SRM 2061, 2062,
Ti Alloy,
Al-Nb-W
Ryna Marinenko
Surface and Microanalysis Science
Division
SRM 2703, Sediment for Solid Sampling Analytical Technique
Rolf Zeisler
Analytical Chemistry Division
SRM 2737, 2738, Nitric Oxide in Nitrogen
William Thorn
Analytical Chemistry Division
NIST RM 8785 Air Particulate
Matter on Filter Media
NIST RM 8786 Filter Blank
George Klouda
Surface and Microanalysis Science Division
James Filliben, ITL
 
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A TiAl(NbW) alloy was recently issued as two new NIST SRMs. They were developed for
the aerospace industry for use in microanalysis (SRM 2061) and x-ray fluorescence (XRF)
spectrometry (SRM 2062).
The material was tested for micro-heterogeneity and macro-heterogeneity with wavelength
dispersive spectrometer - electron probe microanalysis (WDS-EPMA) and WDS-XRF. The
overall relative expanded uncertainties for heterogeneity including the experimental
uncertainty was 1.1 % for Al and 0.92 % for Ti, 3.0 % for Nb, and 8.8 % for W. The bulk
material was analyzed with inductively coupled plasma-optical emission spectroscopy
(ICP-OES) and WDS-XRF. The NIST certified values for the elements in % mass fraction
with expanded.
Standard Reference Material (SRM) 2061
Standard Reference Material (SRM) 2062
March 2006
The analysis of solid materials by introducing solid test samples directly into the graphite furnace or
the plasma of an atomic absorption, emission, or mass spectrometer must be regarded as a powerful
analytical approach. After three decades of development, the instrumentation and the methodology are
available to apply solid sampling successfully for the
analysis of almost every material in the form of about
0.1 mg to 1 mg solid test portions. A significant
problem in the use of these emerging solid sample
techniques is a general lack in suitable certified
reference materials for calibration and quality assurance
purposes. No Standard Reference Materials® (SRMs)
have been certified for the small sample sizes typically
used for these techniques. Direct utilization of most
existing SRMs in solid sampling analysis procedures is
often unreliable because trace components may not be
sufficiently homogeneously distributed in the sample,
and their homogeneous distribution has not been
validated for sample sizes below 100 to
250 mg.
NIST homogeneous distribution has not been validated for sample sizes below 100 to 250 mg.
NIST has now developed the highly homogeneous SRM 2703. The certification of SRM 2703
included ten expert laboratories with active research programs in solid sampling techniques. In
combination with the analytical capabilities at NIST, including the extensive characterization
of the parent material SRM 2702, it was possible to provide certified and reference mass
fractions for 29 elements for a sample size of 0.7 mg. This product was then tested by INAA
for acceptance, and subsequently during the certification campaign further characterized for its
small sample homogeneity by micro-XRF, micro-PIXE, and laser ablation ICP-MS. These
techniques confirmed reproducibility of results at microgram sample sizes.
This material forms a new benchmark for homogeneity in a natural matrix SRM. It will help
to fill a critical gap in the availability of SRMs to the growing use of solid sampling
techniques in industrial, environmental, clinical, and other applications.
Standard Reference Material (SRM) 2703
March 2006
Nitric oxide (NO) is an important gaseous pollutant in ambient air because it spontaneously
oxidizes to form nitrogen dioxide (NO2) and nitric acid (HNO3) which are components of smog
and acid rain. NO is produced during combustion processes such as the burning of gasoline in
automobiles and the burning of fuel oils and natural gas to generate electric power.
The new SRMs were requested by the American Industry/Government Emissions Research
(AIGER) consortium to facilitate the automobile industry meeting more stringent 2003 Federal
Tier II and California LEV II emission regulations. Newer vehicles produce lower levels of
nitric oxide and other pollutants because of fuel injection where air-to-fuel ratios are optimized
by an on-board computer. These emission levels are reduced further by more efficient catalytic
converters. During Federal or State emission testing, the tailpipe exhaust levels are further
diluted with clean air and then collected using constant volume sampling bags; or by using the
new mini-diluter technology. The final concentration of nitric oxide measured could easily be
lower than 1 μmol/mol (ppm).
NIST developed the new SRMs in collaboration with AIGER who provided funding to
purchase candidate mixtures that were then certified by NIST, including monitoring the
mixtures for stability over a five year period. The new SRMs are provided in 30 liter (water
volume) aluminum compressed gas cylinders with a stainless steel valve with a CGA 660 valve
outlet. The SRM user will have more than 3600 liters of useable gas standard supplied from
this package.
Standard Reference Material (SRM) 2737
Standard Reference Material (SRM) 2738
March 2006
indirect impact on the Earth’s radiative forcing. For the most part, man’s activities are linked to
these emissions and account for a significant amount of the total carbon aerosol found in the
atmosphere. To assess impacts and distinguish sources of combustion aerosol, numerous
methods exist to quantify the amount of organic and black (soot) carbon, important in addressing
air quality issues and estimating the warming and cooling effects of aerosol on our climate
system. However, all these analytical methods are method dependent and result in various
definitions of what constitutes black carbon.
Researchers in the Analytical Microscopy Group of the Chemical
Science and Technology Laboratory (CSTL) and the Statistical
Modeling and Analysis Group of the Information Technology Lab
(ITL) have collaborated with SRI International (Menlo Park, CA) to
produce Reference Material (RM) 8785 Air Particulate Matter (PM)
on Filter Media1 and its Filter Blank (RM 8786). RM 8785 was
produced by resuspending SRM 1649a Urban Dust, sampling its fine
fraction (< 2.5 μm aerodynamic diameter) and filtering the PM2.5
onto nearly 2000 quartz-fiber filters. Filter
ID number and the gravimetrically determined
mass of fine SRM 1649a uniquely identify each
filter. RM 8785 is intended primarily for use in
the evaluation of analytical methods used to characterize the carbon
composition of atmospheric PM2.5 for national ambient air quality
standards (NAAQS) monitoring programs. Additionally, RM 8785 will
provide the atmospheric chemistry and ocean-sciences community with
a means to intercompare methods and laboratories for the measurement
of black carbon.
Through an inter–laboratory and –method comparison involving NIST,
the Desert Research Institute (Reno, NV) and Sunset Laboratories Inc.
(Tigard, OR), concentrations of total carbon, black carbon and organic
carbon were measured and values were assigned. Measurements were performed using two
widely used thermal-optical methods: the Interagency Monitoring of Protected Visual
Environments (IMPROVE) and the Speciation Trends Network-National Institute of
Occupational Safety and Health (STN-NIOSH). RM 8785 has been assigned a reference value
for total carbon concentration and information values for black and organic carbon
concentrations corresponding to each method.
Reference Material 8785
Reference Material 8786
March 2006 |
