Direct determination of cadmium in rice flour by laser ablation-ICP-MSElectronic supplementary information (ESI) available: table of Cd concentrations in Japanese rice; plots showing the pre-ablation effect on 13C and 111Cd signal intensities and the spot-size effect on 111Cd signal intensities in NIES 10b; calibration plots. See http://www.rsc.org/suppdata/ja/b3/b310827a/

Direct determination of cadmium in rice flour by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is described. This superior quantitative method needs no conventional laborious sample pretreatment such as decomposition and extraction. To construct the calibration line and estimate the detection limit, three certified reference materials for rice flour, NIES nos. 10a, 10b and 10c, were used and contaminated with three different concentrations of cadmium (0.023, 0.32 and 1.82 mg kg−1, respectively). These three kinds of rice flour were finely ground and pressed into disks for analysis. The calibration line showed good linearity in the range 0.023–1.82 mg kg−1. The determination did not require internal standardization and no significant interference was observed.