Analytical Chemistry

ICP-MS Analysis of Mercury in Fish: Exploration of Method Validation, Matrix Effect, and Kinetic Energy Discrimination

Authors

  • Wonhyeuk Jung Department of Chemistry and Biochemistry, University of California, Los Angeles ,
  • Christopher Dunham Department of Chemistry and Biochemistry, University of California, Los Angeles ,
  • Katie Perrotta Department of Chemistry and Biochemistry, University of California, Los Angeles ,
  • Yu Chen Molecular Instrumentation Center, University of California, Los Angeles ,
  • James Gimzewski California NanoSystems Institute, University of California, Los Angeles ,
  • Joseph Loo Department of Chemistry and Biochemistry, University of California, Los Angeles

Abstract

Inductively coupled plasma-mass spectrometry (ICP-MS) is a powerful analytical technique that can quantify elements of interest at parts-per-trillion concentrations. In this laboratory class, students performed ICP-MS analysis to quantify mercury concentration of standard reference material (SRM) 1947 (Lake Michigan fish tissue) and canned tuna from a local supermarket. These two samples were digested in two different matrices (HNO3/ H2O2 or HNO3/HCl/H2O2) and then analyzed using no-gas mode or helium mode with two different kinetic energy discrimination voltages (2V or 4V). The inclusion of HCl in the matrix produced more accurate results and stabilized mercury over the 8-day period after the digestion. Based on their analysis, the students were asked to draw their own conclusions about what they perceived to be the most accurate representation of the true mercury concentration of the tuna samples. This laboratory class provides students with a wide range of scientific concepts to explore such as method verification with SRM, kinetic energy discrimination, matrix effect, and trace metal stability over time.

Content

Thumbnail image of ICP-MS Analysis of Mercury in Fish.pdf

Supplementary material

Thumbnail image of Supporting Information 1 - Note for the instructors and students.docx
Supporting Information 1 - Note for the instructors and students
This supporting information provides more detailed instructions for the lab class. Key concepts for the instrument and the experiments, workflow, material preparation steps, and potential discussion questions for the students are provided.
Thumbnail image of Supporting Information 2 - Summary of raw data and surveys.docx
Supporting Information 2 - Summary of raw data and surveys
Raw data used to write the paper and the student survey results are provided in this supporting document.
Thumbnail image of Support Information 3 - Summary of Tune Reports.pdf
Support Information 3 - Summary of Tune Reports
The instrument parameters for acquiring the data are provided in this supporting document.