In situ iron isotope ratio determination using UV-femtosecond laser ablation with application to hydrothermal ore formation processes

Micro-scale tracing of Fe and Si isotope signatures in banded iron formation using femtosecond laser ablation

“…Previous investigations have shown that the overall reproducibility of different types of matrixes including iron oxides and iron carbonates is better than ± 0.1‰ (2 SD) for  56 Fe and that the results are consistent with those obtained by conventional solution ICP-MS measurements (Horn et al, 2006). Over the course of 9 months, replicated spot analyses of the metal standard Puratronic (Johnson Matthey) resulted in mean values of 0.08‰ for  56 Fe and 0.12‰ for  57 Fe relative to IRMM-014, with an external precision of ± 0.08 and ± 0.14‰, respectively (2 SD, n=101) (Fig.…”

“…The Fe isotope composition of magnetite, siderite and ankerite were determined following the analytical procedure of Horn et al (2006). Previous investigations have shown that the overall reproducibility of different types of matrixes including iron oxides and iron carbonates is better than ± 0.1‰ (2 SD) for  56 Fe and that the results are consistent with those obtained by conventional solution ICP-MS measurements (Horn et al, 2006).…”

“…The laser ablation system is based on an amplified frequency-quadrupled femtosecond laser (Spectra Physics Hurricane I, USA) operating at a wavelength of 196 nm which avoids laser-induced isotope and elemental fractionation and minimizes the matrix dependency of analyses (Horn and von Blanckenburg, 2007). The accuracy and precision for Fe and Si isotope measurements have been verified for different types of matrices by Horn et al (2006) and Chmeleff et al (2008), respectively. Fe isotope ratios were determined by spot analysis with a diameter of 18 to 35 µm.…”

Evaluation of UV-fs-LA-MC-ICP-MS for Precise in situ Copper Isotopic Microanalysis of Cubanite

“…The use of femtosecond ablation drastically reduces or eliminates thermal-induced isotope fractionation that may occur during the laser ablation of metal, sulfide and oxide minerals using conventional nanosecond (ns) pulsed laser ablation systems, and thus improving the analytical precision and accuracy of iron and copper isotopes compared to nanosecond laser ablation. 16,17 Horn et al 16 reported that ultraviolet (UV)-fs-LA-MC-ICP-MS analyses did not require matrix-matched standards to obtain reliable iron isotope ratios of many iron-rich materials. In contrast, matrix-matched standards were still required for reliable in situ copper isotope analyses of copper-iron sulfide minerals (chalcocite and chalcopyrite) by using near-infrared (NIR)-fs-LA-MC-ICP-MS. 17 Although large well-crystallized cubanite is extremely rare, recently several natural crystals of cubanite appropriate for standards of laser analysis were obtained.…”

Development of an On-line Low Gas Pressure Cell for Laser Ablation-ICP-Mass Spectrometry

“…The release of large-size particles can be a main source of signal spikes obtained in the ICP-MS. 23 A new approach to minimize the production of large-size particles is the application of femto-second (fs) lasers. [31][32][33][34] Particle size-related elemental fractionation can be significantly An on-line low gas pressure cell device has been developed for elemental analysis using laser ablation-ICP-mass spectrometry (LA-ICPMS). Ambient gas in the sample cell was evacuated by a constant-flow diaphragm pump, and the pressure of the sample cell was controlled by changing the flow rate of He-inlet gas.…”