Evaluation of inductively coupled plasma tandem mass spectrometry for determination of as in agricultural inputs with high REE contents

Abstract

In the present work, an inductively coupled plasma-tandem mass spectrometer (ICP-MS/MS) operating in single quadrupole and mass shift modes were evaluated for As determination in mineral fertilizers and agricultural gypsum with high contents of rare earth elements. For MS/MS mode, oxygen was the gas introduced into the octopole reaction system (ORS3). Samples were prepared by microwave-assisted digestion with diluted nitric acid solution. The accuracy was checked by analysis of a fertilizer certified reference material (NIST SRM 695) and by addition and recovery experiments. When operating in single quadrupole mode, recoveries ranged from 59 to 151%; while values obtained by MS/MS mode varied from 81 to 105% when 0.30 mL min-1 O2 was introduced into the ORS3. Limits of detection for As+ in single quadrupole and AsO+ in MS/MS mass shift mode were 6 and 9 ng L-1, respectively.