Chromatography-mass spectrometry determination of alkyl methylphosphonic acids in urine.

The potentials of different chromatography-mass spectrometry methods for the determination of alkyl methylphosphonic acids (AMPAs)-the chemical markers of nerve agents in urine-are compared. The gas chromatography-mass spectrometry (GC-MS) characteristics of various volatile AMPA derivatives are studied. The preference of perfluorobenzyl derivatives over methyl, trimethylsilyl and tert-butyldimethylsilyl esters for the GC-MS determination of AMPAs in urine is demonstrated. An optimal technique for the determination of AMPAs in urine is HPLC combined with high-resolution MS mass spectrometry with the isotope-labeled forms of target compounds as internal standards. The detection limits of AMPAs in the proposed analytical procedures vary from 0.1 to 1.0 ng/mL. [ABSTRACT FROM AUTHOR]