Abstract:

Objective To develop and evaluate quality control materials of glycocholic acid（GCA），and to investigate the performance and capability. Methods Remaining sera from Shanghai East Hospital（hepatitis B surface antigen，hepatitis C virus antibody，human immunodeficiency virus antibody，Treponema pallidum antibody all negative） were collected，and high-level and low-level GCA quality control materials were prepared. The homogeneity，stability and commutability of quality control materials were evaluated. They were distributed to 14 clinical laboratories in Shanghai for applicability investigation，in order to understand the difference of GCA determination results between mass spectrometry and immunological methods （latex enhanced immunochromatography，homogeneous enzyme immunoassay）. Results The homogeneity of GCA quality control materials was good （F values were 1.151 and 0.889，respectively）. The storage at 4 ℃ for 7 d and at-20 ℃ and -80 ℃ for 6 months showed good stability [linear equation slope /b1/<t_{（0.95，n-2）}·S（b1），the difference between slope and 0 was not statistically significant]. The results of quality control materials were all within the 95% confidence interval of the fitted regression line established by the fresh serum samples，which had good commutability. The preliminary investigation results showed that the GCA levels of high level quality control material by mass spectrometry，latex enhanced immunochromatography and homogeneous enzyme immunoassay were 13.65，37.54 and 44.56 μg·mL^-1，respectively，and those of low level quality control material were 0.49，2.76 and 2.39 μg·mL^-1，respectively. Conclusions The prepared GCA quality control materials have good homogeneity，stability and commutability. The results of GCA determination by mass spectrometry and immunoassay are different. The development of reference materials and the establishment of traceability system are the efforts to promote the comparability of clinical GCA determination results.

Key words: Glycocholic acid, Quality control material, Homogeneity, Stability, Commutability