. Author manuscript; available in PMC: 2008 Feb 4.

Published in final edited form as: Anal Chem. 2005 Jul 15;77(14):4439–4447. doi: 10.1021/ac058000a

Table 2.

Comparative Study of the Anionic Phosphorylated Lipids’ Major Spectral Molecular Ions Observed for the Six Different MALDI Matrixes^a

lipid	DHB	50/50 αCHCA/DHB, 0.1% TFA	PNA	PNA, 0.1% TFA	PNA + butyric acid	PNA + butyric acid, 0.1% TFA
16:0/18:1-PG	[PG + Na]⁺	[PG + 2Na - H]⁺	[PG + Na]⁺	[PG + Na]⁺	[PG + Na]⁺	[PG + Na]⁺
	[PG + 2Na - H]⁺		[PG + 2Na - H]⁺	[PG + 2Na - H]⁺	[PG + 2Na - H]⁺
	[PG - HG]⁺			[PG - HG]⁺
16:0/18:1-PS	[PS + Na]⁺	[PS - HG]⁺	[PS + Na]⁺	[PS + Na]⁺	[PS + Na]⁺	[PS - HG]⁺
	[PS + 2Na - H]⁺			[PS - HG]⁺
16:0/18:1-PA	[PA + Na]⁺	[PA + 2Na - H]⁺	very low signal	[PA + 2Na - H]⁺	[PA + Na]⁺	very low signal
	[PA + 2Na - H]⁺			[PA + Na]⁺	[PA + 2Na - H]⁺
16:0/18:2-PI	[PI + Na]⁺	[PI + 2Na - H]⁺	[PI + Na]⁺	[PI + Na]⁺	[PI + Na]⁺	[PI + Na]⁺
	[PI + 2Na - H]⁺	[PI + Na]⁺	[PI + 2Na - H]⁺	[PI + 2Na - H]⁺	[PI + 2Na - H]⁺	[PI + 2Na - H]⁺

For abbreviations, see text. HG = headgroup.