# Research Activity: Separations and Analysis

Division: Chemical Sciences, Geosciences, and Biosciences

Primary Contact: William S. Millman (william.millman@science.doe.gov;
301-903-5805)

Team Leader: John C. Miller

Division Director: Eric Rohlfing (Acting)

# Portfolio Description:

This activity addresses the scientific principles that underlie
energy-relevant chemical separations and analytical methods,
capitalizing on the relationships between these two areas of chemistry
and Heavy Element Chemistry. It is focused around four main thrust areas
along with a small assortment of other science themes. The thrust areas
are:

-   Laser based techniques: These rely on laser based spectroscopies and
    other techniques that provide the basis for analytical methods.
    Besides spectroscopy, lasers are used as probes or the initiator of
    a process that is ultimately quantified.

-   Nanoscale science approaches to separations and analysis: These
    projects focus on aspects of the nanoscale that can be exploited to
    affect a separation or to understand the influence of the nanoscale
    on separations. These include nanoscale transport, synthesis of
    nanoscopic pores and structures, analysis of nanoscopic materials
    and relationship between nanoscale properties and chemical
    properties unique to the nanoscale.

-   Ionization processes in analysis: This thrust is the major focus of
    mass spectrometry programs. It includes surface preparation and
    modification associated with mass analysis, and the interactions
    between ions and molecules and the transport and acceleration of
    ions in a vacuum and in the presence of various applied fields.

-   Metal-adduct complexes for separations: This thrust is largely
    associated with extraction of trans-actinide elements. It includes
    the synthesis of ligands uniquely capable of interacting with
    specific elements. It also includes supramolecular complexes and
    other large structures such as micelles that can uniquely interact
    with transuranics along with their ability to attach or otherwise
    interact with surfaces and the resulting impact on selectivity.

The remaining activities are composed of a variety of projects such as
those related to analysis of catalysts and catalytic phenomena, NMR
analysis, droplet formation, solvation, a variety of synchrotron based
analyses, and a growing new area in chemical imaging.

Unique Aspects:

This activity represents the nation's most significant long-term
investment in solvent extraction, ion exchange, and mass spectrometry.
The supported research is characterized by a unique emphasis on
underlying chemical and physical principles, as opposed to the
development of methods and processes for specific applications.

The portfolio for separations science emphasizes, but is not limited to,
the separations of radionuclides and other metal ions, and seeks
molecular-level understanding to support advances in both large-scale
and analytical-scale separations. Molecular-level understanding is also
sought for separations methods that have the potential to significantly
impact energy use, such as membrane-based processes. Ionic liquids and
supercritical fluid solvents are being explored with potential benefit
to "green chemistry." The use and impact of nanoscale and supramolecular
structures on various separations processes are of growing interest.

The analytical research portfolio has historically emphasized mass
spectrometry and seeks to elucidate the chemical and physical principles
that underlie ionization and excitation processes and modern approaches
to mass discrimination. A more recent sector of the portfolio seeks to
understand and use the interaction of electromagnetic radiation with
matter in phenomena such as molecular fluorescence, laser ablation and
surface-enhanced Raman scattering. Hyphenated laser-mass spectrometry
techniques such as MALDI-MS, laser ablation ICP-MS, and laser ionization
ion mobility-MS are being explored. The extension of these
ultrasensitive techniques to single-molecule detection and observation
is being explored. Research to understand chromatography at the
molecular level reflects the synergy between separations and analytical
sciences. This activity also contributes to the maintenance of the
scientific infrastructure required to meet as-yet-undefined challenges
in separations and analysis.

# Relationship to Other Programs:

The activity is closely coupled to the Department of Energy (DOE)
stewardship responsibility for actinide and fission product chemistry
and to its clean-up mission. The activity emphasizes the separations and
analysis of actinide and fission product elements and their decay
products. Some overlap and coordination with the BES Heavy Element
Chemistry Program is natural. Similarly, elements of the analysis
science portfolio benefit from cooperation with the BES Catalysis and
Chemical Transformations, Chemical Physics, Materials Chemistry, and
Atomic and Molecular Science Programs. The basic nature of the research
has led to advances in technologies ranging from those that support
nuclear non-proliferation efforts, to efforts in the President's
Hydrogen Fuel Initiative, and to aspects of the Human Genome Project.

# Significant Accomplishments:

This activity is responsible for such notable contributions as the
concept of host-guest complexation, for which Professor Donald Cram
(University of California, Los Angeles) shared the 1987 Nobel Prize in
Chemistry; the use of the inductively coupled plasma (ICP) for emission
and mass spectrometry; the development of the TRUEX process based on the
ligand design work of Dr. Phillip Horowitz; Dave Dahl's development of
SIMION, a program to [sim]{.underline}ulate the motion of
[ion]{.underline}s in fields that has become the standard tool
internationally for development of ion lens; and, more recently, the
development of BOB, a calixerene ligand that complexes Cs+ which is
based on design and development work of Bruce Moyer at Oak Ridge
National Laboratory (ORNL) and is being used to clean up waste tanks at
Savannah River National Laboratory (SRNL).

