血清钙测量参考方法的复现及方法学评价

Measurement of serum calcium by flame atomic absorption spectrometry： validation of a candidate reference method

目的用火焰原子吸收光度法复现血清钙的准确测定方法并加以考察，评价其是否可以作为候选参考方法应用于临床实验室。方法在盐酸和氯化镧存在条件下，将血清准确稀释50倍，使用处于最佳工作状态下的AA6800原子吸收分光光度计，在波长422．67nm处测定。结果在2个月内对2个浓度水平血清各测定6批，每批重复测定3次，批内变异系数（CV）为0．31％-0．38％；批间CV为0．16％-0．30％；总CV为0．35％～0．49％。在严格操作条件下，血清总钙测定准确度为±1％，回收率为98．9％～101．1％。实验证实，该测定方法未发现明显系统误差。基质中已知的其他成分对血清钙的测定结果无干扰。结论火焰原子吸收光度法测定血清钙精密度高、准确度好，建议其作为测定血清总钙的候选参考方法。

Objective To investigate the measurement of serum calcium by flame atomic absorption spectrometry （FAAS） and to validate the method for use as a candidate reference method. Methods Serum was diluted by 50 fold with 50 mmol/L hydrochloric acid containing 10 mmol/L LaCl3 and analyzed for calcium on an AA 6800 atomic absorption spectrophotometer. Dilution solutions and FAAS conditions were optimized and the performance of the method was evaluated. Results The method showed within-run, between-run and total CVs of 0. 31% -0. 38% , 0. 16% -0. 30% and 0. 35% -0. 49%, respectively, and analytical recoveries ranging 98. 9% - 101.1%. No significant interferences were detected. Conclusions A FAAS method for the measurement of serum calcium has been established. The method is simple and accurate and may be used as a candidate reference method for serum calcium.