Polycyclic aromatic hydrocarbons in rice grain dried by different processes: evaluation of a quick, easy, cheap, effective, rugged and safe extraction method

Abstract

This study aims at developing a method for the determination of 16 polycyclic aromatic hydrocarbons (PAHs) in rice grain samples by combining the quick, easy, cheap, effective, rugged, and safe (QuEChERS) method and determination by gas chromatography-mass spectrometry (GC-EI-MS). Quantification limits ranging from 1 to 5μgkg(-1) were obtained. Recoveries ranged from 70% to 106% for most of the 16 PAHs under analysis. The optimised methodology was applied to assess safety concerning the content of PAHs in white and parboiled rice samples, dried by gas and wood burning. Although benzo(a)pyrene, the marker used for evaluating the carcinogenic risk of PAHs in food, was not detected in the samples, naphthalene and phenanthrene were detected in all of them. Since cereals have been shown to be an important source of PAHs in the diet, methods that perform the evaluation of the quality of this food group become relevant.

Keywords: GC–EI–MS; Polycyclic aromatic hydrocarbons; QuEChERS; Rice.