Development of certified reference material for quantification of two pesticides in brown rice.

Brown rice powder certified reference material, NMIJ CRM 7504-a, for the analysis of pesticide residues was developed by the National Metrology Institute of Japan, part of the National Institute of Advanced Industrial Science and Technology. Brown rice sample was harvested to contain the pesticides such as etofenprox and fenitrothion, and that was collected from a field in Ibaraki Prefecture in Japan. The certification was carried out using multiple analytical methods such as pressurized liquid extraction, homogenization, and solid-liquid extraction (shaking); the values of target pesticides were obtained by isotope dilution mass spectrometry. Certified values were 0.19 +/- 0.05 mg/kg and 0.109 +/- 0.017 mg/kg for etofenprox and fenitrothion, respectively.