顺序注射荧光法测定生鲜牛奶中碱性磷酸酶

以4-甲基伞形酮磷酸酯(4-MUP)为碱性磷酸酶(ALP)的底物,通过顺序注射荧光法检测乳制品中ALP的活性,进而对巴氏杀菌水平进行评价.结果表明,在最佳条件下相对荧光强度与ALP活性在50～1 000 mU/L范围内呈线性关系,其回归方程为△F=143.4CALP+6.859(r2=0.998 8),相对标准偏差为2.3％(200 mU/L,n=11),检出限(n=11)为14.0 mU/L,分析频率为15 h-1.方法自动化程度高、试剂试样用量少,将其应用于鲜奶和巴氏灭菌奶中ALP活性测定,准确性较好,加标回收率在90.01％～99.95％.

Determination of alkaline phosphatase in milk products using sequential injection-fluorometry method

In the present work, a sequential injection-fluorometry system was employed for the deter- mination of ALP, and applied to evaluate pasteurization level of milk products. The method was based on the catalytic reaction between alkaline phosphatase （ALP） and 4-methylumbelliferone phos- phate （4-MUP）. Under the optimal conditions, the calibration curve showed an excellent linearity in the concentration range of 50-1 000 mU/L, the linear regression equation is △F = 143. 4 CALV ＋ 6. 859（r^2= 0. 9988）, and the relative standard deviation was 2.3% （200 mU/L, n = 11）, the limit of detection was 14.0 mU/L. The procedure was simple and fast, and a sampling frequency of 15 h-1 was obtained. This method has been used for the analysis of ALP in milk samples with satisfactory results.