SPLAT II

SPLAT II is a second-generation Single Particle Laser Ablation Time-of-Flight mass spectrometer. A high-precision and unique instrument, it allows users to study the fundamental processes that govern the chemistry and physics of particles on the nano- and micro-scales. SPLAT II's applications include but are not limited to climate, air pollution, human health, bioterrorism, and emerging nanotechnologies.

Portability is a hallmark of SPLAT II—it is the first field-deployable instrument that provides, in real time, the size, density, shape, fractal dimension, and composition of individual particles down to 50 nm in diameter. It is also the first instrument operated in the field in an IR-UV mode; this operation mode yields reproducible and quantitative particle mass spectra.

SPLAT II's high measurement rate permits rapid characterization of quickly changing samples, for example, fast chemical reactions, and its high sensitivity allows characterization of particles with low number concentrations. Its versatility allows characterization of any particle type, including volatile and non-volatile fractions of internally mixed aerosol particles commonly encountered in the atmosphere and engine exhaust. Its wide size range and low size limit are essential for characterizing nanoparticles, atmospheric aerosol, and engine emissions. In addition, its sizing precision allows researchers to follow physical and chemical transformation of the particles with submonolayer resolution. Under normal operating conditions millions of particles are detected and characterized, using dedicated data visualization software called SpectraMiner.

Instrument Description

SPLAT II uses an extremely efficient aerodynamic lens inlet to produce a narrow (250 μm) low divergent particle beam. Two stages of differential pumping separate particles and gas. Two stages of optical detection use light scattering to detect each particle twice and to measure its velocity, from which the particle aerodynamic diameter is obtained. Pulsed, synchronized IR evaporation followed by UV ionization of semi-volatile fractions and ablation of non-volatile fractions creates ions. From these ions, time-of-flight mass spectra are generated for compositional analysis.

The compact, portable, and aircraft-compatible SPLAT II is designed for bench and field use. It has been used to characterize the unique properties and behavior of nanoparticles in the laboratory and to characterize atmospheric particles and exhaust particulate emissions in the field.

SPLAT technique has been applied to aerosol studies in Houston, Texas; Cheju Island, South Korea; New York City; National Transportation Research Center, Oak Ridge, Tennessee; and Cummins Inc., Columbus, Indiana.

Spectraminer for High-throughput Data Analysis

SpectraMiner, a dedicated data mining and visualization software is specifically designed to explore single-particle mass spectra. It helps researchers make use of the vast amounts of detailed data generated by SPLAT II. SpectraMiner puts the scientist at the center of the data mining process, providing intuitive controls that connect the particle data with any other relevant events pushing the knowledge beyond simple statistical analysis.

SpectraMiner presents a multitude of views to the scientist.

SpectraMiner:

  • Organizes data in a hierarchical fashion
  • Provides an interactive and intuitive interface to explore the data
  • Makes viewing data easy at any level of detail
  • Searches for and displays relationships between different observables
  • Runs on a PC in real time driven by simple mouse clicks.
User Portal Name: Mass Spectrometer: Single Particle (SPLAT II)
Instrument ID:
34020
Availability: 10 hours a day, 5 days a week

