羊肉样品经0.3 mol·L-1氢氧化钠溶液提取,离心所得上清液过CEC18固相萃取柱净化。流出液用盐酸调整酸度pH至3.0±0.3后再过AccuBONDⅡODS-C18柱净化,依次用3%(体积分数)氨化甲醇1.00 mL和水0.30 mL洗脱,所得淋洗液供高效液相色谱分析。以Agilent ZORBAX SB-C18色谱柱为分离柱,以甲醇-水(40+60)混合液为流动相进行洗脱,用紫外检测器于波长283 nm处检测。3种硝基酚钠的质量浓度均在50~2 000 μg·L-1范围内与峰面积呈线性关系。在125,500,1 000 μg·L-1 3个添加水平下进行回收试验,硝基酚钠的回收率在74.5%~93.9%之间,相对标准偏差(n=5)小于6.5%。

Sample of mutton was extracted with 0.3 mol·L-1 NaOH solution, after centrifugation, the supernatant was taken and purified by passing through CEC18 solid phase extraction column. The eluate was adjusted to pH 3.0±0.3 with HCl and then further purified by passing through AccuBONDⅡODS-C18 column. The column was eluted with 1.00 mL of 3% (φ) ammoniated methanol and 0.30 mL of water successively. The eluate obtained was used for HPLC analysis. Agilent ZORBAX SB-C18 was used as stationary phase for separation, and a mixture of methanol and water (40+60) was used as mobile phase. The contents of sodium nitrophenolates were determined by UV-detection at the wavelength of 283 nm. Linear relationships between peak area and mass concentration of 3 sodium nitrophenolates were kept in the same range of 50-2 000 μg·L-1. Tests for recovery and precision were tested by addition of 125, 500, 1 000 μg·L-1 of standard solution, and analyzed by the proposed method, giving values of recovery in the range of 74.5%-93.9% and values of RSD′s (n=5) less than 6.5%.