡蛋经乙腈溶液提取,提取液真空干燥后用流动相溶解。以0.015mol·L-1四丁基溴化铵/乙腈(体积比为94/6)作流动相,用SymmetryC18柱(5μm,3.9mm×150mm),在激发波长280nm、发射波长455nm处用荧光检测器检测。结果表明:环丙沙星以0.05、0.50和1.00mg·kg-1分别添加到空白鸡蛋样品中,测得的鸡蛋样品中环丙沙星回收率分别为(82.2±6.8)%、(84.5±5.9)%和8(7.9±4.7)%,相对标准差均低于8.3%。用该法测定的鸡蛋中环丙沙星最低检测限为0.01mg·kg-1。各试验组产蛋鸡给药剂量分别按体重10.0、20.0mg·kg-1内服环丙沙星水溶液,每天给药1次,连续5d,鸡蛋中环丙沙星残留量逐渐增大,服药5d后停药,鸡蛋中环丙沙星残留消除缓慢,休药8-9d时鸡蛋中环丙沙星残留量低于0.03mg·kg-1,休药9-10d时鸡蛋中环丙沙星残留量均低于最低检测限;且随着环丙沙星给药剂量的增大,环丙沙星在鸡蛋中的残留量也相应增大。

A high performance liquid chromatographic method was reported for the quantitative determination of residues of ciprofloxacin in eggs of Laying hens. Ciprofloxacin was extracted from eggs with acetonitrile solution. The extract solution was dried in vacuum condition (45℃) and residues were dissolved in mobile phase. Ciprofloxacin was separated on a Symmetry C18 Column (5 μm,3. 9 mm×150 mm) by 0. 015 mol·L-1 tetrabutyl ammonium bromide/ace-tonitrile (94/6,v/v) and detected at λEX 280 nm, λEM 455 nm by fluorescence detector. Recoveries of ciprofloxacin added to blank eggs at levels of 0. 05, 0. 50, 1. 00 mg·kg-1 were (82. 2±6. 8)%, (84. 5±5. 9)% and (87. 9±4. 7), respectively. This method permitted the minimum detection limit of ciprofloxacin residues in eggs at levels of 0. 01 mg·kg-1. After the Laying hens orally administered successively ciprofloxacin hydrochloride solution of 10. 0 and 20. 0 mg·kg-1 of body weight one time every day for 5 days, respectively, residues of ciprofloxacin in eggs were eliminated slowly. Residues of ciprofloxacin in eggs were lower than 0. 03 mg·kg-1 at 8th-9th withdrawal day. Residues of ciprofloxacin in eggs were all lower than the minimum detection limit (0. 01 mg·kg-1) at 9th-10th withdrawal day. With the increase of ciprofloxacin orally adminietered doses, residues of ciprofloxacin in eggs were increased, accordingly.