TABLE 1

Summary of amlodipine metabolites detected in HLM by LC/MS

Metabolite	RT	Identity	MH⁺	MSⁿ Spectral Data	Racemic Amlopdipine	S-amlodipine
	min
M1	10.06	P-2H-CH₂	393	MS²: 376, 350, 332, 314, 304;	√	−
M1	10.06	P-2H-CH₂	393	MS³ (332): 304, 286	√	−
M3	11.79	P + O	425	MS²: 379, 336, 294, 364;	√	√
M3	11.79	P + O	425	MS³ (336): 318, 304, 180	√	√
M4	12.02	P-2H-C₂H₄NH-C₂H₄	336	MS²: 318,286;	√	√
M4	12.02	P-2H-C₂H₄NH-C₂H₄	336	MS³ (318): 286	√	√
M5	12.06	P + O	425	MS²: 417, 390, 379, 336, 294;	√	√
M5	12.06	P + O	425	MS³ (336): 318,304,286,181	√	√
M6	12.06	P-CH₂	395	MS²:352, 334, 306,180;	√	−
M6	12.06	P-CH₂	395	MS³ (180): 163,144	√	−
M8	12.71	P + O	425	MS²: 390, 379, 336, 294, 364;	√	√
M8	12.71	P + O	425	MS³ (336): 318, 304, 248,181	√	√
M9	13.57	P-2H	407	MS²: 390, 364, 346, 318, 286;	√	√
M9	13.57	P-2H	407	MS³ (346): 318, 286.	√	√
M10	17.88	P-2H-NH+O	408	MS²: 346,318, 286, 390;	√	√
M10	17.88	P-2H-NH+O	408	MS³ (346): 318, 286	√	√
M12	18.38	P-2H-NH+2O-2H	422	MS²: 376, 346, 318, 286;	√	√
M12	18.38	P-2H-NH+2O-2H	422	MS³ (346): 318, 286	√	√
P	15.02	Amlodipine	409	MS²: 392, 346, 348, 320, 294, 238;	√	√
P	15.02	Amlodipine	409	MS³ (392): 360, 346	√	√

MH⁺, protonated molecular ions; MSⁿ, multiple stage MS/MS fragmentation; RT, retention time.