Table I. Shown are the compounds and the precursor ions used in this work.

The product ion yield is given by (the sum of all assigned product ions divided by the sum of all the ions in the spectrum including the precursor)·100. The percent of SO₃ loss experienced during the CID of the given precursor is calculated by summing up all the intensities of the fragments resulting from SO₃ loss and dividing this value with the sum of the intensities of all assigned fragment ions excluding the precursor and then multiplying the result by 100. Number of free protons in this work is calculated using this formula ((number of SO₃ + carboxyl groups in the compound) − (precursor charge + number of Na⁺ in it)).

Compound, no. of sulfates, and precursor with its m/z	% product ion yield	% of SO3 loss product ions	No. of free protons	Sulfate/disaccharide
dp4 (T1) 5S, [M − 7H + 4Na]3− m/z 386.29	54	<1	0	2.5
dp4 (T3) 5S, [M − 7H + 4Na]3− m/z 386.29	42	2	0	2.5
dp4 (T1) 5S, [M − 6H + 2Na]4− m/z 278.48	41	10	1	2.5
dp4 (T3) 5S, [M − 6H + 2Na]4− m/z 278.48	30	21	1	2.5
dp4 (T2) 6S, [M − 7H + 3Na]4− m/z 303.96	43	12	1	3
dp6 8S, [M − 11H + 7Na]4− m/z 450.20	55	1	0	2.7
dp8 11S, [M − 14H + 7Na]7− m/z 339.25	56	23	1	2.8
dp10 8S, [M − 13H + 7Na]6− m/z 412.66	44	11	0	1.6
dp7 7S, [M − 10H + 5Na]5− m/z 376.39	50	15	0	2
dp12 10S, [M − 16H + 9Na]7− m/z 430.85	41	14	0	1.7
dp12 5S, [M − 11H + 4Na]7− m/z 358.03	62	7	0	0.8
dp11 5S, [M − 9H + 3Na]6− m/z 384.87	62	7	1	0.9
dp10 4S, [M − 9H + 3Na]6− m/z 344.70	63	6	0	0.8