Non-chromatographic inorganic arsenic speciation in rice by spectrophotometry using silver nanoparticles as platform sensor.

Abstract

Significant arsenic (As) contents have been reported in rice. The most toxic As species, inorganic arsenic (iAs), is one of the most common species in rice. Thus, it is important monitor iAs in this matrix. In this work, plasmonic silver nanoparticles were functionalized with polyethylene glycol (Ag@PEG) and used as a sensor platform for iAs quantification in rice by spectrophotometry. The proposed method showed good linearity in a range between 1 and 15 μg kg-1; high selectivity for iAs; LOD and LOQ of 0.66 and 1.99 μg kg-1, respectively. The trueness of the method was evaluated by SRM NIST 1568b analysis (105 % of iAs recovery) and by comparing the results with HPLC-ICP-MS analysis (107 %). The As and iAs content in the rice samples varied between 119 and 605 μg kg-1 and 15.7-110 μg kg-1, respectively. The proposed method is simpler, faster, lower-cost and greener compared to conventional analytical methods to quantify iAs.