Nanomanipulation‐Coupled Nanospray Mass Spectrometry Applied to the Extraction and Analysis of Trace Analytes Found on Fibers*

Abstract

This article presents the novel instrumentation of nanomanipulation coupled to nanospray ionization-mass spectrometry, which is used to directly probe trace analytes found on individual fibers. The low detection limits and sample volumes associated with nanospray ionization-mass spectrometry make it the ideal instrument to implement for trace analysis. Nanospray ionization-mass spectrometry, coupled with the nanomanipulator, allows for the direct probing of trace particulates on fibers. The technique is demonstrated by dissolving an electrostatic particle of cocaine from a fiber, collecting the analyte solution in a nanospray tip, and transferring the tip directly to the mass spectrometer to complete analysis. The utility of this technique is evident through the minimal sample preparation and short analysis time. The use of nanomanipulation coupled to nanospray ionization-mass spectrometry could improve on current trace particulate analysis by reducing both detection limits and sample size required to complete analysis.

Visualization of Lipid Droplet Composition by Direct Organelle Mass Spectrometry

“…Furthermore, it is possible to envision this approach expanded to support broad-based MS analysis of other macromolecules in organellar samples, such as proteomic or general metabolomic studies, placing this DOMS approach at the forefront of biochemical analysis with microscale resolution. Although the positioning resolution of the L200 surpasses many commercially available nanomanipulators, the relative ease of combination of a standard robotic-controlled microscope stage with conventional light microscopy and standard MS instruments (nanospray source mounted on an ion-trap or triple quad MS) provides a high level of flexibility to achieve diverse and specialized systems (26,27). In this case, only a single end effector holding a glass nanospray emitter was necessary for sampling purified LDs; however, there are multiple ports on the L200 that could be used as molecular "tweezers" and low impedance electrical positioners (26) that might be advantageous for handling and/or sampling cellular constituents on stage, either from purified populations as was shown here, or perhaps even in situ by microdissection of whole tissue samples.…”

“…A multifaceted nanomanipulator, previously demonstrated to extract peptides from a single bead (26) and extract and analyze trace fiber analytes (27), was equipped with glass nanospray emitters prefilled with organic solvent capable of extracting the lipid contents out of LDs. Here, this approach is illustrated with LDs from diverse plant sources (Gossypium hirsutum and Arabidopsis thaliana).…”

Nanomanipulation-Coupled Matrix-Assisted Laser Desorption/ Ionization-Direct Organelle Mass Spectrometry: A Technique for the Detailed Analysis of Single Organelles

“…We have developed a nanomanipulation workstation capable of collecting trace particles [10][11][12][13], single cells, and subcellular organelles [5,14,15]. The workstation can be equipped with up to four piezoelectric nanopositioners capable of simultaneously utilizing different end effectors, including microgrippers, nanospray emitters, and microelectrodes that perform low impedance electrical characterizations.…”

“…The translational resolution of the nanomanipulator allows for 100 and 5 nm in coarse and fine mode, respectively. Owing to the precise targeting capability, extractions are performed discriminately, removing the need for lengthy chromatographic separations and simultaneously reducing matrix effects [12,13]. This allows extractions to be introduced directly into the mass spectrometer via direct infusion mass spectrometry (DIMS), which reduces additional sample preparation and enables rapid mass analysis.…”

“…Recently, we have shown that the nanomanipulator can be used as a surface-probing technique, direct analyte-probed nanoextraction (DAPNe), to extract drug residue from latent fingerprints [10], individual fibers [13], and trace explosive materials [12], in combination with direct analysis in real time mass spectrometry (DART-MS) [11]. DAPNe has also been utilized for the analysis of document inks, demonstrating the ability to characterize the chemistry of both antique and modern documents without interfering with the integrity of the document [17].…”