取2 g带鱼可食用部分,加入20 mL乙酸乙酯,涡旋1 min,振荡30 min,离心5 min。取乙酸乙酯相,减压旋蒸至近干,加入10%(体积分数,下同)乙腈溶液2 mL溶解残渣。振摇后转移至10 mL容量瓶中,再用10%乙腈溶液2 mL重复洗涤一次,合并洗涤液,用10%乙腈溶液定容。离心5 min,上清液过0.22 μm滤膜,滤液供高效液相色谱-串联质谱法测定。以Waters Atlantis dC₁₈色谱柱为固定相,以不同体积比的乙腈和0.1%(体积分数)甲酸溶液的混合溶液为流动相进行梯度洗脱。分离后的表没食子儿茶素没食子酸酯、表没食子儿茶素、表儿茶素没食子酸酯、表儿茶素以电喷雾离子源负离子模式电离,多反应监测模式检测,基质匹配法定量。结果显示,4种茶多酚的质量浓度在10~200 μg·L^-1内与对应的峰面积呈线性关系,检出限为0.03 mg·kg^-1。对空白带鱼样品进行3个浓度水平的加标回收试验,回收率为81.2%~92.0%,测定值的相对标准偏差(n=6)小于7.0%。

An aliquot (2 g) of the edible part of hairtail was taken, and 20 mL of ethyl acetate was added. The mixture was oscillated for 1 min, shaken for 30 min, and centrifuged for 5 min. The ethyl acetate phase was taken, and spin evaporated to near dryness under reduced pressure, and 2 mL of 10% (volume fraction, the same below) acetonitrile solution was added to dissolve the residue. After shaking, the mixed solution obtained was placed into a 10 mL-volumetric flask, and 2 mL of 10% acetonitrile solution was used for repeated washing. The washing solutions were combined, and its volume was made up with 10% acetonitrile solution. After centrifugation for 5 min, the supernatant was passed through a 0.22 μm filter membrane, and the filtrate was determined by high performance liquid chromatography-tandem mass spectrometry. The chromatographic column of Waters Atlantis dC₁₈ was used as the stationary phase, and the mixed solution composed of acetonitrile and 0.1% (volume fraction) formic acid solution at different volume ratios was used as the mobile phase for gradient elution. The separated epigallocatechin gallate, epigallocatechin, epicatechin gallate and epicatechin were ionized by the electric spray ion source with negative ion mode, detected by the multiple reaction monitoring mode, and quantified by the matrix matching method. It was shown that linear relationships between the mass concentration of the 4 tea polyphenols and the corresponding peak area were kept in the same range of 10-200 μg·L^-1, with detection limit of 0.03 mg·kg^-1. The spiked recovery test was made on blank hairtail sample at three concentration levels, giving results of recovery in the range of 81.2%-92.0%, and RSDs (n=6) of the determined values were less than 7.0%.