Strategy of Sample Preparation for Arsenic Determination in Mineral Fertilizers

Author(s)

Machado, Raquel C. ; Pereira-Filho, Edenir R. ; Nogueira, Ana Rita A.

• Document type: Journal article
• Source: Journal of the Brazilian Chemical Society; v. 27, n. 7, p. 1273-1278, JUN 2016.
• Web of Science Citations: 7

Abstract

A method for determination of arsenic in mineral fertilizers by continuous flow hydride generation atomic absorption spectrometry (CF-HG-AAS) was developed by using diluted acid and digester block with perfluoroalkoxy (PFA) tubes to sample preparation. An additional sample preparation procedure using microwave-assisted digestion was evaluated and compared with the proposed procedure. A full factorial design was applied to investigate the effect of the variables and the best conditions found were 7 mol L−1 HNO3 + 30% (m/m) H2O2 as reagents, 4 h of digestion and concentration of reagents diluted 1:1. The effect of concomitants on the analytical signal of arsenic was investigated and no one significant interference was observed, with recoveries ranged from 97 to 103%. The accuracy of proposed method was evaluated by certified reference material (NIST SRM 695) and recovery of 95% was obtained. The arsenic concentration (8.9 ± 0.2 mg kg−1) found in the fertilizer is below of maximum concentration established by Brazilian legislation. (AU)

• FAPESP's process: 13/26672-5 - Development of procedures to As, Ba, Cd, Cr, Pb and Si determination in fertilizer samples by using microwave inductive plasma optical emission spectrometry (MIP OES)
• Grantee: Raquel Cardoso Machado
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 15/14488-0 - Analytical method development for quality determination of fertilizers and tanning waste
• Grantee: Ana Rita de Araujo Nogueira
• Support Opportunities: Regular Research Grants