羊乳中替米考星残留的检测方法研究

建立了羊乳中替米考星残留的反相高效液相色谱检测方法。羊乳按1:1(V/V)用乙腈提取，上清液以5ml/min 流速过C18 SPE 柱，采用乙腈- 水(20:80，V/V)洗涤、乙腈- 水(90:10，V/V)洗脱，并以0.1mol/L 乙酸铵- 乙腈-甲酸(60:30:10，V/V)为流动相，采用高效液相色谱仪在280nm 处使用紫外检测器检测。本法定量限(LOQ)为0.02μg/ml，平均回收率范围在90.3%～98.1% 之间，线性范围为0.01～25μg/ml，变异系数范围在4.1%～8.9% 之间。本法可满足残留分析的要求，为羊乳中替米考星的残留分析提供了可靠的检测方法。

HPLC Determination of Tilmicosin Residue in Goat Milk

A reverse phase HPLC method was developed for the determination of tilmicosin residue in goat milk. Samples were extracted using methanol, and cleaned-up using SPE on a C18 cartridge with a mixture of acetonitrile and water (90:10, V/V) as the eluent [the washing with a mixture of acetonitrile and water (20:80, V/V) was carried out prior to elution]. The analysis was performed on a Symmetry column with a mobile phase composed of 0.1 mol/L ammonium acetate (adjusted to pH 5.0 with formic acid), acetonitrile and methanol (60:30:10, V/V) using a UV detector set at 280nm. The limit of quantification was 0.020 μg/ml and the linear range was 0.01－25 μg/ml, and the spike recoveries at three levels of 0.02－5 μg/ml were in the range of 90.3%－98.1% with a coefficients of variation ranging 4.1%－8.9%. The method can meet the requirement for tilmicosin residue analysis.