Limits for the detection of (poly-)phosphoinositides by matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF MS)

Detection of Adducts with Matrix Clusters in the Positive and Negative Ion Mode MALDI-TOF Mass Spectra of Phospholipids

“…2(b), and it can be observed that the signal intensities increase with increasing PL concentration. A signal arising from the matrix adduct of SOPC was not detectable at the lowest concentration of this PL, most probably due to already observed higher detection limits for acidic PLs, i. e. higher concentrations of them are required for their detection in the spectra in comparison to the neutral ones [10]. On the other hand, the intensity of the matrix adduct of POPC was rather high even at the lowest concentration.…”

Elicitor-Activated Phospholipase A2 Generates Lysophosphatidylcholines That Mobilize the Vacuolar H+ Pool for pH Signaling via the Activation of Na+-Dependent Proton Fluxes

“…Although not yet widespread in plant science, the potential of this fast and direct analysis of complex lipid mixtures has been established by methodological work and its application to human cells (Schiller et al, 2000;Müller et al, 2001;Petkovi et al, 2001). Compared with protein analysis, MALDI-TOF MS of lipids allows a more reliable quantification because the matrix and the analyte are easily soluble in the same solvent and thus form a homogeneous phase.…”

“…Quantification of the compounds detected was based on signal-tonoise (S/N) ratios as described by Müller et al (2001). The signal height (S H ) of the mass peak of interest was related to the noise amplitude (N A ), that is, the span between maximum and minimum signal height in a region that contained pure noise (usually 1040 to 1140 D), using the formula S/N ϭ 2.5 (S H Ϫ 0.5 N A )/N A ϫ 2.5.…”

Combined application of TLC and matrix-assisted laser desorption and lonisation time-of-flight mass spectrometry (MALDI-TOF MS) to phospholipid analysis of brain

“…Trace (2a) corresponds to the sphingomyelin fraction, trace (2b) to PC, trace (2c) to phosphatidylserine (PS), trace (2d) to phosphatidylinositol (PI) and (2e) to the phosphatidylethanolamine (PE) fraction, respectively. According to their occurrence in brain and their charge characteristics, individual PL are detected with different sensitivities [21]. This is obvious if the intensity of the characteristic matrix peaks at m/z = 551 and m/z = 727 (marked with asterisks) are compared with the peak of interest [19].…”