Schedule 2755
Description: NAWQA, Ground Water, Nutrients
Analyzing Laboratory(s):
USGS - National Water Quality Laboratory, Denver, CO
Analyte CAS Number RL Unit
nitrogen, ammonia  7664-41-7 0.04 mg/L
nitrogen, nitrite  14797-65-0 0.008 mg/L
nitrogen, nitrite + nitrate  0.06 mg/L
Total nitrogen (NH3+NO2+NO3+Organic), filtered  17778-88-0 0.06 mg/L
phosphorus, phosphate, ortho  14265-44-2 0.006 mg/L
Container Requirements
Quantity     Bottle
1 125mL FCC
Description: 125 mL Brown polyethylene bottle,
Treatment and Preservation: Filter through 0.45-um filter, use filtered sample to rinse containers, chill and maintain at 4 deg C, ship immediately
1. OFR 93-125 
Fishman, M.J., ed., 1993, Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory--Determination of inorganic and organic constituents in water and fluvial sediments: U.S. Geological Survey Open-File Report 93-125, 217 p.
Method ID: I-2522-90 , I-2540-90 , I-2545-90 , I-2606-89
2. WRIR 03-4174 
Patton, C.J., Kryskalla. J.R., Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory ? Evaluation of Alkaline Persulfate Digestion as an Alternative to Kjeldahl Digestion for Determination of Total and Dissolved Nitrogen and Phosphorus in Water, Water-Resources Investigations Report 03-4174, 33p.
Method ID: I-2650-03
3. Memo - method approval announcement (July 2, 2003) 
Approval of a Water Quality Analytical Method for the Determination of Nitrogen and Phosphorus in Whole and Filtered Water by the National Water Quality Laboratory
Method ID: I-2650-03
4. Memo -- USEPA Approval for nationwide use of ATP method 
Telliard, W.A., USEPA, Director of Analytical Methods, Engineering and Anlysis Division