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 Sullivan, D. M. Articles by Havlin, J. L. Search for Related Content PubMed Articles by Sullivan, D. M. Articles by Havlin, J. L. Agricola Articles by Sullivan, D. M. Articles by Havlin, J. L.

Flow Injection Analysis of Urea Nitrogen in Soil Extracts

Dep. of Agronomy and Soils, Washington State Univ., Puyallup Research and Extension Center, Puyallup, WA 98371-4998

J. L. Havlin

Dep. of Agronomy, Kansas State Univ., Manhattan, KS 66506

* Corresponding author.

ABSTRACT

Flow injection analysis (FIA) is a relatively new technique with advantages over traditional automated analysis methods in precision and sample throughput. A new procedure has been developed to measure urea in soil extracts using automated FIA. This procedure utilizes the diacetyl monoxime thiosemicarbazide colorimetric method, with a modified acid reagent that increases the rate of color formation and improves the mixing of sample with reagent in narrow-diameter (0.8-mm) tubing. Sixty samples can be analyzed per hour, with a detection limit of 0.01 mg urea-N L^–1. Residence time between sample injection and maximum absorbance is 130 s.

Contribution no. 90-137-J from the Kansas Agric. Exp. Stn.

Received for publication October 9, 1989.