PQRI Elemental Impurities Study - Total Digestion Method

This procedure measured impurity levels of ICH Q3D Class 1 and 2A elements (As, Cd, Hg, Pb, Co, Ni, and V) in PQRI Interlab Study tablets. It was intended to be used by selected laboratories participating in the Interlaboratory Study. Samples were acid-digested with a mixture of nitric, hydrochloric, phosphoric, and fluoroboric acids in a microwave digestion system. The resulting solutions were diluted and then analyzed by inductively coupled plasma mass spectrometry (ICP-MS) using an external calibration curve and an internal standard specific to each analyte. Results were reported in ppm (μg/g).