Non-matrix-matched calibration in bulk multi-element laser ablation - Inductively coupled plasma - Mass spectrometry analysis of diverse materials.

Laser ablation inductively coupled plasma - mass spectrometry (LA-ICP-MS) is a frequently used microanalytical technique in elemental analysis of solid samples. In most instances the use of matrix-matched calibration standards is necessary for the accurate determination of elemental concentrations. However, the main drawback of this approach is the limited availability of certified reference materials.

Quantification anomalies in single pulse LA-ICP-MS analysis associated with laser fluence and beam size.

Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has undergone major improvements in recent years which have led to reduction of the analysis time, higher spatial resolution, and better sensitivity. However, quantification and accurate analysis remain one of the bottlenecks in LA-ICP-MS analysis and so far satisfactory calibration solutions are restricted to well-documented matrices and suitable internal standards. Additional uncertainties associated with laser fluence and beam size various ablation cells and interfaces make quantification even more challenging.

Toward a Flexible and Efficient TiO Photocatalyst Immobilized on a Titanium Foil.

Titanium foils of different thicknesses were anodized, and the photocatalytic activity of the resulting TiO nanotube (NT) layers was determined. All of the titanium foils were anodized simultaneously under identical experimental conditions to avoid the influence of the aging of the anodizing electrolyte and other anodization parameters, such as voltage, time, and temperature. To characterize the microstructures of the titanium foils, we used electron backscatter diffraction (EBSD), scanning electron microscopy (SEM), and stylus profilometry analyses.

New Insights into Antibacterial and Antifungal Properties, Cytotoxicity and Aquatic Ecotoxicity of Flame Retardant PA6/DOPO-Derivative Nanocomposite Textile Fibers.

The aim of this study was to evaluate the antibacterial and antifungal activity, cytotoxicity, leaching, and ecotoxicity of novel flame retardant polyamide 6 (PA6) textile fibers developed by our research group. The textile fibers were produced by the incorporation of flame-retardant bridged 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) derivative (PHED) in the PA6 matrix during the in situ polymerization process at concentrations equal to 10 and 15 wt% (PA6/10PHED and PA6/15PHED, respectively). Whilst the nanodispersed PHED provided highly efficient flame retardancy, its biological activity led to excellent antibacterial activity against and , as well as excellent antifungal activity against and .

Resolving the nanoparticles' structure-property relationships at the atomic level: a study of Pt-based electrocatalysts.

Achieving highly active and stable oxygen reduction reaction performance at low platinum-group-metal loadings remains one of the grand challenges in the proton-exchange membrane fuel cells community. Currently, state-of-the-art electrocatalysts are high-surface-area-carbon-supported nanoalloys of platinum with different transition metals (Cu, Ni, Fe, and Co). Despite years of focused research, the established structure-property relationships are not able to explain and predict the electrochemical performance and behavior of the real nanoparticulate systems.

Nanoparticle Analysis in Biomaterials Using Laser Ablation-Single Particle-Inductively Coupled Plasma Mass Spectrometry.

In the past decade, the development of single particle-inductively coupled plasma mass spectrometry (SP-ICPMS) has revolutionized the field of nanometallomics. Besides differentiation between dissolved and particulate metal signals, SP-ICPMS can quantify the nanoparticle (NP) number concentration and size. Because SP-ICPMS is limited to characterization of NPs in solution, we show how solid sampling by laser ablation (LA) adds spatial-resolution characteristics for localized NP analysis in biomaterials.

Perceptual Image Quality Metrics Concept in Continuous Scanning 2D Laser Ablation-Inductively Coupled Plasma Mass Spectrometry Bioimaging.

This work focuses on the structural similarity (SSIM) index as a tool for optimization of the perceived visual image quality obtainable by continuous scanning 2D LA-ICPMS bioimaging, but also other mass spec imaging techniques may benefit from this approach. This index quantifies the differences between a distorted image and a reference image based on parameters associated with luminance, contrast, and noise. Since reference images are not normally available, a protocol was developed to virtually apply distortion-related information introduced by the LA-ICPMS imaging system to a reference image of one's choice.

Imaging Artifacts in Continuous Scanning 2D LA-ICPMS Imaging Due to Nonsynchronization Issues.

