Patent Document ID: 9128076
Application ID: 13641658
Patent Flag: 1

Claim One:
1. A method for microprobe analyses of isotope ratios in inhomogeneous matrices, comprising: selecting a plurality of matrix standards that have matrices that have a common characteristic with a sample matrix; running a bulk isotope analysis on each of the plurality of matrix standards to determine a bulk isotope ratio value for each of the plurality of matrix standards; running a plurality of microprobe analyses on each of the plurality of matrix standards to determine a plurality of microprobe isotope ratio values for each of the plurality of matrix standards; eliminating spurious values from the plurality of microprobe isotope ratio values; averaging the plurality of microprobe isotope ratio values for each of the plurality of matrix standards to create an average microprobe isotope ratio value associated with each of the plurality of matrix standards; plotting the bulk isotope ratio value for each of the plurality of matrix standards against the average microprobe isotope ratio value associated with each of the plurality of matrix standards to create a matrix corrected calibration curve; and running a microprobe analysis on a target region of the sample matrix and using the matrix corrected calibration curve to determine a matrix corrected isotope ratio, δ n M, for a selected element in the target region.