nREfl TWELVE - NINTER 



0.01 0.1 

 ^1 1 1 — I 



100 - 



200 



LiJ 



330 - 



400 



500 \ 1 1 — I . I I M l 



0.01 



I 1 I 



NITRRTE (pg-a/L) 



J I I I I 1 -1-500 



Figure A. 3. 



121 



