Determination of Plasma Potentials and Ion Energies by Ion Extraction and Energy Analysis

1966 ◽  
Vol 37 (10) ◽  
pp. 1308-1310 ◽  
Author(s):  
C. W. Erickson
1957 ◽  
Vol 24 (1) ◽  
pp. 144-147
Author(s):  
G. P. Fisher

Abstract Charts, based on classical bending-energy analysis, are presented for the determination of critical design moments in symmetrical ring girders varying in shape from circular through round to sharp-cornered rings. The girders are subjected to uniform normal loading in the plane of the ring. Location and magnitude of all critical bending moments are given, from which the maximum bending moment is easily selected.


1987 ◽  
Vol 70 (1) ◽  
pp. 64-68 ◽  
Author(s):  
J Ian Gray ◽  
Michael A Stachiw

Abstract A collaborative study was conducted on the U.S. Food and Drug Administration (FDA) dichloromethane extraction method for determining volatile N-nitrosamines in baby bottle rubber nipples. Following dichloromethane extraction, A'-nitrosamines were determined by gas chromatography-thermal energy analysis. Six pairs of blind duplicate rubber nipple samples representing 6 lots were analyzed by 11 collaborating laboratories. All samples were portions taken from equilibrated composites of cut-up rubber nipples obtained from manufacturers in the United States. Recoveries of the internal standard (N-nitrosodipropylamine) at approximately 20 ppb ranged from 10 to 120%. Reproducibility relative standard deviations (RSDJ were between 35 and 45% for N-nitrosamine levels from 10 to 20 ppb. However, when data from laboratories with recoveries less than 75% were excluded (this is now specified in the method), RSD„ values were between 11 and 32% for N-nitrosamine levels from 6 to 26 ppb. Values were consistent with or better than those reported for other analytical techniques designed to quantitate trace contaminants at the low ppb level, e.g., afiatoxin in foods. The method has been adopted official first action for the quantitation of volatile N-nitrosamines in baby bottle rubber nipples.


1995 ◽  
Vol 78 (6) ◽  
pp. 1435-1439
Author(s):  
Walter Fiddler ◽  
John W Pensabene ◽  
Robert C Doerr ◽  
Robert A Gates

Abstract The modification of a newly developed method for determination of apparent total N-nitroso compounds by chemical denitrosation and chemiluminescence detection of nitric oxide (thermal energy analysis) is described. The minimum level of reliable measurement was 0.1 ppm, and the repeatability of the method was 0.2 ppm, based on the response of N-nitrosoproline (NPro). Seventy-three samples of cured-meat products, including frankfurters, bacon, and ham, were examined; 50 samples contained less than 1 ppm. The largest amounts, up to 24.8 ppm, were detected in canned corned beef. This method has several advantages over other methods.


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