用磷钼酸喹啉重量法测定复混肥料中有效P_2O_5含量。为了合理表征测量值的分散性,确定测试结果的有效性,对测定过程进行不确定度评定。测定结果的不确定度来源主要有天平称量、样品分取、重复性实验等。得到复混肥料样品中有效P_2O_5测定结果的合成标准不确定度u_c(w)=0.021%,扩展不确定u_c=0.042%(包含因子k=2)。 Determination of Available P_2O_5 in Compound Fertilizers by Quinoline Phosphomolybdate Gravimetric Method. In order to reasonably characterize the dispersion of the measured values, determine the validity of the test results, and evaluate the uncertainty of the measurement process. Uncertainties in the determination of the main sources of balance weighing, sample collection, repetitive experiments. The synthetic standard uncertainty u_c (w) = 0.021% and u_c = 0.042% (including the factor k = 2) of the effective P_2O_5 determination results were obtained.