Detection of biomolecules from solutions with high concentration of salts using probe electrospray and nano-electrospray ionization mass spectrometry

Self Cite

The probe electrospray ionization (PESI) is an ESI-based ionization technique that generates electrospray from the tip of a solid metal needle. In this work, mass spectra for the single-shot PESI were measured as a function of time for a mixture of several analytes with different surface activity values. It was found that the analytes were elecrosprayed in the order of their surface activity. For example, detergent and protein were detected separately and respectively at the first and last stages of electrospray, for a mixed sample of 10 -3 M Triton X100 and 10 -5 M cytochrome c. For human breast cancer tissue, at first proteins such as α and β chains of hemoglobin, were observed as the dominant ions, but just before the liquid droplet on the needle was depleted only lipids were observed, meaning that PESI has the advantage of the suppression effect with analytes being detected separately in the order of their surface activity values.

mentioning

confidence: 96%

“…In addition to these new techniques, we have developed the probe electrospray ionization (PESI) [19][20][21][22][23][24][25], which uses a solid needle or wire as a sampling probe and as an ESI emitter instead of a capillary. PESI was applied to various biological samples, such as mouse liver, mouse brain, salmon egg, plants, etc.…”

mentioning

confidence: 99%

Sequential and Exhaustive Ionization of Analytes with Different Surface Activity by Probe Electrospray Ionization

Mandal

Chen

Hiraoka

2011

Self Cite

“…Some noncapillary tips such as stainless steel needle [6,19], paper [13,[20][21][22][23], and wooden tips [14] enabled direct analysis of raw samples. Hiraoka and co-workers reported the sequential and exhaustive ionization of analytes on solid metal probe [24].…”

Section: E Lectrospray Ionization (Esi) Is a Powerful Massmentioning

confidence: 99%

“…Noncapillary ESI techniques have also been developed. Materials such as wick element [3], copper wire [4], metal needle [5][6][7], optical fiber wired with a metal coil [8,9], surface-modified glass rod [10], nanostructured tungsten oxide [11], and more recently paper [12,13] and wood [14] have been used for sampling and ionization in ESI. Use of noncapillary emitters avoids the problem of clogging that could occur in capillary-based ESI and allows much easier sampling.…”

Section: E Lectrospray Ionization (Esi) Is a Powerful Massmentioning

confidence: 99%

Analytical Properties of Solid-substrate Electrospray Ionization Mass Spectrometry

Yao

2012

Abstract. Conventional electrospray ionization mass spectrometry (ESI-MS) uses a capillary for sample loading and ionization. Along with the development of ambient ionization techniques, ESI-MS using noncapillary emitters has attracted more interest in recent years. Following our recent report on ESI-MS using wooden tips (Anal. Chem. 83, 8201-8207 (2011)), the technique was further investigated and extended in this study. Our results revealed that the wooden tips could serve as a chromatographic column for separation of sample components. Sequential and exhaustive ionization was observed for proteins and salts on wooden tips with salts ionized sooner and proteins later. Nonconductive materials that contain microchannels/pores could be used as tips for ESI-MS analysis with sample solutions loaded to the sharp-ends only, since rapid diffusion of sample solutions by capillary action would enable the tips to become conductive. Tips of inert materials such as bamboo, fabrics, and sponge could be used for sample loading and ionization, while samples such as tissue, mushroom, and bone could form tips to induce ionization for direct analysis with application of a high voltage.

“…It may be hypothesized that compatibility with high salt samples is an inherent property of all ESI post-ionization methods, including MALDESI. Other strategies have been successfully developed to counter the effect of ion suppression by making fundamental changes to the electrospray, including nanoelectrospray ionization (nanoESI) [16] and probe electrospray ionization (PESI) [17].…”

Section: Usda Is An Equal Opportunity Employermentioning

confidence: 99%

Direct Analysis of Triterpenes from High-Salt Fermented Cucumbers Using Infrared Matrix-Assisted Laser Desorption Electrospray Ionization (IR-MALDESI)

Ekelöf

McMurtrie

Nazari

et al. 2016

Abstract. High-salt samples present a challenge to mass spectrometry (MS) analysis, particularly when electrospray ionization (ESI) is used, requiring extensive sample preparation steps such as desalting, extraction, and purification. In this study, infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) coupled to a Q Exactive Plus mass spectrometer was used to directly analyze 50-μm thick slices of cucumber fermented and stored in 1 M sodium chloride brine. From the several hundred unique substances observed, three triterpenoid lipids produced by cucumbers, β-sitosterol, stigmasterol, and lupeol, were putatively identified based on exact mass and selected for structural analysis. The spatial distribution of the lipids were imaged, and the putative assignments were confirmed by tandem mass spectrometry performed directly on the same cucumber, demonstrating the capacity of the technique to deliver confident identifications from highly complex samples in molar concentrations of salt without the need for sample preparation.