SRMs 1975 and 2975 are intended for use in evaluating analytical methods for the determination of selected polycyclic aromatic hydrocarbons (PAHs) in diesel particulate extracts and in diesel particulate matter and similar matrices. Ambient air particulates, especially diesel particulates, are important components targeted for investigation by the particulate matter (PM) 2.5 µm size fraction initiative of the Clean Air Act. There is an increased interest in the impact of diesel emissions on human health, in particular the mutagenic and carcinogenic parameters.
Bulk quantities of a new diesel particulate material were obtained from the filtering system of an industrial forklift. This material was identified by the U.S. Environmental Protection Agency (EPA) as a diesel particulate material with relatively high mutagenic activity. SRM 2975 was prepared from this bulk material and a portion of this same bulk diesel particulate matter was extracted with dichloromethane to prepare SRM 1975.
SRM 1975 was developed in response to the needs of both the environmental analytical and bioassay communities for a diesel particulate extract SRM to help reduce the variability associated with the solvent extraction of the particulate material. This SRM provides certified and reference values for selected polycyclic aromatic hydrocarbons. Reference values are provided for the concentrations of selected nitro-substituted PAHs, extract residue mass, and mutagenic activity. All of the chemical constituents for which certified and reference values that are provided in SRM 1975 were naturally present in the particulate material before extraction. A unit of SRM 1975 consists of four ampoules, each containing approximately 1.2 mL of a dichloromethane extract of diesel particulate matter.
SRM 2975 provides certified and reference values for selected polycyclic aromatic hydrocarbons in diesel particulate matter. In addition, reference or information values are provided for total extractable mass, particle size distribution, specific surface area, and the concentration of 1-nitropyrene. All of the chemical constituents for which certified, reference, and information values are provided in SRM 2975, are naturally present in the particulate material. A unit of SRM 2975 consists of a bottle containing 1 g of the diesel particulate matter.
These standards complement SRM 1650a Diesel Particulate Matter, a renewal and recertification of the same material used to create SRM 1650.
SRM Contact:
Bruce MacDonald
Technical Contact:
Stephen Wise
Sales and pricing information: SRM Sales Office
Tel: 301-975-6776
Fax: 301-948-3730
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Refractory Alloy MP-35-N
(Disk & Chip Forms)
MP-35-N is in a class of alloys comprised of cobalt, nickel, chromium, and molybdenum. They are characterized by ultrahigh strengths with good ductility and a high resistance to corrosion and oxidation. Due to these qualities, MP-35-N has a wide range of applications as an aerospace material, in medical devices, and as an advanced magnetic material.
SRMs 1775 and 2175 have certified values for 10 elements. Values for chromium, cobalt, iron, molybdenum, nickel, and titanium are given as mass fractions in %. Values for boron, manganese, sulfur, and vanadium are reported as mass fractions in mg/kg.
SRM 1775 is in the form of a disk, approximately 35 mm (1.38 in.) in diameter and 12.7 mm (0.5 in.) thick and is intended for use with optical emission and X-ray spectrometric methods of analysis. This material is the same lot as SRM 2175 supplied in chip form.
SRM 2175 is in the form of chips sized between 0.50 mm and 1.18 mm sieve openings (35 mesh and 16 mesh) and is intended for use primarily in chemical methods of analysis. A unit of SRM 2175 consists of 150 g of chips.
These SRMs also have reference values for aluminum, carbon, copper, and phosphorus.
SRM Contact:
srminfo
Technical Contact:
John Fassett
Sales and pricing information: SRM Sales Office
Tel: 301-975-6776
Fax: 301-948-3730
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Alloy elements used in steel production have a direct effect on the properties of the material produced. Nitrogen is an important element that is monitored in the steel manufacturing process as it contributes to the hardness of the resulting steel. A high nitrogen content makes steel unsuitable for many applications. The availability of the SRM will allow steel manufacturers to calibrate their optical emission spectrometers (OES) on the production floor and monitor the nitrogen levels during the manufacturing process.
The SRM is in the form of a disk 35 mm in diameter (1.38 in.) and 19 mm thick (0.75 in.). It is intended for use primarily in optical emission spectrometric methods of analysis.
Nitrogen analyses for value assignment were performed at NIST and cooperating laboratories using sample dissolution-Kjeldahl nitrogen determination, combustion infrared detection, and vacuum fusion, gas volume measurement
The certified value and uncertainty for nitrogen is reported as a mass fraction in mg/kg.
