MALDI is simpler, the MALDI target is a metallic target (usually steel) either mirror polished or matte (and rarely patterned) and is simple that. So is a cost based issue in my view.

Dear Liew,

Indeed, the SALDI (surface assisted laser desorption/ionization) methods (including DIOS) work good in obtaining mass spectra of small molecules. Nevertheless, they have some drawbacks. First of all, ionization in SALDI conditions is not so soft when compared with ESI or MALDI, many compounds can fragment due to high intensity laser radiation not absorbed by matrix. It is especially important for such labile objects as peptides or proteins. Second, in the absence of proton source the ionization of different compounds occurs due to cationization with contaminant ions such as sodium or potassium. It makes results obtained less predictable and less repeatable.

Hi Liew, in addition to the appropriate answers given above, the LC [or CE] separation actually provides more capability. While DIOS has been more sensitive for SOME cases, that's not universally true in mixtures - which LC or CE can resolve. Therefore you are overwhelmingly more likely to be able to avoid sample preparation with a hyphenated technique and thereby increase sensitivity. We see this all the time when we are reviewing data where the experiment has been well set up. Additionally, the quantitative aspects of MALDI are poorer than ESI.

Hi there,

Everyone's answers are really helpful, I could finally understand why they used LC-ESI more often now. I have been wondering why DIOS has not been used despite its capabilities to detect lower mass molecules, especially since there are no background ions to skew readings. I took a look at publications showing the graph resulting from both methods, and it is actually easier to analyse the one from LC-ESI due to the separation as well as loads of experimental data to compare with.

Thanks!