Fast HPLC-MS/MS Method for Determining Penicillin Antibiotics in Infant Formulas Using Molecularly Imprinted Solid-Phase Extraction

Table 3

MRM transitions of each analyte and collision energy (CE) for mass spectrometry detection and chromatographic retention time.

Compound	Mw	Precursor ion	Fragment ion	CE (volts)	RT
Amoxicillin	365.4	366	349	13	2.1
			114	25
Oxacillin	401.4	402	144	33	14.5
			186	21
Cloxacillin	435.9	436	178	31	14.9
			220	21
Penicillin G	334.4	335	217	17	12.9
			202	31
Penicillin V	350.4	351	229	19	13.7
			257	17
Ampicillin	349.4	350	106	21	6.4
			160	9
Dicloxacillin	470.3	470	212	33	15.7
			254	23
Nafcillin	414.4	415	199	17	15.2
			171	51

CE: collision energy in volts.