Certified Value of Nitrogen:
118.4 mg/kg ± 1.8 mg/kg
SRM Contact:
srminfo
Technical Contact:
Charles Beck
Sales and pricing information: SRM Sales Office
Tel: 301-975-6776
Fax: 301-948-3730
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Two new SRMs for the calibration of particle size distribution (PSD) measurement equipment have been developed by NIST, in support of the plasma-spray deposition coatings industry. SRM 1984 and SRM 1985 are tungsten carbide/cobalt materials that represent the two major tungsten carbide powder types used by industry for hard abrasion-resistant coatings: a fused and crushed powder, and a spray dried and sintered material, respectively. SRM 1984 (Acicular) is for use in the 9 µm to 30 µm particle size range. SRM 1985 (Spherical) is for use in the 18 µm to 55 µm particle size range. These SRMs complement the previously released SRM 1982 Zirconia Thermal Spray Powder-PSD, for high temperature coatings, that was developed for improved process reproducibility in the manufacture of high temperature coatings.
Each unit of SRM 1984 & SRM 1985 consists of a single bottle containing approximately 14 g of tungsten carbide/cobalt powder.
SRM Contact:
Nancy Trahey
Technical Contact:
James Kelly
Sales and pricing information: SRM Sales Office
Tel: 301-975-6776
Fax: 301-948-3730
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SRM 1990 is intended primarily for use as an alignment standard for single crystal diffractometry. The SRM consists of three chromium-doped single crystal aluminum oxide (ruby) spheres. Each sphere is nominally 152 µm in diameter with 1.3 µm sphericity. The spherical geometry was chosen to avoid corrections for absorption and produce reflections at high angles for copper and molybdenum radiation.
The certified lattice parameters of SRM 1990 at 25 °C are:
a: 0.476080 nm ± 0.000029 nm
c: 1.299568 nm ± 0.000087 nm
The certified values were obtained using ? (CuK?1) and ? (MoK?1). The estimated uncertainty accounts for uncertainty due to a small variation in chromium content, random errors of measurement, and the small uncertainty in ? (CuK?1) and ? (MoK?1). Other systematic effects such as absorption, extinction, and divergence were not found to be significant and are not included in the uncertainty estimate.
SRM Contact:
Carlos Beauchamp
Technical Contact:
Winnie Wong-Ng
Sales and pricing information: SRM Sales Office
Tel: 301-975-6776
Fax: 301-948-3730
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Ultra high molecular weight polyethylene (UHMWPE) is the primary material used in total orthopedic joint replacement implants. The success and stability of a replacement joint is directly affected by the specific properties of the material that is used in the device. Concerns about long-term durability of UHMWPE have created a need for a standard to test the properties of implant materials. Reference Material (RM) 8456 was developed for use in performance evaluations of orthopedic implant materials in order to help support the development of improved orthopedic joint replacement implants.
RM 8456 is intended primarily for use in the characterization of the physical properties of UHMWPE related to its use as a mechanical implant material. The properties reported are the Tensile: Young?s Modulus, Yield Strength, Ultimate Strength, and Elongation to Failure. Properties are given as mean values with their expanded uncertainties. Each unit of RM 8456 UHMWPE is supplied as a cylindrical polyethylene bar, with nominal dimensions of 7.62 cm (3.00 in.) diameter by 152.4 cm (60 in.) length. This RM is NOT intended for use in human implantation or any human biomedical device.
SRM Contact:
Joylene Thomas
Technical Contact:
John Tesk
Sales and pricing information: SRM Sales Office
Tel: 301-975-6776
Fax: 301-948-3730
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Elevated levels of uric acid in blood may be a sign of reduced kidney function and may lead to the painful inflammatory condition known as gout. Early diagnosis of elevated blood uric acid can prevent kidney damage and the onset of gout. This SRM helps assure that clinical laboratories can accurately determine blood uric acid, thus leading to better and more cost effective health care.
SRM 913a Uric Acid is certified as a chemical of known purity. It is intended primarily for use in the calibration and standardization of procedures for uric acid determinations employed in clinical analysis and for routine critical evaluation of the daily working standards used in these procedures.
The certified chemical purity is based upon results from several analytical techniques and was determined by measuring the mass fractions of impurities (including water and residue from ashing), summing the impurities, adding an allowance for undetected impurities, and subtracting this sum from 100 %.
Certified Chemical Purity: 99.6 % ± 0.1 %
Reference values for mass loss upon drying, residue after ashing, and molar extinction coefficients are also provided.
