Inter‐ and intralaboratory variability inDaphnia magnaeffluent toxicity test results

摘要

AbstractA nine‐laboratory round‐robin study of theDaphnia magnastatic, acute, effluent toxicity test was conducted to examine inter‐ and intralaboratory variability in test results. A single effluent sample was split and sent to three government, three commercial and three industrial aquatic laboratories. Each laboratory followed a specifically designed test protocol and reported the number of daphnids immobilized in each of seven effluent test concentrations at 24 h and 48 h of exposure. The mean 48‐h EC50 value for all data was 5.3 effluent. The range was 3.5 to 9.1 effluent, so there is a factor of 2.6 between the highest and lowest EC50 values. The pooled within‐laboratory standard deviation and coefficient of variation were 0.91 and 16, respectively. Combined inter‐and intralaboratory estimates of standard deviation and coefficient of variation were 1.8 and 33, respectively. The results of this study show thatDaphnia magnaeffluent toxicity data can be reproduced both within and between laboratories when clearly defined test protocols a