HPLC Analysis of Sildenafil and Impurities on Chromolith^® Performance (4.6 mm I.D. columns)

Chromolith^® Performance RP-18 endcapped, 10 cm x 4.6 mm I.D. (2 columns in series) (1.02129.0001)

A] acetonitrile; [B] na-phosphatbuffer 20mM pH=3.0;

Initial composition: 0-8min 55%A to 45%B isocratic, flow increases from 0.5 to 1ml/min, 8,1-20min 65%A to 35%B isocratic, flow 3ml/min.

1450 psi (100 bar)

ambient

254 nm cell: 11 μL

0.5 μL

Methoxyamin (1mg/ml), Sildenafil Citrat (5mg/ml), Amidin (1mg/ml), Imidon 1 (0.5mg/ml), Imidon 2 (0.5mg/ml), Thiophenethylester (1mg/ml), Acyl-BT-Ester (2mg/ml),Aminacid (0,5mg/ml), CHT-Ester (1mg/ml), Acyl-CHT-Ester (2mg/ml),Aminester (0.2mg/ml), Imidochlorid 1 (0.3mg/ml), Imidochlorid 2 (0.2mg/ml)

Chromolith is a registered trademark of Merck KGaA, Darmstadt, Germany