Prof. Holcombe's group is involved in a variety of research areas focusing on trace metal analysis. The central theme is in the development of improved techniques (including new sources); speciation and preconcentration; and developing a better understanding of the processes preceding signal measurement.

Biomolecules and biopolymers for metal binding

We are attempting the first ever use of short chain biomolecules for trace metal preconcentration using flow injection systems with small columns containing these molecules chemically bonded to "controlled pore glass". It is the intent to take advantage of Mother Nature's concept of "metal binding proteins". We are using biopolymers to accomplish similar goals using theses more readily prepared materials. The advantages sought are selectivity and strong binding with the ability to denature (i.e., "unwrap") the molecule to easily release the metal -- on demand!

ETV-ICP-MS (electrothermal vaporization-inductively coupled-mass spectrometry)

ETV-ICP-MS is probably the most powerful elemental analytical tool in the field today. With sub-ppb and sub-ppt sensitivities and multielement capabilities, it has gained wide acceptance in spite of its $170-250K price tag. However, many applications have only a limited sample amount (microanalysis). An electrothermal vaporizer (ETV... sometimes referred to as a graphite furnace) used as a sample introduction provides a solution. One aspect of this research involves understanding the formation and transport to the ICP of the aerosol generated by the ETV. Additionally, we will exploit the transient nature of the ETV pulse and the more efficient transport (compared to conventional nebulizers) to improve sensitivity and sample throughput over what is currently available.