Custodians

Publications

Airborne observations from four flights during the 2008 Indirect and Semi-Direct Aerosol Campaign (ISDAC) are used to examine some cloud-free optical...
Although the Euclidean distance does well in measuring data distances within high-dimensional clusters, it does poorly when it comes to gauging inter...
Climate research produces a wealth of multivariate data. These data often have a geospatial reference and so it is of interest to show them within...
Calculations were performed to determine the structures, energetics, and spectroscopy of the atmospherically relevant complexes (HNO₃)&...
Ambient particles and droplets have a significant effect on climate, visibility, and human health. Once formed, they undergo continuous...
The photooxidation of α-pinene in the presence of NO2, with and without added NaNO3 seed particles, has been studied in a large diameter...
Airborne fly ash from coal combustion may represent a source of bioavailable iron (Fe) in the open ocean. However, few studies have been made...
While multifunctional organic nitrates are formed during the atmospheric oxidation of volatile organic compounds, relatively little is known about...
Sources and chemical composition of the brown carbon are poorly understood, and even less is known about the mechanisms of its atmospheric...
For studying the formation and photochemical/thermal reactions of aerosols relevant to the troposphere, a unique, high-volume, slow-flow, stainless...
More stringent emissions regulations are continually being proposed to mitigate adverse human health and environmental impacts of internal combustion...
Particle density is an important and useful property that is difficult to measure because it usually 5 requires separate instruments to measure two...
Single particle mass spectrometers have traditionally been deployed to measure the size and composition of individual particles at relatively slow...
Aerosol indirect effect remains the most uncertain aspect of climate change modeling because proper test requires knowledge of individual particles...
Field measurements of secondary organic aerosol (SOA) find higher mass loads than predicted by models, sparking intense efforts to find additional...
Aircraft measurements during the Indirect and Semi-Direct Aerosol Campaign (ISDAC) in April 2008 are used to investigate aerosol indirect effects in...
Airborne particles play a critical role in air quality, human health effects, visibility and climate. Secondary organic aerosols (SOA) account for a...
Particle shape is an important attribute that is very difficult to characterize. We present a new portable system that offers, for the first time,...
Substantial uncertainties still exist in the scientific understanding of the possible interactions between urban and natural (biogenic) emissions in...
Formation, properties, transformations, and temporal evolution of secondary organic aerosols (SOA) particles strongly depend on particle phase....
This manuscript presents an overview of the most recent instrument developments, field and laboratory applications of mass spectrometry (MS) in...
Secondary organic aerosols (SOA) formed in the atmosphere from the condensation of semivolatile oxidation products are a significant component of...
Electrically conductive silicone tubing is used to minimize losses in sampling lines during the analysis of airborne particle size distributions and...
The gas-phase reactions of nitrate radicals (NO3) with biogenic organic compounds are a major sink for these organics during night-time. These...
We describe a system designed to measure the size, composition and density of individual particles in real-time. It uses a DMA to select a...
With the advert of aerosol instrumentation it has become possible to simultaneously measure individual particle mobility and vacuum aerodynamic...
Single Particle Mass Spectrometers are sophisticated instruments designed to measure the sizes and compositions of a wide range of individual...
The extremely high particle transmission efficiency of aerodynamic lens inlets resulted in their wide use in aerosol mass spectrometers. One of the...
A large fraction of atmospheric particles are composed of hygroscopic salts that are mixed with variety of organic molecules, of which surfactants...
Semi-empirical secondary organic aerosol (SOA) models typically assume a well-mixed organic aerosol phase even in the presence of hydrophobic primary...
A significant fraction of atmospheric particles are composed of inorganic substances that are mixed or coated with organics. The behavior of these...
To take full advantage of the vast amount of highly detailed data acquired by single particle mass spectrometers requires that the data be organized...
Particle volumes are most often obtained by measuring particle mobility size distributions and assuming that the particles are spherical. These...
The properties of aerosols depend on the size and internal compositions of the individual particles. The vast majority of atmospheric aerosols are...
Diesel offers higher fuel efficiency, but produces higher exhaust particulate matter. Diesel particulate filters are presently the most efficient...
Results are presented from an intercomparison of single-column and cloud resolving model simulations of a deep, multi-layered, mixed-phase cloud...
Recent improvements in single particle mass spectrometers make it possible to optically detect, size, and characterize the compositions of individual...
One of the most fundamental aspects of single particle mass spectrometry is that the individual particle mass spectra are first classified and only...

Quick Specs

    • Simultaneous Measurements
    • Yields quantitative information about all particle types
    • Detects particles from 50 nm to 3 μm in size
    • Measures up to 50 particles/second

Science Highlights

Posted: Sunday, March 31, 2013 - 17:00
Working at EMSL, scientists from Pacific Northwest National Laboratory, University of Washington and Imre Consulting used a new approach to measure...
Posted: Wednesday, November 14, 2012 - 16:00
Researchers working at EMSL found airborne particles formed around pollutants can last longer than previously thought and travel great distances,...
Posted: Monday, September 3, 2012 - 17:00
City carbons and country carbons regularly mix in the atmosphere, but how do they get along? That is essentially the question being tackled by a...
Posted: Wednesday, February 29, 2012 - 16:00
Airborne particles impact human health, cause haze, and influence climate. New findings reported by an EMSL user team in the Proceedings of the...
Posted: Tuesday, February 1, 2011 - 00:27
A long, frustrating search for the source of "extra" aerosols seen in field experiments but not in models might have come to an end when scientists...