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United States Department of Agriculture

Agricultural Research Service

Title: A Simple Roller-Miller Grinding Procedure for Plant and Soil Samples

Authors
item Arnold, Spencer
item Schepers, James

Submitted to: Communications in Soil Science and Plant Analysis
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 1, 2004
Publication Date: January 1, 2004
Citation: Arnold, S.L., Schepers, J.S. 2004. A simple roller-miller grinding procedure for plant and soil samples. Communications in Soil Science and Plant Analysis 35:537-545.

Interpretive Summary: Many instruments today are moving towards smaller and smaller sample sizes, which require finely ground samples that are well mixed. The grinding and mixing ability of a roller-milling device using square bottles rather than using traditional round bottles was evaluated by comparing carbon and nitrogen numbers determined after grinding both plant and soil samples. The square-grinding bottle produced a smaller particle size than did the round bottle and also provided acceptable carbon and nitrogen results in both plant and soil samples while providing an economical approach to grinding large numbers of samples with minimal labor and equipment cost.

Technical Abstract: Obtaining finely ground, homogeneous plant and soil samples for chemical analysis without cross contamination is a major concern when using direct combustion procedures for determination of total nitrogen (N), total carbon (C), and isotope-ratio analysis. A roller-milling device, using square glass bottles instead of round grinding bottles, was evaluated. Rotation of the square bottles on the roller mechanism increased the milling action by the stainless steel rods inside the bottles. The roller-milling device with square grinding bottles resulted in a sample with smaller particles (99.2 % <100 mesh) than with a ball-milling device (83% <100 mesh). The roller-mill provided acceptable results (soil and plant samples ranging from 1.6-43.8% C, 0.5-2.3% N, and 0.3777-1.038 atom% 15N had coefficients of variation ranging from 0.44-1.78, 0.97-1.60, and 0.09-1.43 respectively) while providing an economical approach to grinding large numbers of samples to achieve finely ground, homogeneous samples with minimal labor and equipment costs.

Last Modified: 10/21/2014
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