Femtosecond Laser Ablation ICP-MS Research Articles

Determination of Major and Trace Elements in Alloy Steels by Nanosecond and Femtosecond Laser Ablation ICP-MS with Non-matrix-matched Calibration

Determination of Major and Trace Elements in Alloy Steels by Nanosecond and Femtosecond Laser Ablation ICP-MS with Non-matrix-matched Calibration

Correlative Microscopy Techniques for the Analysis of Particles in Safeguards Environmental Samples

This paper presents a novel approach to environmental particle analysis for safeguards by means of a combination of micro-analytical techniques. It includes the tandem utilization of two separate light microscopes, a scanning electron microscope and a femtosecond laser-ablation ICP-MS. These are: a light microscopy automated particle relocation device (Zeiss Z2m); an optical-microscopy-based laser micro-dissection system (IX83 MMI+Olympus); a focussed ion beam scanning electron microscope equipped with a time-of-flight mass spectrometer extension (Tescan Lyra3) and a fs LA-ICP-MS (J200 from Applied Spectra Inc. and Thermofisher Scientific iCap Q). The samples examined in this contribution are analysed for their nuclear material signatures, in particular the presence of uranium isotopes.

Accurate determination of elements in silicate glass by nanosecond and femtosecond laser ablation ICP-MS at high spatial resolution

Despite the large number of successful applications of LA-ICP-MS, elemental fractionation remains the main limitation for many of its applications in the Earth sciences. This limitation is particularly notable for high spatial resolution analysis. Elemental fractionation and mass-load effect in silicate glasses NIST SRM 610 and GSE-1G were investigated by using 193nm ArF excimer nanosecond (ns) laser and 257nm femtosecond (fs) laser ablation systems coupled to inductively coupled plasma mass spectrometry. Contrary to those observed in ns-LA-ICP-MS, the most elemental fractionation at the small spot sizes of 16–24μm are lower than that at the large spot sizes of 44–60μm in fs-LA-ICP-MS. The significantly different fractionation behaviors of Li, Na, Si, K, V, Cr, Mn, Fe, Co, Ni, Cu, Rb, Cs and U between silicate glass materials NIST SRM 610 and GSE-1G observed in 193nm excimer LA-ICP-MS are eliminated by using 257nmfs-LA-ICP-MS at high spatial resolution. In addition, the mass load effect and matrix dependent mass load effect are also found to be reduced by using fs-LA-ICP-MS in comparison with ns-LA-ICP-MS. Except for Sb, Pb and Bi, the elemental fractionation is independent on the laser fluence chosen, which is irrespective of ns- or fs-LA-ICP-MS. In this study, a spot size of 24μm was used to test the capabilities of LA-ICP-MS analysis at high spatial resolution. The agreement between our data and the reference values is better than 10% for most of the elements in MPI-DING, USGS, and NIST glasses by using fs-LA-ICP-MS. For ns laser ablation analysis, the accuracy is highly dependent on the calibration strategies used (conventional external calibration method or 100% oxide normalization method) and the selected external reference materials (NIST SRM 610 or GSE-1G). The much less laser-induced elemental fractionation and matrix effect in fs-LA-ICP-MS in comparison with 193nm excimer LA-ICP-MS make it more suitable for the analysis of silicate materials at high spatial resolution.

Determination of 10 major and 34 trace elements in 34 GSJ geochemical reference samples using femtosecond laser ablation ICP-MS

Determination of 10 major and 34 trace elements in 34 GSJ geochemical reference samples using femtosecond laser ablation ICP-MS

Trace elements of Indium-bearing sphalerite from tin-polymetallic deposits in Bolivia, China and Japan: A femto-second LA-ICPMS study

