AZUR Environmental organized two sequential round robin studies in September and December, 1998 soliciting participants from the commercial and government sectors. ARI participated in both studies. Test samples provided by AZUR in each study included three simulated effluent samples and three unknown chemical samples. Each sample was tested three times to generate a EC50. The reproducibility as exhibited by the coefficient of variability (CV) for EC50s from each set of three tests per sample are reported below. The average CV for each participating laboratory for all samples tested and the grand mean CV for all samples within a study for all labs is also provided. These data demonstrated that AquaTox Research personnel generated the lowest amount of variability among samples in the first study and the second lowest amount of variability in the second study.
%CV Results from September, 1998 Round Robin Study
 
REFERENCE SAMPLES EFFLUENT SAMPLES
 
LAB
A
B
C
1
2
3
AVERAGE % CV
AQUATOX
1.44
30.2
14.1
7.94
16.2
11.7
13.6
M
2.32
42.0
11.1
37.6
71.0
6.74
28.5
K
14.3
19.2
22.3
34.1
13.8
15.1
18.9
X
13.7
29.1
29.4
13.4
7.33
82.8
29.3
L
8.54
36.4
16.2
40.3
31.6
9.62
23.8
U
6.64
42.8
10.5
23.3
29.6
85.4
33.0
Y
63.9
121
13.0
33.4
22.6
-
50.7
P
18.2
49.9
20.8
34.7
18.1
17.9
26.6
Z
11.8
37.2
12.1
24.8
18.2
47.9
25.3
J
-
-
-
82.4
79.8
14.3
58.8
T
10.6
35.0
10.7
38.3
56.5
81.4
38.7
A
7.74
20.7
8.34
22.1
24.3
14.6
16.3
AVERAGE %CV
14.5
42.1
15.3
32.7
32.4
35.2
-
POOLED %CV FOR ALL LABS AND SAMPLES
28.7

%CV Results from December, 1998 Round Robin Study
 
REFERENCE SAMPLES
EFFLUENT SAMPLES
 
LAB
AA
BB
CC
E2
E3
E4
AVERAGE % CV
AQUATOX
10.9
30.7
19.2
7.1
10.5
 
9.7
14.7
MM
5.62
33.7
11.2
16.5
29.1
12.9
18.2
KK
21.0
34.1
17.5
9.7
2.8
11.4
16.1
XX
1.7
32.0
13.2
19.9
12.0
47.4
21.0
LL
3.81
13.9
21.0
6.6
25.5
15.8
14.4
PP
25.5
21.3
16.5
19.3
43.2
9.2
22.5
ZZ
5.2
28.8
14.8
23.0
18.6
-
18.1
TT
2.8
19.1
25.0
12.9
21.0
14.5
15.9
AA
10.8
18.8
18.6
14.9
15.9
12.3
15.2
AVERAGE %CV
9.7
25.8
17.4
14.4
19.8
17.1
-
POOLED %CV FOR ALL LABS AND SAMPLES
17.4