Biblioteca Virtual en Salud

Objective To prepare the candidate reference materials for frozen mixed serum potassium, in order to calibrate and evaluate the conventional methods to achieve mutual recognition of the results.Methods Fresh sera without hemolysis,lipemia and choloplania were collected.Serum pools were packed in the freezing tube in the 1 000 (1 ml/per).Use the Single Factor Analysis of Variance(ANOVA) to evaluate the homogeneity.The short-and long-term stability [(2 -8℃,room temperature,37 ℃) and long-term (-80 ℃ ) ] were investigatedby linear regression analysis.The value was assigned by transfer from NIST SRM-956c using reference method by ICP-MS and uncertain was calculated.We observed the commutability of 25 fresh patient serum samples and 3 levels candidate RMs between reference method and three analyzed systems.The candidate RMs( refernce materials) were then distributed to 33 laboratories in Beijing to apply in routine assay by using different detection systems.Results By statistical analysis of the SPSS 17 statistical software, the F value of homogeneity test of each level candidate RMs was 0.247, 0.117, 0.162.All of them were less than F0.05 (9,20) =2.39;Stability can be last at least 12 months,30 days, 12 days and 4 days at -80 ℃, 2-8℃, room temperature and 37℃respectively.The definited values of three levels candidate RMs for potassium were (2.349 ±0.028) mol/L,(3.845 ±0.024) mol/Land (5.831 ±0.042)mol/L;Coordinate dots of 3 levels candidate RMs are all within 95% confidence interval range of 25 serums regression line.They have the same speciality as serum.In correctness verification survey of 33 clinical laboratory of conventional methods,97%bias in results The biases of 97%RMs were within the range of ±2.5%( ±1/2 CLIA′88Tea).Conclusion The homogeneity, stability and commutability of 3 levels candidate RMs all meet the requirement and the target values are assigned accurately.