A unit of SRM 913a consists of one bottle containing 10 g of crystalline uric acid.
SRM Contact:
Jennifer Colbert
Technical Contact:
Michael Welch
Sales and pricing information: SRM Sales Office
Tel: 301-975-6776
Fax: 301-948-3730
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SRMs 211d & 2214
- Toluene Liquid Density and Isooctane Liquid Density
Liquid density is an important physical property of materials used in research and industry. Each day density measurements are used to solve a variety of technical and manufacturing problems. These range from quality control in the production of industrial liquids, petrochemical, and hydrocarbon fluids to measuring the sugar or alcohol concentrations of edible commodities in the food and beverage industries. The densitometers used for measuring liquid density require precise standards in order to be properly calibrated. SRM 211d Toluene Liquid Density and SRM 2214 Isooctane Liquid Density were developed to meet this need.
SRM 211d consists of high purity liquid toluene characterized for density, r (T), at three temperatures, 15 ° C, 20 ° C and 25 ° C. The certified value and uncertainty for the liquid density of toluene at 20 ° C is
866.828 kg/m3 ± 0.025 kg/m3.
SRM 2214 is a high purity liquid isooctane characterized for density, r (T), at three temperatures, 15 ° C, 20 ° C, and 25 ° C. The certified value and uncertainty for the liquid density of isooctane at 20 ° C is:
691.872 kg/m3 ± 0.035 kg/m3
Each unit of SRM 211d and SRM 2214 consists of five flame-sealed glass ampoules each ampoule containing approximately 5 mL of liquid.
SRM Contact:
Jennifer Colbert
Technical Contact:
Pedro Espina
Sales and pricing information: SRM Sales Office
Tel: 301-975-6776
Fax: 301-948-3730
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SRM 966
-
Trace Metals in Bovine Blood
National and international public health monitoring organizations such as the Centers for Disease Control and Prevention (CDC), U.S. Environmental Protection Agency (EPA), World Health Organization (WHO), and National Institute of Environmental Health Sciences (NIEHS) have expressed a continued interest in workplace and public health monitoring for methylmercury and cadmium in blood.
SRM 966 is a new frozen bovine whole blood standard with two different levels of organically bound lead, spiked inorganic cadmium, and spiked mercury (both methyl and inorganic forms). It is intended for use in evaluating the accuracy of lead, cadmium, and total mercury concentration determinations in whole blood. It can also be used for validating analytical methods and for providing traceability to working or secondary blood reference materials containing these constituents.
Lead concentrations in Level 1 and Level 2 and the cadmium concentrations and total mercury concentrations in Level 2 have been certified. All values are reported in concentration units of ?g/L except for lead, which has units of ?g/dL.
A unit of SRM 966 consists of four vials, two each of two different concentration levels. Each vial contains approximately 2 mL of frozen bovine blood.
SRM Contact:
Jennifer Colbert
Technical Contact:
Robert Vocke
Sales and pricing information: SRM Sales Office
Tel: 301-975-6776
Fax: 301-948-3730
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SRM 975a
- Isotopic Standard for Chlorine
SRM 975a was developed in response to the depletion of SRM 975, which was originally certified in 1965. Its impact was so significant that it promoted the revision of the atomic weight of chlorine (Cl) in the year it was produced.
Since then, researchers have used ocean water and the Standard Mean Ocean Chloride (SMOC) scale as a standard for total chloride. Recently, it has been noted that Cl isotopic values in nature vary, shifting the SMOC scale.
SRM 975a will not only function as a total Cl isotopic standard, but also as a certified artifact that will serve to stabilize the SMOC scale. SRM 975a is intended primarily for use as an isotopic standard. Purity of the NaCl is 99.89 % by mass. The certified isotopic compositions and the atomic weight of chlorine are given.
The certified values for the absolute abundance ratio of 35Cl/37Cl and isotopic compositions of 35Cl and 37Cl were derived by directly comparing nine randomly selected bottles of this material, measured in duplicate, with SRM 975. Measurements were made by thermal ionization mass spectrometry (TIMS) on a NIST designed solid source mass spectrometer utilizing a tantalum single filament procedure.
A unit of SRM 975a consists of 0.25 g of sodium chloride (NaCl).
