Methods of test for petroleum and its products. Crude petroleum. Determination of water. Distillation method

1997 ◽  
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


2017 ◽  
Vol 36 (2) ◽  
pp. 643
Author(s):  
J. O. Ozuomba ◽  
A. Emmanuel ◽  
C. U. Ozuomba ◽  
M. C. Udoye

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


1964 ◽  
Vol 47 (3) ◽  
pp. 471-473
Author(s):  
John R Hohmaxn ◽  
Joseph Levine

Abstract A method using column partition chromatographic separation has been developed for the determination of nitroglycerin in soluble, sublingual glyceryl trinitrate tablets. A mixture of the phenoldisulfonic acid reagent and acetic acid is used to extract the nitroglycerin from the eluate. Quantitative results are obtained by measuring the color of the nitrated phenoldisulfonic acid that is formed. Results by the method are in agreement with those obtained by the USP distillation method and an infrared assay.


1967 ◽  
Vol 50 (3) ◽  
pp. 605-615
Author(s):  
R W Storherr ◽  
Edward J Murray ◽  
I Klein ◽  
Lynn A Rosenberg

Abstract The technique of sweep co-distillation developed for organophosphate pesticides in fruits and vegetables was expanded for application to organophosphate and chlorinated hydrocarbon pesticides in edible oils. A modified longer and wider Storherr tube and heating assembly was used in this work and 3 mm diameter glass beads replaced the glass wool packing used in crop work. The work on oils was performed at 248 ± 3°C with a nitrogen flow of 600 ml/min and injection of a sweeping solvent every 3 minutes for 30 minutes. Phosphate pesticides were analyzed by GLC with a potassium thermionic detector and chlorinated pesticides were determined by ECGLC, after a micro Florisil column was used to eliminate extraneous peaks. Recoveries of ten phosphate pesticides from nine edible oils ranged from 74 to 100% at fortification levels of 0.04 to 6.25 ppm; average recoveries for the individual pesticides were 90—99%. Average recoveries for the chlorinated pesticides ranged from a low of 75% for Tedion to a high of 98% for endrin and dieldrin. Sensitivity of 0.01 is readily obtainable for compounds such as parathion and heptachlor cpoxide. The sweep co-distillation method is suitable for the rapid determination of the 14 chlorinated and 10 organophosphate pesticides tested in edible oils


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