Plant and Soil

, Volume 369, Issue 1, pp 509–513

Milling plant and soil material in plastic tubes over-estimates carbon and under-estimates nitrogen concentrations


    • IBESUniversity of Aberdeen
    • ACESUniversity of Aberdeen
    • The James Hutton Institute
  • A. H. Jean Robertson
    • The James Hutton Institute
  • Andrew A. Meharg
    • IBESUniversity of Aberdeen
  • Robin J. Pakeman
    • The James Hutton Institute
  • David Johnson
    • IBESUniversity of Aberdeen
  • Sarah J. Woodin
    • IBESUniversity of Aberdeen
  • René van der Wal
    • ACESUniversity of Aberdeen
Regular Article

DOI: 10.1007/s11104-013-1599-y

Cite this article as:
Smith, S.W., Robertson, A.H.J., Meharg, A.A. et al. Plant Soil (2013) 369: 509. doi:10.1007/s11104-013-1599-y


Background and aims

Milling of plant and soil material in plastic tubes, such as microcentrifuge tubes, over-estimates carbon (C) and under-estimates nitrogen (N) concentrations due to the introduction of polypropylene into milled samples, as identified using Fourier-transform infra-red spectroscopy.

Methods and results

This study compares C and N concentrations of roots and soil milled in microcentrifuge tubes versus stainless steel containers, demonstrating that a longer milling time, greater milling intensity, smaller sample size and inclusion of abrasive sample material all increase polypropylene contamination from plastic tubes leading to overestimation of C concentrations by up to 8 % (0.08 g g−1).


Erroneous estimations of C and N, and other analytes, must be assumed after milling in plastic tubes and milling methods should be adapted to minimise such error.


CarbonFourier-transform infrared spectroscopyGrindingMicrocentrifuge tubesMillingNitrogen

Copyright information

© Springer Science+Business Media Dordrecht 2013