Matched context for impurity and hc

The page lists matched contexts for impurity and hc.

Share - impurity	Share - hc	Phrase
3.66%	5.37%	oxidize {impurity or hc} [perform operation]
4.42%	3.07%	{impurity or hc} concentration
16.54%	0.74%	remove {impurity or hc} [perform operation]
5.76%	1.34%	contain {impurity or hc} [perform operation]
0.82%	0.18%	cause {impurity or hc} [perform operation]
0.76%	0.08%	prevent {impurity or hc} [perform operation]