Quantification method for elemental bio-imaging by LA-ICP-MS using metal spiked PMMA films

Abstract

A method for quantitative analysis of biological soft tissues by laser ablation-inductively coupled plasma-mass spectrometry has been developed. Polymer film standards were produced by spin coating spiked solutions of poly methyl methacrylate onto quartz substrates. Calibration curves throughout the range of 0-400"llg g-l yielded correlation coefficients better than 0.999 for 66Zn and 63CU. Spiked, homogenised soft tissue standards were quantified by LA-ICP-MS against the thin film standards. The results agreed with values calculated from solution nebulisation rCP-MS. A procedure for internal standardisation by employing ruthenium or yttrium in the underlying thin film was also assessed.

A calibration strategy for LA-ICP-MS using isotope dilution for solid reference materials

“…25 The results differ in the accuracy of quantication depending on the calibration method used. In most cases, accuracies between 10 and 20% were obtained which are typical for most quantication procedures in solid state spectroscopy.…”

“…A disadvantage of this method is the timeconsuming and complex preparation of calibration standards at several different concentration levels. 25 The preparation of matrix-matched standards is also very time consuming and complex [26][27][28][29][30] and must be especially adaptable to biological samples. In addition to these problems the homogeneity of matrix-matched standards is oen insufficient, which decreases the accuracy.…”

“…However, most biological samples do not full this criterion appropriately. To overcome this problem the simultaneous ablation of a sample thin section and a polymeric thin lm of a homogeneously distributed element 25 could be used, where the polymer material serves as the correction standard for the normalization. A disadvantage of this method is the timeconsuming and complex preparation of calibration standards at several different concentration levels.…”

“…Thus, for the calibration of trace metal concentrations in biomaterials by LA-ICP-MS, different calibration strategies are published, for example, internal standardization, 17 external calibration, 18,19 matrix matched standards, 20,21 solution based isotope dilution [22][23][24][25] (ID) and lm coating. 25 The results differ in the accuracy of quantication depending on the calibration method used.…”

Laser ablation ICP-MS for quantitative biomedical applications

“…A new approach to elemental bioimaging by LA-ICP-MS that uses thin polymeric films spiked with elemental standards of the analytes and well selected ICP-MS internal standards (Ru and Y) as calibration standards has been recently proposed [34]. The tissue sample can be placed on top of a thin film containing an adequate IS.…”