ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Rapid determination of fosetyl-aluminium in commercial pesticide formulations by high-performance liquid chromatography

Helen Karasali, Konstantinos M. Kasiotis, and Kyriaki Machera

Laboratory of Chemical Control of Pesticides, Department of Pesticides Control and Phytopharmacy, Benaki Phytopathological Institute, 8 St. Delta Street, Kifissia, 14561, Athens, Greece

E-mail: E.Karassali@bpi.gr

Abstract: An isocratic reversed-phase high-performance liquid chromatographic (RP-HPLC) method with diode array detection (DAD) was developed for the determination of aluminium tris(ethyl phosphonate) (fosetyl-aluminium, fosetyl-Al) in plant-protection products. The method involves extraction of the active ingredient by sonication of the sample with water and direct measurement by RPHPLC. The isocratic RP-HPLC method for the analysis of fosetyl-Al thus developed was then validated for specificity, linearity, precision, and accuracy. The chromatographic peak confirmation was performed by LC-MS using electron spray ionisation in the negative-ion mode. The repeatability of the method, expressed as relative standard deviation (RSD, %), was found to be 0.5 % and the limit of detection was 0.035 mg mL⁻¹. The average recoveries of the three fortification levels varied from 96.7 % to 100.6 % and the RSDs ranged between 2.6 % and 6.3 %. The precision of the method was also considered to be acceptable as the experimental repeatability relative standard deviation (RSD_r) was lower than the RSD_r, calculated using the Horwitz equation. The method is rapid, simple, accurate, cost-effective, and provides a new and reliable means for the analysis of fosetyl-Al in formulated products.

Keywords: HPLC – diode array detector – fosetyl-aluminium – mass spectrometry – ion-pair

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-013-0522-6

Chemical Papers 68 (6) 725–731 (2014)