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

References

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