. Author manuscript; available in PMC: 2010 Oct 1.

Published in final edited form as: Anal Chem. 2009 Oct 1;81(19):8109–8118. doi: 10.1021/ac901313m

Table 1.

IRMPD efficiencies of model peptides dissociated in the low pressure and high pressure cells of the dual LIT

Peptide	MW (Da)	Charge State	Low Pressure Cell			High Pressure Cell
Peptide	MW (Da)	Charge State	Irradiation Time (ms)	q-value	Dissociation Efficiency (%)^a	Irradiation Time (ms)	q-value	Dissociation Efficiency (%)^a

YGGFLK	638.4	2+	15.0	0.10	98	250.0	0.25	2.6
		1+	25.0	0.10	94	250.0	0.25	1.5
		1+	35.0	0.07	6	---	---	---
		1+	50.0	0.07	94	---	---	---

ASHLGLAR	823.5	2+	12.5	0.10	93	250.0	0.25	2.9
		1+	40.0	0.06	70	250.0	0.25	3.0
		1+	50.0	0.06	82	---	---	---

FSWGAEGQR	1035.5	2+	12.5	0.09	98	250.0	0.25	6.3
FSWGAEGQR	1035.5	1+	25.0	0.06	80	250.0	0.25	0.8

DRVYIHPF (angiotensin II)	1045.5	3+	7.5	0.10	97	250.0	0.25	26
		2+	15.0	0.10	96	250.0	0.25	1.3
		1+	25.0	0.10	92	250.0	0.25	4.3

RPPGFSPFR (bradykinin)	1059.6	3+	7.5	0.10	98	250.0	0.25	94
		2+	17.5	0.09	92	250.0	0.25	0.9
		1+	20.0	0.09	96	250.0	0.25	4.9

RPKPQQFFGLM-NH₂ (substance P)	1346.7	3+	5.0	0.10	97	250.0	0.25	96
		3+	---	---	---	50.0	0.10	87
		2+	17.5	0.07	93	250.0	0.25	2.6
		1+	30.0	0.07	96	250.0	0.25	2.7

ADSGEGDFLAEGGGVR (fibrinopeptide A)	1535.7	3+	12.5	0.09	99	250.0	0.25	57
		2+	25.0	0.06	99	250.0	0.25	1.3
		2+	12.5	0.09	94	---	---	---
		1+	25.0	0.06	91	250.0	0.25	3.0

AGCKNFFWKTFTSC (somatostatin-14)	1636.7	3+	12.5	0.09	97	250.0	0.25	5.4
		2+	13.5	0.09	90	250.0	0.25	0.9
		2+	22.5	0.06	90	---	---	---
		1+	25.0	0.06	93	250.0	0.25	22

GIGAVLKVLTTGLPALIS WIKRKRQQ-NH₂ (melittin)	2844.8	5+	9.0	0.09	96	250.0	0.25	17
		4+	20.0	0.07	98	250.0	0.25	1.3
		3+	15.0	0.10	96	250.0	0.25	3.0
		2+	25.0	0.07	98	250.0	0.25	14

Dissociation efficiencies were calculated using eq. (1) for each individual IRMPD mass spectrum.