Rapid procedure for the determination of residual acetone and 2-propanol in oilseed meals and flours

1975 ◽  
Vol 52 (9) ◽  
pp. 354-356 ◽  
Author(s):  
H. P. Dupuy ◽  
E. T. Rayner ◽  
S. P. Fore
Keyword(s):  
1963 ◽  
Vol 35 (9) ◽  
pp. 1307-1308 ◽  
Author(s):  
R. D. Tiwari ◽  
J. P. Sharma
Keyword(s):  

1973 ◽  
Vol 19 (7) ◽  
pp. 710-717 ◽  
Author(s):  
Luis E Mejer ◽  
Roberta C Blanchard

Abstract A method proposed by Kitabchi and Kitchell [Anal. Biochem. 34, 529 (1970)] for the fluorometric determination of plasma 11-hydroxycorticosteroids has been modified. It is simplified by eliminating centrifugations, by processing all samples consecutively (rather than in small groups), by using disposable test tubes, and by prealkalinizing standards and blanks as well as plasma samples. Specificity and sensitivity are increased by measuring fluorescence at 520 nm, with an excitation wavelength of 470 nm. Effects of prealkalinization and time of fluorescence development on final cortisol values were studied. Large fluorescence increases are possible after 60 min of fluorescence development. Cortisol recoveries were not changed by the use of phase-separating filter paper nor were cortisol values altered by partial aging of the fluorescence reagent. Sensitivity, specificity, accuracy, and precision of the proposed method are reported.


1974 ◽  
Vol 20 (11) ◽  
pp. 1460-1462 ◽  
Author(s):  
Naresh C Jain ◽  
Thomas C Sneath ◽  
Robert D Budd

Abstract A simple, rapid procedure is described for measuring amphetamine and methamphetamine in urine by gas chromatography, with use of a flame ionization detector. This method is sensitive to subtherapeutic concentrations (0.1 µg/ml or less), and is especially useful in clinical situations where an accurate and quantitative result is needed in less than 30 min. With the method, amphetamine and methamphetamine can be determined as the free bases on a 10% Apiezon L-10% KOH column and as their trifluoroacetamide derivatives on a 3% OV-17 column. This dual analysis eliminates false positives and any interfering substances that may be present in the urine, and is thus a specific method for the two drugs.


1942 ◽  
Vol 20c (8) ◽  
pp. 403-410 ◽  
Author(s):  
K. A. Clendenning

Neither the original Mannich–Lenz procedure nor its recently proposed revisions proved suitable for the polarimetric determination of starch in gluten. The principal defect lay in the means of removing or correcting for proteins dissolved along with the starch and there also was a need for improvements in technique of starch dispersion.In the present method, the starch of the gluten sample is dispersed by 15 min. boiling in a calcium chloride solution having a specific gravity of 1.30 and a pH of approximately 2.5. Frothing is controlled by the addition of one or two drops of n-octyl alcohol, constant volume being maintained during boiling by the addition of water. The proteins dissolved by this treatment are precipitated with 20% stannic chloride prior to filtration and polarization. This rapid procedure underestimates the starch content but the application of a factor to correct for the constant ratio of underestimation allows the real starch content to be determined with an accuracy of ±0.5%.


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