Matched context for impurity and co

The page lists matched contexts for impurity and co.

Share - impurity	Share - co	Phrase
4.42%	6.16%	{impurity or co} concentration
3.66%	5.98%	oxidize {impurity or co} [perform operation]
16.54%	1.22%	remove {impurity or co} [perform operation]
5.76%	1.96%	contain {impurity or co} [perform operation]
0.82%	0.12%	cause {impurity or co} [perform operation]