Direct Characterization of Bulk Samples by Internal Extractive Electrospray Ionization Mass Spectrometry

Abstract

A straight-forward analytical strategy called internal extractive electrospray ionization mass spectrometry (iEESI-MS), which combines solvent extraction of chemicals inside a bulk sample with in situ electrospray ionization mass spectrometry, has been established to directly characterize the interior of a bulk sample with molecular specificity. The method allows both qualitative and quantitative analysis of analytes distributed in a 3-dimensional volume (e.g., 1 ~ 100 mm3) of various synthetic and biological matrices (e.g., chewing gum, leaves, fruits, roots, pork, lung tissues) without either mashing the sample or matrix separation. Using different extraction solvents, online chromatographic separation of chemicals inside the sample volume was observed during iEESI-MS analysis. The presented method is featured by the high speed of analysis, high sensitivity, low sample consumption and minimal sample preparation and/or degradation, offering unique possibilities for advanced applications in plant science, clinical diagnosis, catalyst studies, and materials science.

Tissue spray ionization mass spectrometry for rapid recognition of human lung squamous cell carcinoma

“…Chemical analysis by mass spectrometry (MS) may be an alternative to standard frozen-section histology, as mass spectrometry can provide rich molecular information on the chemicals on and in the tissue, which can be correlated with pathology 9 10 11 . Recently, MS analysis of tissue has advanced rapidly and a number of ionization methods have been used to characterize tissue sections without performing chemical extraction prior to analysis.…”

“…A large electrical potential was applied to create electrospray that contained small molecules extracted from the tissue sample. More recently, Graham Cooks and coworkers 10 performed MS analysis of animal tissue samples from biopsy needle. Electrospray ionization directly from the sample on the tip of biopsy needle was shown to provide abundant and highly specific molecular information via MS analysis.…”

Closing the Divide between Human Nutrition and Plant Breeding

“…A preliminary study measuring b-glucan content of malted barley (Hordeum vulgare L.) by single-kernel NIRS showed reasonable repeatability, and low correlations with enzymatic assays were attributed to the need for more variety-specific NIRS calibration curves due to variation in other kernel properties (de Sá and Palmer, 2006;Szczodrak et al, 1992). Finally, a new method for nondestructive analysis of living or synthetic tissue, known as internal extractive electrospray ionization mass spectrometry, has already been used for targeted metabolite analysis in the softer tissues of leaves, fruits, and roots (Zhang et al, 2013a), and could potentially be adapted to dried grain samples through use of a seed chipper or other device to expose the seed matrix. These single-kernel profiles had moderate to high heritabilities for most elements, even across six environments, permitting robust QTL detection in a maize recombinant inbred line population .…”

“…Digital image analysis is another rapidly evolving strategy for phenotyping of quality traits, with platforms currently in use for fruit color and color uniformity in tomato (Solanum lycopersicum L.) (Darrigues et al, 2008), grain density in barley (Walker et al, 2013), and panicle architecture traits that have implications for grain quality in rice (Crowell et al, 2014). Finally, a new method for nondestructive analysis of living or synthetic tissue, known as internal extractive electrospray ionization mass spectrometry, has already been used for targeted metabolite analysis in the softer tissues of leaves, fruits, and roots (Zhang et al, 2013a), and could potentially be adapted to dried grain samples through use of a seed chipper or other device to expose the seed matrix. Pairing this technique with NIRS or other methods measuring physical grain properties may be useful in understanding interactions between nutrient accumulation and other components of grain structure and composition, and notably would tend to uncover any correlated physical phenotypes as candidates for indirect selection within nutritional programs.…”

Direct Analysis and Quantification of Metaldehyde in Water using Reactive Paper Spray Mass Spectrometry

“…AI is a form of ionization that is performed on unmodified samples in open air and the method is capable of providing almost instantaneous data while minimizing sample preparation 22 23 24 25 26 27 28 29 . Some of the most popular AI techniques include desorption electrospray ionization (DESI) 30 , extractive electrospray ionization (EESI) 31 32 33 34 35 36 , desorption atmospheric pressure chemical ionization (DAPCI) 37 38 39 , and direct analysis in real time (DART) 40 41 . AI-MS shows promise as an analytical tool for in-situ applications and has been demonstrated in a variety of fields where timely intervention is highly desirable such as: homeland security 23 , food safety 42 , pharmaceutical drug development 43 , and environmental monitoring 44 .…”