A rapid procedure for the determination of residual hexane in oilseed meals and flours

1972 ◽  
Vol 49 (2) ◽  
pp. 129-131 ◽  
Author(s):  
Sara P. Fore ◽  
H. P. Dupuy
Keyword(s):  
Rapid Procedure ◽  
Residual Hexane

A rapid procedure for the separation and determination of 3,4-dimethoxyphenylethylamine

1967 ◽  
Vol 18 (3) ◽  
pp. 563-566 ◽  
Author(s):  
W.H. Vogel ◽  
D. Ahlberg
Keyword(s):  
Rapid Procedure

Gas Chromatographic Determination of Residual Hexane in Modified Hop Extract

1972 ◽  
Vol 55 (6) ◽  
pp. 1226-1227
Author(s):  
Mark A Litchman ◽  
Lewis A Turano ◽  
Ronald P Upton
Keyword(s):  
Liquid Chromatography ◽  
Quantitative Determination ◽  
Chromatographic Determination ◽  
Methanol Solution ◽  
Chromatographic Column ◽  
Gas Liquid Chromatography ◽  
Porapak Q ◽  
Residual Hexane ◽  
Head Space

Abstract A method is described for the quantitative determination of hexane in modified hop extract by head-space gas-liquid chromatography. A sample of extract is weighed into a serum vial and water-methanol solution is added. The vial is sealed tightly and heated 1 hr in a 70°C bath. A sample of the head-space gas over the solution is injected onto a Porapak Q gas chromatographic column for determination. Recovery of 2–29 ppm hexane added to potassium isohumulone was 95.5–114.8%. The method may be applicable to other hop extracts.

Letters to the Editor: A RAPID PROCEDURE FOR THE DETERMINATION OF SERUM CHOLESTEROL*

1952 ◽  
Vol 12 (9) ◽  
pp. 1245-1246 ◽  
Author(s):  
SIDNEY PEARSON ◽  
SIDNEY STERN ◽  
THOMAS H. MCGAVACK
Keyword(s):  
Serum Cholesterol ◽  
Letters To The Editor ◽  
Rapid Procedure

A Rapid Procedure of the Determination of Nitro Groups in Semimicro and Micro Scales.

1963 ◽  
Vol 35 (9) ◽  
pp. 1307-1308 ◽  
Author(s):  
R. D. Tiwari ◽  
J. P. Sharma
Keyword(s):  
Rapid Procedure

Fluorometric Determination of Plasma 11-Hydroxycorticosteroids. I. Rapid Procedure for Clinical Screening

1973 ◽  
Vol 19 (7) ◽  
pp. 710-717 ◽  
Author(s):  
Luis E Mejer ◽  
Roberta C Blanchard
Keyword(s):  
Small Groups ◽  
Excitation Wavelength ◽  
Plasma Samples ◽  
Fluorometric Determination ◽  
Clinical Screening ◽  
Rapid Procedure ◽  
Specificity And Sensitivity ◽  
Accuracy And Precision ◽  
Sensitivity Specificity

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.

Rapid Gas-Chromatographic Determination of Amphetamine and Methamphetamine in Urine

1974 ◽  
Vol 20 (11) ◽  
pp. 1460-1462 ◽  
Author(s):  
Naresh C Jain ◽  
Thomas C Sneath ◽  
Robert D Budd
Keyword(s):  
Gas Chromatography ◽  
Quantitative Result ◽  
Chromatographic Determination ◽  
Flame Ionization Detector ◽  
Specific Method ◽  
Ionization Detector ◽  
Rapid Procedure ◽  
Flame Ionization ◽  
Dual Analysis

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.

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):  
Rapid Procedure

POLARIMETRIC DETERMINATION OF STARCH IN CEREAL PRODUCTS: I. RAPID DETERMINATION OF STARCH IN CRUDE GLUTEN

1942 ◽  
Vol 20c (8) ◽  
pp. 403-410 ◽  
Author(s):  
K. A. Clendenning
Keyword(s):  
Present Method ◽  
Chloride Solution ◽  
Rapid Determination ◽  
Starch Content ◽  
Calcium Chloride Solution ◽  
Stannic Chloride ◽  
Constant Ratio ◽  
Cereal Products ◽  
Rapid Procedure

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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