SRM Contact:
Nancy Trahey
Technical Contact:
Robert Vocke
Sales and pricing information: SRM Sales Office
Tel: 301-975-6776
Fax: 301-948-3730
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SRM 1566b
- Oyster Tissue
Marine mollusks such as oysters, scallops and mussels concentrate and store heavy metals and other elements as well as toxins from surrounding waters. Studying the tissues of these marine bivalves can help marine scientists determine baseline levels of these constituents and thus monitor significant changes in the amount of potentially harmful levels in the environment.
SRM 1566b is certified for 22 elements and a new addition, methylmercury. Reference values are provided for nitrogen and seven additional elements including uranium and hydrogen. This renewal issue of the SRM can now also be used for quality control when analyzing food matrices that are low in fat and contain nearly equal amounts of carbohydrate and protein. Reference values are provided for proximates, protein nitrogen, total dietary fiber, selected fatty acids, and caloric content.
Information values are also provided for additional selected fatty acids.
A unit of SRM 1566b contains approximately 25 g of freeze-dried oyster tissue.
SRM Contact:
Jennifer Colbert
Technical Contact:
Robert Greenberg
Sales and pricing information: SRM Sales Office
Tel: 301-975-6776
Fax: 301-948-3730
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- SRMs 1632c, 1635, 2682b, 2683b, 2684b, 2685b & 2692b
NIST announces the release of certified values for mercury content for all seven NIST coal SRMs. These standards help support of the U.S. Clean Air Act and U.S. EPA, ASTM, and Electric Power Research Institute (EPRI) efforts to more accurately predict and control mercury emissions from coal combustion. Each certified value is based on a NIST primary method for mercury, isotope dilution cold vapor inductively coupled mass spectrometry (ID-CV-ICP-MS), recently developed by the NIST Analytical Chemistry Division.
In addition to mercury, the SRMs listed below are also characterized for other constituents of interest such as sulfur, ash content, and calorific value.
Certified Values for Mercury
Bituminous Coals:
SRM 1632c 93.9 µg/kg ± 3.7 µg/kg
SRM 2683b 90.0 µg/kg ± 3.6 µg/kg
SRM 2684b 97.4 µg/kg ± 4.7 µg/kg
SRM 2685b 146.2 µg/kg ± 10.6 µg/kg
SRM 2692b 133.3 µg/kg ± 4.1 µg/kg
Subbituminous Coals:
SRM 1635 10.9 µg/kg ± 1.0 µg/kg
SRM 2682b 108.8 µg/kg ± 2.9 µg/kg
A unit of each SRM consists of 50 g (SRM 1635, 75g) of finely powdered coal ground to pass a 250 ?m (60 mesh) sieve and homogenized.
SRM Contact:
Bruce MacDonald
Technical Contact:
Stephen Long
Sales and pricing information: SRM Sales Office
Tel: 301-975-6776
Fax: 301-948-3730
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SRM 2567
- Catalyst Package for Lubricant Oxidation to be Discontinued
(ASTM Sequence IIIE Engine Test)
SRM 2567 will be discontinued December 30, 2001, with no plans for renewal, because ASTM testing requirements are changing and alternative materials are now commercially available. This notice is intended to alert users of SRM 2567 and provide a time of transition to alternative materials. Further information regarding ASTM testing and alternative materials may be obtained from ASTM D02.09G1.
SRM Contact:
Bruce MacDonald
ASTM D02.09G1 Contact: Greg Miller
Tel.: 517-496-2309
Fax: 517-496-3438
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- SRMs 3191 - 3199
The packaging of SRMs 3191-3199 has been under investigation for some time. This article is meant to serve as an update to the previous article regarding the packaging of these SRMs. SRMs 3193, 3194, and 3195 will be packaged in 50 mL ampoules in sets of eight. The packaging of SRMs 3192 and 3196 in ampoules is still being investigated. SRMs 3191, 3198, and 3199 will continue to be packaged in 500 mL bottles.
SRM Contact:
Bruce MacDonald
Technical Contact:
Rubina Shreiner
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NIST Centennial Celebration at PITTCON 2001
To celebrate the One Hundredth Anniversary
of
the National Institute of Standards and Technology
The Chemical Reference Materials Manufacturers Association,
the Specialty Gas Industry, and
the Pittsburgh Conference
invite you to attend a special poster session and reception
La Nouvelle Ballroom
Second floor
Morial Convention Center
Monday, March 5, 2001
from 5:15 to 6:30 PM
SRM Quarterly is published by the Standard Reference Materials Program, Office of Measurement Services, National Institute of Standards and Technology, U.S. Department of Commerce.
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