ICP-MS Determination of 10 Impurity Elements in Lacosamide Injection

The Lacosamide injection sample was diluted to 100.0 mL with diluent. ICP-MS was applied to the determination of 10 impurity elements, i.e. Li, V, Co, Ni, Cu, As, Cd, Sb, Hg and Pb in the sample solution. Internal standard method was used for quantitative. Detection limits (3s/k) of the 10 impurity elements were in the range of 0.002-0.040 μg·L^-1 and lower limits of determination (10s/k) were in the range of 0.007-0.120 μg·L^-1. On the base of blank sample, test for recovery was made by standard addition method; values of recovery found were in the range of 95.2%-124%, with RSDs (n=6) of determined values in the range of 1.0%-2.5%. Through risk assessment and daily maximum recommended dose, the daily allowable exposure and content limit of each impurity element in Lacosamide injection were determined.