高效液相色谱法检测牛奶及其制品中的溶菌酶

Determination of lysozyme in milk and its dairy products by high performance liquid chromatography

中文关键词:  溶菌酶  高效液相色谱法  荧光检测  牛奶及奶酪制品

英文关键词:lysozyme  high performance liquid chromatography  fluorescence detection  milk and cheese

中文摘要:

      目的 建立一种测定牛奶及奶酪制品中低含量溶菌酶的高效液相色谱-荧光检测新方法。方法 样品经pH 6.0的氯化钠溶液活化, 再在低pH值条件下除蛋白后, 采用反相色谱柱(PLRP-S 250 mm×4.6 mm, 300 ?, 5 μm)用A水(0.1%的三氟乙酸(trifluoroacetic acid, TFA)), B乙腈(0.1%TFA)体系作为流动相进行梯度洗脱, 使用荧光检测器在激发波长(λex)276 nm, 发射波长(λem)345 nm处检测。结果 最优实验条件下, 溶菌酶在2.0~30.0 mg/L浓度范围内线性良好, 加标实验结果显示回收率和相对标准偏差(relative standard deviation, RSD)分别在92.3%~104.3%和0.81%~3.26%之间, 对牛奶和奶酪制品的检出限分别为20和40 mg/kg。结论 该方法操作简便, 结果准确、可靠, 可用于乳制品中溶菌酶含量测定。

英文摘要:

      Objective To establish a new method for the determination of low-level lysozyme in milk and cheese products by high performance liquid chromatography-fluorescence detection. Methods The sample was activated by a pH 6.0 sodium chloride solution, and after removing the protein at a low pH, a reversed phase column (PLRP-S 250 mm×4.6 mm, 300 ?, 5 μm) was used with A water (0.1% of trifluoroacetic acid (TFA)) and B acetonitrile (0.1% TFA) system as a mobile phase for gradient elution, using a fluorescence detector at the excitation wavelength (λex) of 276 nm and emission wavelength (λem) of 345 nm. Results Under the optimal experimental conditions, lysozyme showed good linearity in the concentration range of 2.0-30.0 mg/L. The results of spiked experiments showed that the recovery rates and relative standard deviations (RSDs) were 92.3%-104.3% and 0.81%-3.26%, respectively. The limits of detection for milk and cheese products were 20 and 40 mg/kg, respectively. Conclusion This method is simple and convenient, which can be used for the determination of lysozyme content in dairy products.