iQuant2: Software for Rapid and Quantitative Imaging Using Laser Ablation-ICP Mass Spectrometry

Abstract

We report on the development of a software program named iQuant2 which creates visual images from two-dimensional signal intensity data obtained by a laser ablation-ICP-mass spectrometry (LA-ICPMS) technique. Time-resolved signal intensity profiles can be converted to position resolved signal intensity data based on the rastering rate (μm s−1) of the laser ablation. Background signal intensities obtained without laser ablation (gas blank) are used as the background, and all of the blank-subtracted intensity data can be used for the imaging analysis. With this software, deformation of the created image can be corrected visually on a PC screen. The line profile analysis between the user-selected points can be observed using the iQuant2 software. To accomplish this, data points on the profile line were automatically calculated based on the interpolation between the analysis points. The resulting imaging data can be exported and stored as JPEG, BMP or PNG formats for further processing. Moreover, a semi-quantitative analysis can be made based on the coupling of the external correction of the RSF (relative sensitivity factor) using NIST SRM610 with normalization of the corrected signal intensity data being 100%. The calculated abundance data for major elements are in reasonable agreement with the values obtained by electron probe micro analyzer (EPMA). With the software developed in this study, both the rapid imaging and semi-quantitative determinations can be made.

Bioimaging of multiple elements by high‐resolution LA‐ICP‐MS reveals altered distribution of mineral elements in the nodes of rice mutants

“…All elemental signals were obtained with an Agilent Technologies 8900 ICP‐MS device operated in helium mode. Time course ICP‐MS output of the raster scanning was converted to element image using iquant2 software (Suzuki et al ., ). At least two biological replicates of each sample were analyzed, which showed similar results.…”

“…In this technique, elements in a small spot of solid samples are ablated by focused laser beam in inert gas (He or Ar) atmosphere under normal pressure, and the laser‐induced aerosol is transferred with the carrier gas (He or Ar) into ICP‐MS directly (Wu and Becker, ; Zhao et al ., ). After raster scanning of the laser ablation, time‐resolved signal intensity profiles can be converted to two‐dimensional elemental mapping images by a computer program (Suzuki et al ., ). Therefore, this technique can provide both quantitative data and spatially revolved imaging of multiple elements.…”

Cell tracking of chromium‐labeled mesenchymal stem cells using laser ablation inductively coupled plasma imaging mass spectrometry

“…The signal intensity profile of the laser raster was measured in time‐resolved mode. Time‐resolved data acquired by ICP‐MS was visualized using iQuant 2+ software . To obtain the optimum contrast image of 52 Cr, the lower to upper limit range was set to the value of 500–2500 counts per second (cps), 100 to 25,000 cps and 2000 to 15,000 cps for cell‐suspension samples, thigh muscle sections and the half body section sample, respectively.…”

Quantitative Bio-imaging of Gadolinium-157 in Tissues Through Laser-ablation ICP-MS for Neutron Capture Therapy

“…The sections were inserted into a cell and ablated line by line using a commercial laser ablation instrument, an NWR213 (ESI New Wave Research, Oregon, USA), coupled to an Agilent 8800 Triple Quad ICP mass spectrometer (Agilent Technologies, Australia). The distribution of 157 Gd and 63 Cu were visualized using with the iQuant2 software 23) . Additionally, 157 Gd concentrations in the digested liver samples were measured using the conventional ICP-MS method as previously reported 24)- 33) .…”