Results for several natural water s

Results for several natural water samples are reported in
Table 1. The results agree well with that of the indolphenol blue
method, y¼0.9809þ0.462, r¼0.9987. We did observe some carryover;
for best results repeat runs were made and data from the
first run for each sample was discarded. In replicate measurements
(n¼3), the typical variance was o5%.