In order to determine the recovery of inorganic INSs in the high-density isolate and if inorganic INSs contaminate the low-density isolate, tests were conducted with K-feldspar (density = 2.44 -2.63 g cm -3 ), an effective inorganic INS (Figure ). For this case, the freezing curves for the high-density isolates partially overlapped with the unprocessed samples, but on average were shifted to slightly colder (~1 °C)