Table 1: Precision study.

DrugConcentration ( g/mL)Intraday precision Calculated concentration ± S.D. ( gmL−1), R.S.D.Interday precision calculated concentration ± S.D. ( gmL−1), R.S.D.

Risperidone20 , 1.04 , 1.22
30 , 0.89 , 0.88
40 , 0.52 , 0.68