With 3, 3’5, 5’-tetramethylbenzidine（TMB） as the detection substrate, a reliable and highly selective method was established and optimized for the determination of Lactoperoxidase（LP） activity in raw milk. The m...With 3, 3’5, 5’-tetramethylbenzidine（TMB） as the detection substrate, a reliable and highly selective method was established and optimized for the determination of Lactoperoxidase（LP） activity in raw milk. The method was based on the enzymatic reaction principle, where hydrogen peroxide oxidated TMB in the presence of LP. The optimized conditions of this assay system were obtained, consisting of 20 mmol · L-1 TMB solution, 0.6 mmol · L-1 hydrogen peroxide and 0.1 mol · L-1 Citric Acid（CA）/0.2 mol · L-1 disodium hydrogen phosphate（Na P） buffer（pH 4.8）. TMB detection method was applied to the analysis of LP in milk samples with a practical working concentration range from 2 to 14 mg · L-1. The intra-and inter-batch variation coefficients were all below 5%, indicating a good repeatability. Confirmation test between TMB method and 2, 2-azinobi（3-ethylbenzothiazoline-6-sulphonate） diammonium salt（ABTS） method was carried out, and the results of TMB assay were in accordance with that of ABTS method.展开更多
为了研究锂渣粒度的分布规律,采用LS-POP（Ⅵ）型激光粒度仪分析锂渣溶液质量浓度、超声分散时间和分散频率、分散介质对锂渣粒度的影响,并讨论SBT-127型数显勃氏透气比表面积仪与激光粒度仪测定比表面积的相关性。结果表明：与煤油和...为了研究锂渣粒度的分布规律,采用LS-POP（Ⅵ）型激光粒度仪分析锂渣溶液质量浓度、超声分散时间和分散频率、分散介质对锂渣粒度的影响,并讨论SBT-127型数显勃氏透气比表面积仪与激光粒度仪测定比表面积的相关性。结果表明：与煤油和无水乙醇相比,水对锂渣的分散效果较好,适宜用作锂渣的分散介质;采用水为分散介质时,锂渣粒度的检测条件分别是锂渣质量浓度为3~4 g/L,超声分散时间不少于4 min,超声分散频率不小于40 k Hz;以此条件重复5次实验发现,锂渣的粒度分布曲线重合性较好,中位粒径的变异系数小于3%;激光衍射法测定的比表面积比数显勃氏透气法测定的小,但是两者具有较好的相关性。展开更多
基金Supported by Project for Research and Development of Harbin Aapplication Technology(2016RAQXJ046)the National "Twelfth Five-year" Plan for Science and Technology Support Program of China(2013BAD18B06)
文摘With 3, 3’5, 5’-tetramethylbenzidine（TMB） as the detection substrate, a reliable and highly selective method was established and optimized for the determination of Lactoperoxidase（LP） activity in raw milk. The method was based on the enzymatic reaction principle, where hydrogen peroxide oxidated TMB in the presence of LP. The optimized conditions of this assay system were obtained, consisting of 20 mmol · L-1 TMB solution, 0.6 mmol · L-1 hydrogen peroxide and 0.1 mol · L-1 Citric Acid（CA）/0.2 mol · L-1 disodium hydrogen phosphate（Na P） buffer（pH 4.8）. TMB detection method was applied to the analysis of LP in milk samples with a practical working concentration range from 2 to 14 mg · L-1. The intra-and inter-batch variation coefficients were all below 5%, indicating a good repeatability. Confirmation test between TMB method and 2, 2-azinobi（3-ethylbenzothiazoline-6-sulphonate） diammonium salt（ABTS） method was carried out, and the results of TMB assay were in accordance with that of ABTS method.
文摘为了研究锂渣粒度的分布规律,采用LS-POP（Ⅵ）型激光粒度仪分析锂渣溶液质量浓度、超声分散时间和分散频率、分散介质对锂渣粒度的影响,并讨论SBT-127型数显勃氏透气比表面积仪与激光粒度仪测定比表面积的相关性。结果表明：与煤油和无水乙醇相比,水对锂渣的分散效果较好,适宜用作锂渣的分散介质;采用水为分散介质时,锂渣粒度的检测条件分别是锂渣质量浓度为3~4 g/L,超声分散时间不少于4 min,超声分散频率不小于40 k Hz;以此条件重复5次实验发现,锂渣的粒度分布曲线重合性较好,中位粒径的变异系数小于3%;激光衍射法测定的比表面积比数显勃氏透气法测定的小,但是两者具有较好的相关性。
