TITLE:
In Situ Analysis of Copper Alloys by Femtosecond Laser Ablation Inductively Coupled Plasma Mass Spectrometry: Constrains on Matrix Effects
AUTHORS:
Germán Velásquez, Anastassia Y. Borisova, Sandrine Baron, Luc Robbiola
KEYWORDS:
Copper Alloys, Reference Material, Matrix Effect, In-Situ Metal Determinations, Near-Infrared Femtosecond Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (NIR fs-LA-ICP-MS)
JOURNAL NAME:
American Journal of Analytical Chemistry,
Vol.9 No.3,
March
15,
2018
ABSTRACT: Direct analysis of copper-base alloys using laser ablation techniques is
an increasingly common procedure in cultural heritage studies. However, main discussions
remain focused on the possibility of using non-matrix matched external
reference materials. To evaluate the occurrence of matrix effects during in situ microanalysis of copper-base
materials, using near infrared femtosecond laser ablation techniques (NIR
fs-LA-ICP-MS), two bronzes, i.e.,
(Sn-Zn)-ternary and (Sn)-binary copper-matrix reference materials, as well as a
reference synthetic glass (NIST-SRM-610) have been analyzed. The results have
been compared to data obtained on a sulfide-matrix reference material. Similar
values in relative sensitivity averages of 63Cu, 118Sn
and 66Zn, as well as in 118Sn/63Cu and 66Zn/63Cu
ratios were obtained, for all analyzed matrix types, i.e., copper-base-, silicate-, and sulfide-reference materials.
Consequently, it is possible to determinate major and minor element
concentrations in copper alloys, i.e.,
Cu, Sn and Zn, using silicate and sulfide reference materials as external
calibrators, without any matrix effect and over a wide range of concentrations
(from wt.% to ppm). Equally, Cu, Sn and Zn concentrations can be precisely
determined in sulfides using homogeneous alloys (reference) materials as an
external calibrator. Thus, it is possible to determine Cu, Sn and Zn in copper-base
materials and their ore minerals, mostly sulfides, in a single analytical
session, without requiring specific external calibrators for each matrix type.
In contrast, immiscible elements in copper matrix, such as Pb and Fe show
notable differences in their relative sensitivity values and ratios for
different matrix-materials analyzed, implying that matrix-matched external
calibrations remain to be applied for their trace quantification.