HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Klingaman, E. D. Articles by Nelson, D. W. Search for Related Content PubMed Articles by Klingaman, E. D. Articles by Nelson, D. W. Agricola Articles by Klingaman, E. D. Articles by Nelson, D. W.

Evaluation of Methods for Preserving the Levels of Soluble Inorganic Phosphorus and Nitrogen in Unfiltered Water Samples¹

ABSTRACT

Several methods for preserving the levels of soluble inorganic phosphorus (SIP), ammonium, and nitrate in surface runoff, tile drainage water, and river water were evaluated. The best overall technique for preservation of water samples for P and N analysis appeared to be storage at subzero temperatures. The SIP concentration in samples was also stabilized by addition of HgCl₂ (40 mg/liter) and storage at 4C; however, the ammonium and nitrate levels in samples were not preserved for long periods of time (12 weeks) by this technique. The soluble inorganic N levels in water samples were preserved by addition of phenylmercuric acetate (20 mg/liter) and storage at 4C, but use of this procedure increased the SIP concentration in some samples during storage. Storage of samples at 4C or 23C without addition of a chemical preservative resulted in large changes in soluble inorganic P and N contents.

Key Words: orthophosphate • ammonium • nitrate • frozen storage • surface runoff • tile drainage water

¹ A contribution of the Agric. Exp. Sta., Purdue University, Lafayette, IN 47907. Purdue Journal Ser. Paper No. 5767.

² Research Assistant and Associate Professor of Agronomy, respectively.

Received for publication January 17, 1975.