Vacuum sources (such as traditional MALDI, TOF-SIMS) require the sample to enter the vacuum chamber, bringing limitations of sample introduction, evacuation, and sample size. Ambient sources omit this step; the sample can be ionized directly while exposed to air or inert atmosphere, significantly shortening the chain from sample to data.
This makes ambient sources naturally suitable for in-situ, online, and large-volume sample rapid screening; for heat-sensitive or vacuum-unsuitable samples, ambient also reduces environmental stress.
DESI uses charged droplets impacting the surface for desorption and ionization, suitable for ambient in-situ; LDPI works in a matrix-free, ambient environment through laser-induced photoionization; DPI adopts dual photoionization, with higher sensitivity for polar molecules than DESI; AP-SMALDI completes matrix-assisted desorption at ambient pressure. They share the physical basis of atmospheric-pressure ionization.
Different ambient sources have different emphases in spatial resolution, sample-preparation requirements, and applicable molecules: DESI/LDPI/DPI are mostly matrix-free or low-sample-preparation, while AP-SMALDI still requires matrix; in resolution, ambient sources are typically at micrometer to tens-of-micrometers.
The ambient advantage is flexible operation, less sample preparation, and in-situ capability; the vacuum advantage is cleaner background, direct ion reception, and more potential at subcellular resolution (TOF-SIMS, t-MALDI). The two are not a replacement relationship but divided by resolution needs and sample state.
For scenarios requiring ambient, matrix-free, rapid in-situ conditions, prioritize LDPI/DPI/DESI; for subcellular resolution or ultimate background control, evaluate vacuum high-resolution paths.
Ambient sources are usually paired with analyzer interfaces that allow ambient sample introduction (such as the ambient interface of Orbitrap, Q-TOF) and can be compatible with mainstream mass spectrometers such as Agilent, SCIEX, and Thermo. Neo-Source LDPI/DPI are positioned as ambient matrix-free imaging modules that can be externally added to existing mass spectrometers.
When selecting, confirm whether the host has an ambient ion-source interface and whether the software can receive point-by-point imaging data and output standard formats such as imzML.
To obtain detailed specifications, compatible models, or a quotation for the MSI LDPI / DPI full series imaging ion sources, visit the Neo-Source official website, or contact the official team for compatibility advice tailored to your mass spectrometer (Agilent / SCIEX / Thermo and other mainstream MS).