scholarly journals Determination of oxygen in sodium by vacuum distillation method

1972 ◽  
Vol 21 (7) ◽  
pp. 936-938 ◽  
Author(s):  
Masao TAKAHASHI ◽  
Misao OUCHI
1983 ◽  
Vol 20 (12) ◽  
pp. 1032-1038 ◽  
Author(s):  
Takao SAKAP ◽  
Minoru GUNJI ◽  
Seio MATSUMOTO ◽  
Yoichiro ISHII

1948 ◽  
Vol 20 (12) ◽  
pp. 1146-1150 ◽  
Author(s):  
J. C. Hillyer ◽  
A. J. Deutschman

1984 ◽  
Vol 67 (1) ◽  
pp. 20-21
Author(s):  
Donald C Havery ◽  
Gracia A Perfetti ◽  
Fazio Thomas

Abstract A rapid column elution method has been developed for the determination of N-nilrosodimethylamine (NDMA) in malt. The average recovery of NDMA added to malt at the 10 ppb level was 87%. When a single malt sample was analyzed 10 times, the NDMA found averaged 8.1 ppb with a coefficient of variation of 3.93%. In a study of 15 malt samples, data obtained by the column elution method were in good agreement with those from a vacuum distillation method.


Author(s):  
P.F. Collins ◽  
W.W. Lawrence ◽  
J.F. Williams

AbstractA procedure for the automated determination of ammonia in tobacco has been developed. Ammonia is extracted from the ground tobacco sample with water and is determined with a Technicon Auto Analyser system which employs separation of the ammonia through volatilization followed by colourimetry using the phenate-hypochlorite reaction. The procedure has been applied to a variety of tobaccos containing from 0.02 to 0.5 % ammonia with an overall relative standard deviation of 2 %. The accuracy of the procedure as judged by recovery tests and by comparison to a manual distillation method is considered adequate


1988 ◽  
Vol 71 (6) ◽  
pp. 1110-1115
Author(s):  
Alfred M Gottscho ◽  
Jeen-Lee Lin ◽  
William N Duck ◽  
Thomas A Losty

Abstract The use of AOAC standard methods for the determination of nicotine in commercial tobacco products is shown to be inappropriate. The methods do not provide for suitable sample preparation of these products for the analysis and, in addition, they yield high results. Evidence is presented that the nicotine or total alkaloids measured includes artifact nicotine. The distillation method was developed at a time when the complex alkaloid chemistry of tobacco was unknown, and does not take into consideration the possible contribution of substances in tobacco capable of contributing falsely to the result. The Cundiff-Markunas method, developed more recently, also fails to account for this effect—probably because it was designed to produce results matching those of the distillation method. Replacement of the standard methods is proposed and some alternative procedures are suggested


1988 ◽  
Vol 71 (3) ◽  
pp. 504-508
Author(s):  
Anthony J Malanoski ◽  
Wertice J Smith ◽  
Thomas Phillipo

Abstract Three methods, the mineral oil distillation (MOD), the dry column (DC), and a low temperature vacuum distillation (LTVD), for the determination of iV-nitrosopyrrolidine in dry-cured and pump-cured bacon were compared. Each method uses the thermal energy analyzer for the determinative step. The coefficients of variation for repeatability were 10.3% (MOD), 7.2% (DC), and 9.1% (LTVD) for the dry-cured bacon study and 8.7% (MOD), 8.5% (DC), and 7.1% (LTVD) for the pump-cured bacon study. The pooled coefficients of variation for between-method reproducibility were 11.8% for the drycured bacon and 10.8% for the pump-cured bacon. The pooled coefficients of variation for repeatability were 9.0% for the dry-cured bacon and 8.2% for the pump-cured bacon. These values compare favorably with the values from previous collaborative or validation studies of the individual methods, and the methods can be considered to be equivalent


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