X-rays Provide Higher Energy Resolution
X-ray spectroscopy is widely used to determine the elemental and chemical composition of materials. However, Lawrence Livermore National Laboratory and
STAR Cryoelectronics LLC’s Superconducting Tunnel Junction (STJ) X-ray
Spectrometer offers more than 10 times higher energy resolution than current
x-ray spectrometers based on silicon or germanium semiconductors. This higher
resolution is made possible through the use of a superconducting sensor that
excites 1,000 times more free charges than is possible in a semiconductor-based
sensor. This allows for the clear separation of characteristic x-ray lines, even at
low energies and in complicated multi-element samples. The team’s
development of an automated liquid-cryogen-free cryostat allows for
operation of the instrument at the required temperature of 0.3
K, and they solved acquisition time limitations by using up
to 112 sensors on a single array. The improved precision of
the STJ x-ray spectrometer over current technology, along
with its ease of operation, will make high-accuracy x-ray
fingerprinting available to non-expert users.
◗ Lawrence Livermore National Laboratory, www.llnl.gov
Greater Peak Detection
for HPLC
HPLC and UHPLC are ubiquitous laboratory tools
with enormous libraries of established separation
methods for a vast array of compounds, deployed
in diverse fields. The concern and challenge for
any analyst considering a new technology for their
application involves the effort required to adapt,
transfer or recreate an already established method
in a way that preserves the utility of the original
method. Excellims Corp.’s IA3100 integrated, compact high-performance ion mobility spectrometry
(HPIMS) detector for high-performance liquid
chromatography (HPLC) systems provides complete separation and detection of complex mixtures,
particularly when adding the IA3100 capabilities
to existent LC hardware, and can complement or
serve as a replacement for an end user’s present LC
detector.
The core technology of the IA3100 uses
advanced HPIMS to separate ions introduced via
electrospray ionization from the corresponding
HPLC eluent. HPIMS demonstrates higher performance over conventional IMS by offering ion
mobility base separation having resolving power
comparable to HPLC. Capitalizing on Excellims’
patented instrument design, the most important
technology advancement is the HPIMS which
achieves 60 to 120 resolving power, comparable to
the HPLC/UHPLC method coupled to it and two to
10 times better than conventional IMS, maintaining
the fidelity of the original chromatographic separation. The HPIMS separation also occurs in just
milliseconds with total acquisition times of seconds
per sample, so the detection is only limited by the
elution time from the HPLC or UHPLC.
◗ Excellims Corp., www.excellims.com
A Wide Angle on Chemical Sensing
Detection and measurement of trace gases at low concentrations, in the presence of dynamically changing
contaminants and at significant standoff distances, has important applications in both the civil and defense
spaces. The detection and localization of gas releases, such as methane from leaking natural gas pipelines or
nitrogen oxides from falling electrical equipment, requires high sensitivity to the target gas and insensitivity
to other atmospheric contaminants, and, ideally, can be performed at long ranges. MIT Lincoln Laboratory’s Wide-Area Chemical Sensor (WACS) system uses a tuned, broadband laser coupled to a lossless, spectrally discriminating receiver to detect gases at sensitivities as good as typical local detectors, at ranges up to
tens of kilometers, while compensating for atmospheric contaminants and instrument drift.
WACS’s enabling technology, a single lossless optical resonant cavity (Fabry-Perot etalon), spectrally
separates light that sees the gas of interest from light that doesn’t by tuning the cavity to coincide with
the gas absorption. All light encountering the cavity transmits through it or reflects off of it; comparison of these two light intensities allows measurement of the gas-induced absorption, which varies over
the bandwidth of the optical cavity’s spectral response for time-varying, but spectrally constant, losses
caused by atmospheric scintillation and other atmospheric contaminants.
◗ MIT Lincoln Laboratory, www.ll.mit.edu
Regenerating Suppressor Design
Suppressors, first invented in 1975 by Hamish Small, are used in ion chromatography (IC) to convert the eluent to a weakly dissociated form so the
analyte ions can be detected with high sensitivity. Early suppressors were,
from a regeneration perspective, batch mode devices that subsequently
evolved to a continuous mode device that was regenerated with chemical
reagents. Today, electrolytic regeneration is the preferred means of providing regenerated ions. The technology uses the electrolysis reaction to
generate the ions required for suppression. Further, the use of suppressed
eluent for providing the water required for electrolysis resulted in significant ease of use.
Thermo Fisher Scientific’s Thermo Scientific Dionex ERS 500 Electrolytically Regenerated
Suppressor is a significant leap in electrolytic suppressor product design. The Dionex ERS 500 is the first
fully regenerated high-capacity membrane suppressor that eliminates traditional gaskets and the need for
frequent off-line regeneration. The new design, comprising two ion exchange membranes and two flanking
regenerate channels, allows for operation at high pressures not feasible with current suppressors. The device
has a unique fluid channel design that preserves column efficiency and is compatible with 4-µm particle IC
columns for fast and high-resolution separations.
◗ Thermo Fisher Scientific, www.thermoscientific.com