On-line single droplet deposition for MALDI mass spectrometry

Improving the signal intensity and sensitivity of MALDI mass spectrometry by using nanoliter spots deposited by induction-based fluidics

“…One approach minimizes dispersion of sample materials by etching or drilling small channels on the target [1, 2] or using hydrophobic materials as MALDI plate surfaces [3][4][5][6]. A second approach uses microdispensing, including use of capillary tubes [7][8][9][10], piezoelectric techniques [11][12][13][14], electrodynamic methods [15], and acoustic ejection [16]. This general approach improves MALDI for imaging [14,16], on-line analysis [13,17], and concentration enhancement by microextraction [10].…”

“…A second approach uses microdispensing, including use of capillary tubes [7][8][9][10], piezoelectric techniques [11][12][13][14], electrodynamic methods [15], and acoustic ejection [16]. This general approach improves MALDI for imaging [14,16], on-line analysis [13,17], and concentration enhancement by microextraction [10]. Common in both approaches [1-12, 15, 17] is the concept that the sensitivity of MALDI-MS increases when small sample spots are used and that the search for "hot spots" within the sample area becomes more productive when solid matrices are used.…”

Development of an automated digestion and droplet deposition microfluidic chip for MALDI-TOF MS

“…The small sample and reagent requirements, rapid analysis times, high throughput processing capabilities, and low operating costs are among the driving forces for the development of these systems [5][6][7][8]. Different microfluidic devices have been applied to specific aspects of protein processing, in particular, protein purification and separation, protein digestion, and protein identification by mass spectrometry [9].There have been a number of approaches to on-line and off-line matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) integrated to chipbased devices [10][11][12][13][14][15][16][17][18]. The primary advantage of the MALDI approach compared with electrospray ionization (ESI) when coupling to microfluidic chips is the potential for multiplexing [19].…”

“…There have been a number of approaches to on-line and off-line matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) integrated to chipbased devices [10][11][12][13][14][15][16][17][18]. The primary advantage of the MALDI approach compared with electrospray ionization (ESI) when coupling to microfluidic chips is the potential for multiplexing [19].…”

Rapid lipid profiling of bacteria by online MALDI-TOF mass spectrometry

“…Many techniques and methods have been used to introduce the liquid sample into MALDI-TOF mass spectrometers to achieve online MALDI analysis [18][19][20][21][22]. Li and Wang used a capillary to deliver the liquid sample directly to the MALDI sample probe [18,19].…”