Bandi Z L, Fuller J B, Bee D E, James G P
Clin Chem. 1981 Mar;27(3):480-5.
We followed the "abbreviated precision protocol" of the National Committee for Clinical Laboratory Standards for the evaluation of precision, accuracy, and carryover in analysis for urea nitrogen with the multilayer film analysis system ("Ektachem"). We analyzed 456 clinical samples with this instrument, by the manual urease/glucose dehydrogenase method, and with the Beckman System I GLU/BUN Analyzer. Precision and accuracy were estimated for 50, 220, 270, and 500 mg/L urea nitrogen concentrations in 100, 30, or 20 microL of serum. Potential interference of 15 compounds was evaluated. Random error (defined as 1.965 X SD) was 7, 10, 12, and 18 mg/L. Systematic error was 3, 4, 5, and 15 mg/L. Total analytical error was 11, 14, 17, and 34 mg/L for analysis of 100 microL of serum at the above-stated urea nitrogen concentrations. The greatest interference (6 mg/L) was caused by ethanol (300 mg/L) and by hemoglobin (500 mg/L) in the urea nitrogen (at 260 mg/L) determination. Urea nitrogen concentration, as determined with the Ektachem was linearly related to the expected concentration, at least up to 1187 mg/L. Carryover was not statistically significant.
我们遵循了美国国家临床实验室标准委员会的“简化精密度方案”，以评估使用多层膜分析系统（“Ektachem”）进行尿素氮分析时的精密度、准确度和携带污染情况。我们使用该仪器、手工脲酶/葡萄糖脱氢酶法以及贝克曼系统I GLU/BUN分析仪对456份临床样本进行了分析。对100、30或20微升血清中尿素氮浓度为50、220、270和500毫克/升的情况评估了精密度和准确度。评估了15种化合物的潜在干扰。随机误差（定义为1.965×标准差）分别为7、10、12和18毫克/升。系统误差分别为3、4、5和15毫克/升。对于上述尿素氮浓度下100微升血清的分析，总分析误差分别为11、14、17和34毫克/升。在尿素氮（260毫克/升）测定中，乙醇（300毫克/升）和血红蛋白（500毫克/升）造成的干扰最大（6毫克/升）。用Ektachem测定的尿素氮浓度与预期浓度呈线性相关，至少在1187毫克/升以内。携带污染无统计学意义。
