Table 1.

Mass spectrometry parameters used in the determination of DMP, DMTP, tramadol-HCl and O-desmethyl tramadol-HCl

Compound	Precursor ion (m/z)	Product ion (m/z)	Declustering potential	Entrance potential	Collision energy	Collision cell exit potential
DMP	125ac	79	−35	−10	−35	−5
	125ad	63	−35	−10	−35	−5
DMTP	141ac	126	−46	−10	−20	−5
	141ad	95	−46	−10	−36	−5
	141ad	79	−46	−10	−20	−5
Tramadol-HCl	264bc	58	46	10	27	9
O-desmethyl tramadol-HCl	250bc	58	46	10	27	9

^aMass spectrometer operated in negative mode; source temperature, 550 °C; ion spray voltage, −4200 V.

^bMass spectrometer operated in positive mode; source temperature, 450 °C; ion spray voltage, 5500 V.

^cQuantification transition

^dConfirmation transition