LC/MS analysis of cisplatin effects on ceramide and sphingomyelin. Cells were treated with cisplatin (5 μg/ml) for 15, 30, 60, or 180 min. After Bligh Dyer extraction of lipids, the different treatment groups were subjected to mass spectrometric analysis as indicated in Materials and methods. Sphingolipids measurements were normalized to total phospholipids. Shown are the normalized results for (A) total ceramide, (B) total SM, (C) C₁₆ and C_24:1-ceramide, and (D) C₁₆ and C_24:1-SM. Ceramide and SM results represent averages ± S.E. from three independent experiments.