[1] [1] U.S. EPA Office of Ground Water and Drinking Water/Technical Support Center. Methods for the Determination of Organic and Inorganic Compounds in Drinking Water, Volume 1-300.1, Rev 1.0 Determination of Inorganic Anions in Drinking Water by Ion Chromatography, (NSCEP PB 815-R-00-014), 1997.

[2] [2] American Public Health Association. Standard Methods for the Examination of Water and Wastewater, 20th Edition-4500-NO3-H Automated Hydrazine, Washington, DC, 1998.

[3] [3] U.S. EPA National Exposure Research Laboratory. Methods for Chemical Analysis of Waters and Wastes-Nitrite 353.1, Nitrogen, Nitrate-Nitrite (Colorimetric, Automated Hydrazine Reduction, EPA-600/4-79/020(NTIS PB 84-128677), Issued 1971; Reissued with Revision 1978.

[4] [4] U.S. EPA National Exposure Research Laboratory. Methods for Chemical Analysis of Waters and Wastes -Nitrate 353.2, Rev 2.0 Determination of Nitrate-Nitrite Nitrogen by Automated Colorimetry, EPA-600/R93/100(NTIS PB 84-120821), 1993.

[5] [5] U.S. EPA National Exposure Research Laboratory. Methods for Chemical Analysis of Waters and Wastes -Nitrate 300.0, Rev 2.1 Determination of Inorganic Anions by Ion Chromatography, EPA-600/R93/100(NTIS PB 94-120810), 1993.