Software Solution for Post-Column Isotope Dilution Liquid Chromatography–Inductively Coupled Plasma Mass Spectrometry

Abstract

The application of isotope dilution in high performance liquid chromatography (HPLC) and inductively-coupled plasma mass spectrometry (ICP-MS) represents an important tool for elemental speciation analysis. Currently commercially available software deals only with one type of HPLC-ID-ICP-MS measurement comprising an addition of isotope-enriched species into the sample before HPLC separation, that is, species-specific isotope dilution. However, there is another possibility: species-unspecific isotope dilution, which is, unfortunately, not easily employed by common software. In this method, the isotope enriched solution containing common inorganic compound of the analyzed element is added to the sample after HPLC separation. Here a novel software system addresses this problem. The most important features of the computer program include easy operation, data adjustment by smoothing, detector dead-time correction, mass discrimination correction, background correction, integration of peak area and ID enumeration, processing of multi-elemental analyses, a choice of various isotopes, and a database of isotope abundances. The reliability of the software was demonstrated by processing of artificial chromatographic data and real chromatograms of standard reference materials containing mercury species and mixtures of selenium species.

Keywords:

• Isotope dilution
• Software
• Speciation analysis

Acknowledgments

Financial support from specific university research MSMT No 21/2012 – A1_FCHI_2012_003 and A2_FCHI_2012_002 is greatly acknowledged.

Notes

*It should be periodically recalibrated.

*Based on n = 3 independent determinations. Found values are expressed as mean±standard deviation.

*Based on n = 3 independent determinations. Found values are expressed as mean±standard deviation.

*Based on n = 12 individual determinations. Calculated values of slopes and intercepts are expressed together with confidence interval (Kleinbaum et al. 2007).