Location: Integrated Cropping Systems ResearchTitle: Inter-laboratory validation of standardized method to determine permeability of plastic films Author
|Qian, Yaorong - Us Environmental Protection Agency (EPA)|
|Ajwa, Husein - University Of California|
|Qin, Ruijun - University Of California|
|Sances, Frank - Pacific Ag Research, Inc|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/17/2012
Publication Date: 8/19/2012
Citation: Papiernik, S.K., Yates, S.R., Qian, Y., Ajwa, H., Gao, S., Qin, R., Sances, F., Spokas, K.A. 2012. Inter-laboratory validation of standardized method to determine permeability of plastic films. 244th American Chemical Society National Meeting, August 19-23, 2012, Philadelphia PA. AGRO 80, vol. 82, p. 101.
Technical Abstract: To support regulations controlling soil fumigation, we are standardizing the laboratory method we developed to measure the permeability of plastic films to fumigant vapors. The method was validated using an inter-laboratory comparison with 7 participants. Each participant evaluated the mass transfer coefficient (h) of multiple fumigant compounds through 4 films of varying permeability. Standard methods were used to determine outliers, usually 1 value per analysis. For film-chemical combinations with h>1 cm h-1 (relatively high permeability), the coefficient of variation of h values reported by individual participants was 0.05 (for methyl bromide) to 0.3 (for trans-1,3-D). For a film with at least 100 times lower permeability, the coefficient of variation of h values ranged from 0.1 to 1.1. Results of the round-robin test show that h values can be measured with precision, even for low-permeability films, indicating that this method is robust.