Indium-bearing tin-polymetallic base metal deposits in Japan (Toyoha, Ashio and Akenobe), China (Dulong and Dachang), and Bolivia (Potosi, Huari Huari, Bolivar and Porco), were studied using femto-second Laser Ablation ICPMS (fsLA-ICPMS) and EPMA analyses for major and minor elements in sphalerite, paying special attention to In concentrations.Sphalerite is a principal mineral in these tin-polymetallic deposits and a broad range of In concentration is measured in the ores. There are distinct differences in mode of occurrence of the sphalerite and the distribution of In. The highest In concentration (up to 18wt.%) occur as a Zn–In mineral within black sphalerite zones in an oscillatory-zoned sphalerite from the Huari Huari deposits. Additionally, jamesonite from the Huari Huari deposit also contains anomalous In values, ranging from several hundreds to thousands μg/g. Sphalerite from the Toyoha and the other Bolivian deposits are characterized by oscillatory and chemical zoning, whereas those from Akenobe and the Chinese deposits are represented by homogeneous distribution of In. The 1000In/Zn values of sphalerite are in good agreement with those of the ore grade for each of the selected tin polymetallic deposits indicating that sphalerite is the principal host of In.The In-bearing sphalerite principally involves the combined coupled substitutions (2Zn2+)↔(Cu+, In3+), (3Zn2+)↔(Cu+, Ag+, Sn4+) and (3Zn2+)↔(2Cu+, Sn4+). The first of these is apparent in sphalerite from Huari Huari and Bolivar, whereas the second is prominent in sphalerite from Toyoha, Ashio, Potosi, Porco and Dachang. Akenobe and Dulong sphalerite features the dominant coupled substitution of (2Zn2+)↔(Cu+ or Ag+, In3+), owing to their poor Sn content. Occasionally, sub-micron inclusions of minerals such as stannite and Pb–Sb-bearing sulfides can occur in sphalerite, contributing to high Cu–Sn and high-Ag contents, respectively. The observed correlations of each element in the In–Cu–Ag–Sn-bearing sphalerite can be proposed as a fundamental reason for the indium enrichment related to sulfur-rich oxidized magmatism. In addition, the Ag content in sphalerite is considered a possible indicator of formation depth, which ranges from plutonic to subvolcanic environments.

Evaluation of different calibration strategies for the analysis of pure copper and zinc samples using femtosecond laser ablation ICP-MS

Solution-doped metal powder pellets as well as aspirated liquids were used as calibration samples to analyze pure copper and zinc certified reference materials (CRMs) by femtosecond laser ablation ICP-MS. It was demonstrated that calibration by copper pellets resulted in relative deviations up to 20%, whereas fs-LA-ICP-MS among copper-based CRMs led to inaccuracies in the same range unless nominal mass fractions were chosen to be <3 mg/kg. Calibration by zinc pellets generally provided better accuracy. Depending on the analyte considered, deviations below 10% were obtained even for mass fractions close to the limit of quantification. Our data, therefore, indicate solution-doped metal powder pellets to be suitable as calibration samples for fs-LA-ICP-MS of metals. Furthermore, the utilization of liquid standards for calibration was found to result in stronger deviations of up to 50% for both copper and zinc samples which, in addition, turned out to be dependent on the plasma conditions.

Femtosecond laser ablation ICP-MS

Femtosecond laser ablation was investigated for direct solid sample chemical analysis. The phonon relaxation time in a solid is of the order of 100 fs, which is the same as the laser pulse duration. For such excitation, there should be little time for the matrix to experience a “temperature” during the laser pulse. If the surface explodes before the photon energy is dissipated as heat in the lattice, the ablation process should produce stoichiometric vapor (elemental fractionation should be negligible). Based on this hypothesis, NIST glasses were ablated using 100 fs laser pulses at 800 nm, with subsequent elemental analysis using the ICP-MS. Pb and U intensities, and Pb/U ratios in the ICP, were measured during repetitively femtosecond-pulsed ablation. These data show that fluence (laser energy/spot area) has a significant influence on the amount of mass ablated and on the degree of fractionation. An optimal fluence was found at which the fractionation index approached unity; negligible fractionation. Infrared femtosecond laser ablation produced similar characteristics to UV nanosecond laser ablation.