Pulsed laser ablation (LA) devices in laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) imaging have become very advanced, delivering laser pulses with high temporal accuracy and stable energy density. However, unintentional imaging artifacts may be generated in 2D element maps when the LA repetition rate and the data acquisition parameters of ICPMS instruments with a sequential mass spectrometer (i.e.

Gelatin gels as multi-element calibration standards in LA-ICP-MS bioimaging: fabrication of homogeneous standards and microhomogeneity testing.

Highly homogeneous multi-element gelatin calibration standards were fabricated for quantitative LA-ICP-MS bioimaging. Heterogeneity issues caused by the so-called "coffee-stain" and/or "Marangoni" effects were found to be element-dependent but could be circumvented by careful selection of drying/setting conditions. A micro-homogeneity test was developed for certification of the standards.

Electrochemical Dissolution of Iridium and Iridium Oxide Particles in Acidic Media: Transmission Electron Microscopy, Electrochemical Flow Cell Coupled to Inductively Coupled Plasma Mass Spectrometry, and X-ray Absorption Spectroscopy Study.

Iridium-based particles, regarded as the most promising proton exchange membrane electrolyzer electrocatalysts, were investigated by transmission electron microscopy and by coupling of an electrochemical flow cell (EFC) with online inductively coupled plasma mass spectrometry. Additionally, studies using a thin-film rotating disc electrode, identical location transmission and scanning electron microscopy, as well as X-ray absorption spectroscopy have been performed. Extremely sensitive online time-and potential-resolved electrochemical dissolution profiles revealed that Ir particles dissolve well below oxygen evolution reaction (OER) potentials, presumably induced by Ir surface oxidation and reduction processes, also referred to as transient dissolution.

Importance of non-intrinsic platinum dissolution in Pt/C composite fuel cell catalysts.

The dissolution of different platinum-based nanoparticles deposited on a commercial high-surface area carbon (HSAC) support in thin catalyst films is investigated using a highly sensitive electrochemical flow cell (EFC) coupled to an inductively coupled plasma mass spectrometer (ICP-MS). The previously reported particle-size-dependent dissolution of Pt is confirmed on selected industrial samples with a mean Pt particle size ranging from 1 to 4.8 nm.

Metal maps of sclerotic hippocampi of patients with mesial temporal lobe epilepsy.

The loss of metal homeostasis has been implicated in the pathophysiology of mesial temporal lobe epilepsy associated with hippocampal sclerosis (mTLE-HS). Here we applied laser ablation inductively coupled plasma mass spectrometry imaging to establish the spatial distribution of Zn, Fe, Cu and Mn in coronal sections of hippocampi of four patients with drug-resistant mTLE-HS who underwent amygdalohippocampectomy. Detailed maps of the metal concentrations in the different morphological areas/layers were built and analyzed.

Novel Image Metrics for Retrieval of the Lateral Resolution in Line Scan-Based 2D LA-ICPMS Imaging via an Experimental-Modeling Approach.

The quality of elemental image maps obtained via line scan-based LA-ICPMS is a function of the temporal response of the entire system, governed by the design of the system and mapping and acquisition conditions used, next to the characteristics of the sample. To quantify image degradation, ablation targets with periodic gratings are required for the construction of a modulation transfer function (MTF) and subsequent determination of the lateral resolution as a function of image noise and contrast. Since such ablation targets, with suitable matrix composition, are not readily available, computer-generated periodic gratings were virtually ablated via a computational process based on a two-step discrete-time convolution procedure using empirical/experimental input data.

Multi-element analysis of wines by ICP-MS and ICP-OES and their classification according to geographical origin in Slovenia.

Inductively coupled plasma mass spectrometry and optical emission were used to determine the multi-element composition of 272 bottled Slovenian wines. To achieve geographical classification of the wines by their elemental composition, principal component analysis (PCA) and counter-propagation artificial neural networks (CPANN) have been used. From 49 elements measured, 19 were used to build the final classification models.

The effect of fluoride ions on the corrosion behaviour of Ti metal, and Ti6-Al-7Nb and Ti-6Al-4V alloys in artificial saliva.

Metallic materials used for manufacture of dental implants have to exhibit high corrosion resistance in order to prevent metal release from a dental implant. Oral cavity is aggressive towards metals as it represents a multivariate environment with wide range of conditions including broad range of temperatures, pH, presence of bacteria and effect of abrasion. An increasing use of various Ti-based materials for dental implants and orthodontic brackets poses the question of their corrosion resistance in the presence of fluoride ions which are present in toothpaste and mouth rinse.

