Long-term stability of sulfur dioxide permeation tube standard reference materials

1992 ◽  
Vol 344 (6) ◽  
pp. 229-233 ◽  
Author(s):  
G. D. Mitchell ◽  
W. D. Dorko ◽  
P. A. Johnson
Keyword(s):  
Sulfur Dioxide ◽  
Reference Materials ◽  
Standard Reference Materials ◽  
Term Stability ◽  
Long Term Stability ◽  
Permeation Tube

scholarly journals The importance of cylinder passivation chemistry for preparation and long-term stability of multicomponent monoterpene primary reference materials

2018 ◽  
Author(s):  
Nicholas D. C. Allen ◽  
David R. Worton ◽  
Paul J. Brewer ◽  
Céline Pascale ◽  
Bernhard Niederhauser
Keyword(s):  
Reference Materials ◽  
Chemical Reactivity ◽  
International System ◽  
High Chemical ◽  
Term Stability ◽  
Long Term Stability ◽  
System Of Units ◽  
Primary Reference ◽  
High Chemical Reactivity

Abstract. Monoterpenes play an important role in atmospheric chemistry due to their large anthropogenic and biogenic emission sources and high chemical reactivity. As a consequence, measurements are required to assess how changes in emissions of monoterpenes impact air quality. Accurate and comparable measurements of monoterpenes in indoor and outdoor environments require gaseous primary reference materials (PRMs) that are traceable to the international system of units (SI). PRMs of monoterpenes are challenging to produce due to the high chemical reactivity and low vapour pressures of monoterpenes and also their propensity to convert into other compounds, including other terpenes. In this paper, the long-term stability of gravimetrically prepared static monoterpene PRMs produced in differently passivated cylinders, including sampling canisters, was assessed. We demonstrate that static PRMs of multiple monoterpenes can be prepared and used as a suitable long-term standard. For the first time the effect of cylinder pressure and decanting from one cylinder to another on the chemical composition and amount fraction of monoterpenes was also studied. Gravimetrically prepared PRMs of limonene in high pressure cylinders were compared to a novel portable dynamic reference gas generator based on dilution of pure limonene vapour emitted from a permeation tube.

scholarly journals Revalidation and Long-Term Stability of National Institute of Standards and Technology Standard Reference Materials 1566, 1567, 1568, and 1570

2000 ◽  
Vol 83 (5) ◽  
pp. 1121-1134 ◽  
Author(s):  
David L Anderson ◽  
William C Cunningham
Keyword(s):  
Activation Analysis ◽  
Reference Materials ◽  
Rice Flour ◽  
Standard Reference Materials ◽  
National Bureau ◽  
Oyster Tissue ◽  
Long Term Stability ◽  
Technology Standard ◽  
Mass Fractions

Abstract Multiple units of Standard Reference Materials (SRMs) 1566 Oyster Tissue, 1567 Wheat Flour, 1568 Rice Flour, and 1570 Trace Elements in Spinach, produced by the National Institute of Standards and Technology (NIST, then the National Bureau of Standards), were analyzed 17–20 years after the original certification dates and 12–15 years after the certificates became invalid. Instrumental neutron activation analysis and thermal neutron prompt (γ-ray activation analysis were used to measure mass fractions for 27 elements in these SRMs to revalidate them for use in quality assurance (QA) programs required for food analysis programs within the U.S. Food and Drug Administration. With the exception of Se in SRM 1567, all element mass fractions were in agreement with certified values and literature data. Some evidence of B loss from SRM 1568 was observed. These materials were judged to be suitable for continued use in QA programs. Findings showed that these matrixes exhibited stability of moisture, mass fraction, and weight basis for far longer (≥15 years) than was indicated by the 5-year validity statement on the NIST Certificates of Analysis.

Long-term stability of relationships between reference materials for thromboplastins

2006 ◽  
Vol 96 (08) ◽  
pp. 210-214 ◽  
Author(s):  
Anton M. H. P. van den Besselaar ◽  
Armando Tripodi ◽  
Thomas P. J. Linsinger
Keyword(s):  
Reference Materials ◽  
World Health ◽  
Essential Requirement ◽  
Significance Level ◽  
Term Stability ◽  
Long Term Stability ◽  
The World ◽  
Health Organization ◽  
The Relationship

SummaryReference materials for thromboplastins are available from the World Health Organization (WHO) and the European Commission (EC). The long-term stability of the reference materials is an essential requirement and must be monitored. The relationship between two reference materials for rabbit thromboplastin, i. e. ERM-AD149 (EC) and RBT/90 (WHO), has been monitored in the period 1996–2002. No significant trend with time was detected. In addition,the relationship between ERM-AD149 and the reference material for bovine thromboplastin (i. e. OBT/79) has been determined in 1994 and in 2005 in multicentre studies (n = 11 and n = 9, respectively). No significant changes were observed in the relationships between these reference materials when all results were included (5% significance level).

scholarly journals The importance of cylinder passivation for preparation and long-term stability of multicomponent monoterpene primary reference materials

2018 ◽  
Vol 11 (12) ◽  
pp. 6429-6438 ◽  
Author(s):  
Nicholas D. C. Allen ◽  
David R. Worton ◽  
Paul J. Brewer ◽  
Celine Pascale ◽  
Bernhard Niederhauser
Keyword(s):  
Reference Materials ◽  
Chemical Reactivity ◽  
International System ◽  
High Chemical ◽  
Term Stability ◽  
Long Term Stability ◽  
System Of Units ◽  
Primary Reference ◽  
High Chemical Reactivity

Abstract. Monoterpenes play an important role in atmospheric chemistry due to their large anthropogenic and biogenic emission sources and high chemical reactivity. As a consequence, measurements are required to assess how changes in emissions of monoterpenes impact air quality. Accurate and comparable measurements of monoterpenes in indoor and outdoor environments require gaseous primary reference materials (PRMs) that are traceable to the international system of units (SI). PRMs of monoterpenes are challenging to produce due to the high chemical reactivity and low vapour pressures of monoterpenes and also their propensity to convert into other compounds, including other terpenes. In this paper, the long-term stability of gravimetrically prepared static monoterpene PRMs produced in differently passivated cylinders, including sampling canisters, was assessed. We demonstrate that static PRMs of multiple monoterpenes can be prepared and used as a suitable long-term standard. For the first time the effect of cylinder pressure and decanting from one cylinder to another on the chemical composition and amount fraction of monoterpenes was also studied. Gravimetrically prepared PRMs of limonene in high pressure cylinders were compared to a novel portable dynamic reference gas generator based on dilution of pure limonene vapour emitted from a permeation tube.

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