Nitrite (NO2) and Nitrate (NO3) 
 PI: Zackary Johnson (Duke University) 
 Version History: 
   Dataset updated: 10 July 2014 (current version) 
   Original data:   25 Oct 2012 
 Note: 0 = mean of replicated samples was below detection limit. Detection limits: 
         POWOW1 & POWOW2: 0.05 uM for NO2; 0.1 uM for NO3 
         POWOW3: 0.05 uM for NO2; 0.05 uM for NO3