The Effect of pH Value of a Simulated Physiological Solution on the Corrosion Resistance of Orthopaedic Alloys.

Metals and alloys used in orthopaedics and dentistry are exposed in vivo to various agents and environmental conditions. One of the important factors that determine the corrosion behaviour of metallic biomaterials is the pH of the environment. The corrosion resistance of stainless steel 316L (Fe/Cr18/Ni10/Mo3), titanium and titanium alloy Ti-6Al-4V (Ti90/Al6/V4) was studied in terms of their electrochemical properties and biodegradation in simulated physiological solutions of different pH values (4.

Quantitative multi-element mapping of ancient glass using a simple and robust LA-ICP-MS rastering procedure in combination with image analysis.

The surface of two glass artefacts in mosaic style, probably fragments of conglomerate glass bowls dating back two millennia, was investigated by laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS). By rastering with the laser beam over a selected area of the surface of the glass artefacts, elemental oxide maps were generated. Quantification of the elemental oxides in the maps was achieved using a so-called sum normalization procedure, summating the elements-54 in total-as their oxides to 100% (w/w), without using an internal standard and applying only one external standard (NIST SRM glass 610).

Basic modeling approach to optimize elemental imaging by laser ablation ICPMS.

The quality of element image maps generated by laser ablation (LA) ICPMS rastering depends on the measurement conditions (laser fluence, repetition rate, beam diameter, scanning speed, flow rate, and acquisition time). Optimizing these conditions is often a matter of trial and error since the quality criteria for elemental imaging (sensitivity, spatial resolution, noise, and analysis time) are intricately linked. A simple mathematical model, and ensuing software, was developed to simulate the LA-ICPMS output upon virtual rastering of a digital image of a cross-section of a sample.

Comparison of laser ablation-inductively coupled plasma-mass spectrometry and micro-X-ray fluorescence spectrometry for elemental imaging in Daphnia magna.

Visualization of elemental distributions in thin sections of biological tissue is gaining importance in many disciplines of biological and medical research. Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) and scanning micro-X-ray fluorescence spectrometry (micro-XRF) are two widely used microanalytical techniques for elemental mapping. This article compares the capabilities of the two techniques for imaging the distribution of selected elements in the model organism Daphnia magna in terms of detection power and spatial resolution.

Characterization of artificially generated PbS aerosols and their use within a respiratory bioaccessibility test.

A new method is presented for the preparation, characterization and use of PbS (galena) nanoparticles within an in vitro bioaccessibility test representing the respiratory tract, specifically the conditions occurring in conjunction with phagocytosis by cells using artificial lysosomal fluid. Particle production through nanosecond laser ablation enables their rapid production with a relatively narrow particle size distribution, and a diameter enabling them to represent particles that can enter the alveolar region of the respiratory tract (<3 microm). The PbS nanoparticles were characterized by cascade impaction to define their particle size distribution and through the use of X-ray diffraction (XRD) and electron microprobe analysis (EMPA) to define their mineralogy and homogeneity respectively.

Multi-element quantification of ancient/historic glasses by laser ablation inductively coupled plasma mass spectrometry using sum normalization calibration.

Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) for quantitative analysis of ancient/historic glasses is subject to calibration issues which have been addressed in this work. Since ancient/historic glasses have widely ranging matrix compositions, a complementary analysis by an alternative method is generally employed to determine at least one major element which can be used as an internal standard. We demonstrate that such a complementary analysis is unnecessary using a so-called sum normalization calibration technique (mathematically formulated) by simultaneous measurement of 54 elements and normalizing them to 100% [w/w] based on their corresponding oxide concentrations.

Chromium in soil layers and plants on closed landfill site after landfill leachate application.

Landfill leachate (LL) usually contains low concentrations of heavy metals due to the anaerobic conditions in the methanogenic landfill body after degradation of easily degradable organic matter and the neutral pH of LL, which prevents mobilization and leaching of metals. Low average concentrations of metals were also confirmed in our extensive study on the rehabilitation of an old landfill site with vegetative landfill cover and LL recirculation after its treatment in constructed wetland. The only exception was chromium (Cr).