Table 2. NAC quantification via HPLC.

Nominal concentrationa (mg/mL)	Measured concentrationb (mg/mL)	Standard deviation (St. Dev.)	% of NAC c	% of maximal NAC absorption d
0.48	0.29	0.081	56.9 - 23.1	33.2
2.40	1.98	0.458	36.6 - 0	12.9
6.00	6.16	0.182	0	0

^a Initial concentration of NAC that was added to the Leonard jars;

^b Concentration of NAC that was measured by HPLC from the samples that were collected from the Leonard jars after one week;

^c Absorption values discounting the Standard Dev;

^d discounting the NAC amount that was environmentally degraded (measured by NAC solution in Leonard jars without plants).