Pb2+-NaOH介质中蛋白质水解物的极谱吸附波及其应用Pb2+-NaOH介质中蛋白质水解物的极谱吸附波及其应用

目的建立一种快速、简便、灵敏的蛋白质含量测定的新方法。方法含有巯基或二硫基的蛋白质与0.5 mol·L^-1氢氧化钠、1.5×10^-4 mol·L^-1 Pb²⁺和0.02%四丁基碘化铵的混合溶液在沸水浴中反应5 min，采用单扫描极谱法，测定-0.66 V(vs SCE)处一价导数波高。结果牛血清白蛋白（BSA）、人血清白蛋白（HSA）的浓度在7.5×10^-10～3.0×10^-7 mol·L^-1与其波高呈线性关系，BSA和HSA检测限均为3.0×10^-10 mol·L^-1；溶菌酶(Lyso)的浓度在1.4×10^-8～1.3×10^-6 mol·L^-1与其波高呈线性关系，Lyso的检测限为7.0×10^-9 mol·L^-1。结论该方法取样量少、体系简单、灵敏度高，可用于人血清样品中蛋白质含量的测定。

Polarograhic adsorptive wave of protein hydrolysate in Pb2+ and sodium hydroxide solution and its application

AIM: To propose a new simple and sensitive voltammetric method for determination of proteins. METHODS: Protein with sulfhydryl or disulfide bond in 0.5 mol x L(-1) NaOH, 1.5 x 10(-4) mol x L(-1) Pb2+ and 0.02% tetrabutylammonium iodide was heated in boiling water for 5 minutes. The reactive product gave a well defined reductive adsorption wave at -0.66 V (vs SCE) by means of single sweep polarography, and the height of derivative wave was proportional to the concentration of proteins. RESULTS: The peak height was linearly proportional to bovine serum albumin (BSA) or human serum albumin (HSA) concentration in range of 7.5 x 10(-10) -3.0 x 10(-7) mol x L(-1) (r(BSA) = 0.9995, and r(HSA) = 0.9990). The detection limit of BSA or HSA was 3.0 x 10(-10) mol x L(-1). For lysozyme (Lyso), the concentration range was from 1.4 x 10(-8) to 1.3 x 10(-6) mol x L(-10 (r(Lyso) = 0.9997) and the detection limit was 7.0 x 10(-9) mol x L(-1). CONCLUSION: The method is simple, rapid, sensitive and applicable to the assay of diluted human serum albumin samples.