Determination of phosphine in plant materials: method optimization and validation in interlaboratory comparison tests.
J Agric Food Chem
; 62(9): 2049-55, 2014 Mar 05.
Article
in En
| MEDLINE
| ID: mdl-24564743
ABSTRACT
The optimization and validation of a method for the determination of phosphine in plant materials are described. The method is based on headspace sampling over the sample heated in 5% sulfuric acid. Critical factors such as sample amount, equilibration conditions, method of quantitation, and matrix effects are discussed, and validation data are presented. Grinding of coarse samples does not lead to lower results and is a prerequisite for standard addition experiments, which present the most reliable approach for quantitation because of notable matrix effects. Two interlaboratory comparisons showed that results varied considerably and that an uncertainty of measurement of about 50% has to be assessed. Flame photometric and mass spectrometric detection gave similar results. The proposed method is well reproducible within one laboratory, and results from the authors' laboratories using different injection and detection techniques are very close to each other. The considerable variation in the interlaboratory comparison shows that this analysis is still challenging in practice and further proficiency testing is needed.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Phosphines
/
Plants
/
Plant Extracts
/
Chromatography, Gas
/
Laboratories
Language:
En
Journal:
J Agric Food Chem
Year:
2014
Type:
Article
Affiliation country:
Switzerland