# Mission Relevance:

The success of the Manhattan Project was, in large part, due to our
ability to develop industrial-scale processes for separating plutonium
from irradiated fuel. Thus began the intense interest of DOE and its
predecessor agencies in the science that underlies separations
processes. The missions of DOE have evolved, and it must now face the
legacy of accumulated wastes from the cold war era. Knowledge of
molecular-level processes is required to characterize and treat these
extremely complex mixtures and to understand and predict the fate of
associated contaminants in the environment. In addition, separations
science and technology have huge economic and energy impacts. For
example, distillation processes in the petroleum, chemical, and natural
gas industries annually consume the equivalent of 315 million barrels of
oil (\~5.4% of total petroleum consumption). It is further estimated
that separations processes account for more than 5% of total national
energy consumption. Separations are essential to nearly all operations
in the processing industries and are necessary for many analytical
procedures.

Likewise, DOE and its predecessors were also driven to develop
analytical methodologies to support their early missions. Nuclear and
radiochemical analyses were supported and refined by developments in
analytical separations, such as solvent extraction and ion exchange. A
need for reliable potentiometric titration prompted the first use of
operational amplifiers in analytical chemistry and led to a revolution
in electrochemistry. Mass separations was required for assay in the form
of mass spectrometry and, in the form of the calutron, served as the
first method for the production of macroscopic quantities of separated
isotopes of uranium and other elements. As with separations science,
improved understanding of the underlying science is required to meet the
analytical challenges presented by the legacy of the Cold War and the
future challenges of DOE as its missions and responsibilities continue
to evolve.

# Scientific Challenges:

Challenges in separations science include the development of a deeper
understanding of processes driven by small energy differences. These
include self-assembly and molecular recognition, crystallization,
dispersion, coalescence, and hysteresis in transport properties of
glassy polymer membranes. The development of fundamental principles to
guide ligand design for atomic and isotopic specific recognition and
separations is also required. These, in turn, pose challenges to
analysts to generate the understanding required to characterize
amorphous materials through analysis of scattering data or other
methods. Other analytical challenges include single-molecule detection
and direct observation of bimolecular interactions and reactions. A
deeper understanding of laser-material interactions as well as
ionization and excitation sources for optical and mass spectrometric
analyses is also required. Significant challenges are posed by
elucidation of principles to underlie diagnostics at interfaces between
synthetic materials and biomolecules, at oxide-aqueous interfaces, and
to monitor spatial and temporal processes in, and on the surfaces of
living cells. Though understanding at the molecular level is required,
there is currently insufficient knowledge to extend that understanding
from the molecular level to the nanoscale, to mesoscale, and finally, to
macroscale phenomena. Pursuit of that knowledge presents a major
challenge to this activity.

**Funding Summary:**

Dollars in Thousands

[FY 2005]{.underline} [FY 2006]{.underline} [FY 2007]{.underline}
[Request]{.underline}

15,490 17,287 24,041

[Performer]{.underline} [Funding Percentage]{.underline}
[(2005)]{.underline}

DOE Laboratories 56%

Universities 44%

These are percentages of the operating research expenditures in this
area; they do not contain laboratory capital equipment, infrastructure,
or other non-operating components.

This activity provides funding for about 50 university grants
supporting, at any given time, on the order of 60-70 graduate students
and 25-30 postdoctoral associates. In addition, 14 programs at DOE
national laboratories support numerous senior staff, and additional
students and postdoctoral associates. Programs at the national
laboratories are typically multi-investigator efforts on problems that
require extensive collaboration by senior scientists and postdoctoral
associates. These programs act as the focal point for specific research
efforts vital to the DOE mission. This activity supports research
programs at ORNL, Argonne National Laboratory (ANL), and Pacific
Northwest National Laboratory (PNNL), with smaller efforts at Ames
Laboratory, and Lawrence Berkeley National Laboratory (LBNL). Many of
the research efforts at the national laboratories involve collaborations
with the university and industrial communities.

**Projected Evolution:**

Separations research will continue to advance the understanding of
multifunction separations media; supramolecular recognition (using
designed, multi-molecule assemblies to attract specific target species);
synthesis of new porous materials and control of interface properties at
the nanoscale; ligand design and synthesis of extractant molecules;
mechanisms of transport and fouling in polymer and inorganic membranes;
solvation in supercritical fluids; field-enhanced mixing; and drop
formation.

Analytical research will pursue the elucidation of ionization and
excitation mechanisms for optical and mass spectrometry; single molecule
detection, characterization, and observation; nano- and molecular-scale
analytical methods; laser-based methods for high-resolution spectroscopy
and for presentation of samples for mass spectrometry; characterization
of interfacial phenomena, with emphasis on chromatography;
surface-enhanced Raman spectroscopy; and use of quadrupole ion traps to
study gas-phase ion chemistry.

An expanded activity would support work to understand the underlying
science needed to image molecular assemblies and molecules in space and
time to enable new advances in science. The program is now in a position
to begin doing experiments similar to those in microscopy that brought
about a revolution our understanding of cells as the underlying
structure that supports life.