IRM Analyse date Mean (mg kg-1) σsam σp Homogeneity (σsam/σp)* Stability (|X-Y|/ σp)* Calf heart (X, n = 20): 23/08/2012 (Y, n = 06): 16/11/2012 0.138 0.147 0.004 0.030 0.13 0.29 Beef Kidney (X, n = 20): 02/08/2012 (Y, n = 06): 16/11/2012 1.24 1.28 0.048 0.192 0.25 0.23 Calf liver (X, n = 20): 03/08/2012 (Y, n = 06): 16/11/2012 3.41 3.52 0.031 0.454 0.07 0.24 Calfmuscle (X, n = 20): 24/08/2012 (Y, n = 06): 16/11/2012 3.88 3.86 0.030 0.869 0.03 0.02 Calf brain (X, n = 20): 23/08/2012 (Y, n = 06): 16/11/2012 7.14 7.38 0.059 0.850 0.07 0.27 *Critical value > 0.3

Table 3: Homogeneity and stability study for TiO2 NPs in IRMs, analyse performed by ICP-MS Agilent 7700x with He mode.