Abstract:

Objective To establish a national standard reference material of aldosterone in frozen human serum for the transfer of measurement values and the evaluation of accuracy in aldosterone determination. Methods Clinical serum samples with clear appearance，no obvious jaundice，hemolysis or lipemia，and negative results for 4 infectious disease determinations were collected. After multi-level filtration and sterilization，the samples were classified into high- and low- level candidate reference materials and stored at -70 ℃ or below. The homogeneity，stability and intercommunity of the candidate reference materials were evaluated. Totally，5 laboratories were selected to jointly assign values using the reference method（isotope dilution liquid chromatography-tandem mass spectrometry）. Results The results of homogeneity test showed that the F values of the high- and low- level candidate reference materials were 1.355 3 and 1.473 3，respectively，both <F_0.05（1.511 7）. The results of stability test showed that the candidate reference materials were stable for 5 h at room temperature，20 d at 2-8 ℃，and at least 30 d at -20 ℃. The assigned values of the high- and low- level candidate reference materials were（0.239±0.018）nmol·L^-1（k=2） and（0.845±0.052）nmol·L^-1（k=2），or（86.22±6.31）pg·mL^-1（k=2） and（304.74±18.80）pg·mL^-1（k=2），respectively. The intercommunity of the 2 levels of candidate reference materials was good in 5 mainstream routine determination systems. Conclusions The established aldosterone candidate reference materials are homogeneous and stable and have good intercommunity，with accurate and reliable assigned values，and can be used as national standard reference materials. The establishment of this national standard reference material is of significance for promoting the standardization of aldosterone determination results.

Key words: Aldosterone, Frozen human serum, National standard reference material