Table 1.

Diagnostic ion intensities for CSA and DS dp4-dp10. The intensities are reported as percentages of the total ion intensity of the tandem mass spectrum excluding the precursor ion intensity. The ratio column compares the intensity of diagnostic ions for DS to those from CSA. The protons column lists the number of ionizable protons in the product ions.

dp	Precursor ion	2,4An	protons	CSA	DS	Ratio
4	[M-3H]3−	2,4A3	1	17.1 ± 0.7	4.7 ± 0.2	0.28
6	[M-5H+Na]4−	2,4A3	1	2.02 ± 0.06	0.96 ± 0.04	0.48
		[2,4A5+Na]2−	1	6.8 ± 0.7	0.32 ± 0.02	0.05
8	[M-7H+2Na]5−	2,4A3	1	1.17 ± 0.03	0.32 ± 0.03	0.28
		[2,4A5+Na]2−	1	0.64 ± 0.04	0.08 ± 0.003	0.13
		2,4A5+2Na	1	0.11 ± 0.01	0.00	0.00
		[2,4A7+2Na]3−	1	2.1 ± 0.2	0.07 ± 0.005	0.03
10	[M-9H+3Na]6−	2,4A3	1	0.66 ± 0.06	0.24 ± 0.01	0.36
		[2,4A5+Na]2−	1	0.17 ± 0.02	0.00	0.00
		[2,4A7+2Na]3−	1	0.29 ± 0.02	0.00	0.00
		[2,4A7+3Na]2−	1	0.26 ± 0.01	0.00	0.00
		[2,4A9+3Na]4−	1	0.63 ± 0.10	0.00	0.00