Organophosphorus flame retardants and plasticizers in water and air II. Analytical methodology

Increasing usage of several organophosphate esters (OPEs), as well as their systematic presence indoors and in water samples, requires development of appropriate analytical procedures to understand their environmental distribution and to identify their transformation and degradation by-products. We review the latest analytical methods for the determination of OPEs in water, air and particulate material (e.g., sediments and dust), covering various extraction and clean-up techniques, as well as their determination by gas chromatography-nitrogen-phosphorus detection (GC-NPD), GC-mass spectrometry (GC-MS) and liquid chromatography-MS (LC-MS). Besides phosphoric acid triesters, we also consider diesters and monoesters. We discuss thoroughly the merits and the limitations of these methodologies. We also highlight some challenging issues in the determination of OPEs (e.g., the need of certified reference materials, isotopically-labeled surrogates of the congeners causing the greatest concern, and standards for the phosphoric acid diesters and monoesters. Finally, we point to potential future trends in the analytical determination of OPEs. A previous review covering the environmental occurrence and fate of OPEs was published in the last issue of this journal [T. Reemtsma, J.B. Quintana, R. Rodil, M. García-López, I. Rodríguez, Trends Anal. Chem. 27 (2008)].