A Turbulent Drier-Extractor and a Wide-Interface Extractor

1964 ◽  
Vol 10 (11) ◽  
pp. 1007-1024
Author(s):  
Frederic E Holmes
Keyword(s):  
Reference Standard ◽  
Wide Interface

Abstract A simpler modification of an original turbulent drier-extractor with provision for measuring moisture is presented, as well as methods for determination of lipids in serum and in urine in the wide-interface extractor, and a new use for the wide-interface extractor in washing extracts from the drier-extractor. The two extraction units described may also serve as a reference standard and may be preferred for routine lipid assays.

scholarly journals Determination of Organosulfides from Onion Oil

Foods ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 884 ◽  
Author(s):  
Maranda S. Cantrell ◽  
Jared T. Seale ◽  
Sergio A. Arispe ◽  
Owen M. McDougal
Keyword(s):  
Diethyl Ether ◽  
Steam Distillation ◽  
Extraction Efficiency ◽  
Agricultural Products ◽  
Gas Chromatography Mass Spectrometry ◽  
Diallyl Disulfide ◽  
Reference Standard ◽  
Internal Reference ◽  
Internal Reference Standard

Qualitative and semi-quantitative analysis of organosulfides extracted from oil obtained by steam distillation of yellow onions was performed by gas chromatography-mass spectrometry (GC-MS). The extraction efficiency of organosulfides from onion oil was evaluated across four solvents: dichloromethane; diethyl ether; n-pentane; and hexanes. Analysis of solvent extracted organosulfides by GC-MS provided qualitative results that support the use of dichloromethane over other solvents based on identification of 27 organosulfides from the dichloromethane extract as compared to 10 from diethyl ether; 19 from n-pentane; and 17 from hexanes. Semi-quantitative evaluation of organosulfides present in the dichloromethane extract was performed using diallyl disulfide as the internal reference standard. Three organosulfides were detected in the extract at ≥5 mg/kg; 18 organosulfides between 3–5 mg/kg; and six organosulfides at <3 mg/kg. The E/Z isomers of 1-propenyl propyl trisulfide were among the most prevalent components extracted from the onion oil across all solvents; and 3,6-diethyl-1,2,4,5-tetrathiane was among the most abundant organosulfides in all solvents except hexanes. The method described here for the extraction of organosulfides from steam distilled onion oil surveys common solvents to arrive at a qualitative and semi-quantitative method of analysis for agricultural products involving onions; onion oil; and secondary metabolites of Allium spp.

Gossypol Acetic Acid as a Reference Standard in the Determination of Gossypol

1960 ◽  
Vol 43 (2) ◽  
pp. 329-331
Author(s):  
Carroll L Hoffpauir ◽  
James A Harris ◽  
J P Hughes
Keyword(s):  
Acetic Acid ◽  
Reference Standard ◽  
Gossypol Acetic Acid

scholarly journals Simultaneous Determination of Multiple Sesquiterpenes in Curcuma wenyujin Herbal Medicines and Related Products with One Single Reference Standard

Molecules ◽  
2013 ◽  
Vol 18 (2) ◽  
pp. 2110-2121 ◽  
Author(s):  
Jing-Jing Zhu ◽  
Yue-Wei An ◽  
Guang Hu ◽  
Guo-Ping Yin ◽  
Qi-Wei Zhang ◽  
...  
Keyword(s):  
Simultaneous Determination ◽  
Herbal Medicines ◽  
Reference Standard

Standardization of immunochemical determinations of serum albumin.

1981 ◽  
Vol 27 (5) ◽  
pp. 736-738 ◽  
Author(s):  
J W Keyser ◽  
R Fifield ◽  
G L Watkins
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Normal Human Serum ◽  
Reference Standard ◽  
Protein Nitrogen ◽  
Critical Comparison ◽  
Normal Human ◽  
Theoretical Results

Abstract When we compared four commercially available preparations of human serum albumin with the human serum standard IFCC 74/1 by radial immunodiffusion, by immunoprecipitation turbidimetry, by laser nephelometry, and by "rocket" immunoelectrophoresis, three of the preparations gave almost "theoretical" results with the immunoprecipitation turbidimetric method. Results by the other three methods tended inconsistently to be low. Four pools of normal human serum were also analyzed for albumin by these four immunochemical methods, again with IFCC 74/1 as the reference standard. The results were virtually identical with those obtained by fractionation with 1.8 mol/L sodium sulfate and determination of protein nitrogen in the filtrate. We suggest that a combination of (a) fractionation of a pool of normal human serum in this way and (b) critical comparison with selected commercial preparations of human serum albumin will permit standardization of the serum albumin determination.

Liquid Chromatographic Determination of Lactose Purity: Collaborative Study

1984 ◽  
Vol 67 (5) ◽  
pp. 899-901
Author(s):  
Janice R Saucerman ◽  
Charles E Winstead ◽  
◽  
P J Casaletto ◽  
N J DeAngelis ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Study Data ◽  
Reference Standard ◽  
Mobile Phase Flow Rate ◽  
Equal Concentration ◽  
Liquid Chromatographic

Abstract Results from 8 laboratories are presented for the collaborative study of a proposed method for quantitative liquid chromatographic (LC) determination of lactose purity. Each laboratory was provided with 10 blind duplicate, edible-grade lactose samples plus a lactose reference standard and a fructose internal standard. Testing required the comparison of aqueous 2% lactose sample solution against a reference standard of equal concentration and quantitation by using a fructose internal standard. The LC system specified an isocratic acetonitrilewater (80 + 20) mobile phase, flow rate 2.0 mL/min, and chromatographic separation on a carbohydrate column. Compounds were detected by using refractive index. Statistical analysis for all study data indicates excellent between-laboratory precision with a coefficient of variation (CV) range of 0.53-1.37% and an overall average of 0.977%. Statistical analysis after excluding outliers showed equally good repeatability and reproducibility of less than 1 % and 1.5% CV, respectively. The method has been adopted official first action.

Establishment of a Standard Assay Method for Human Thrombomodulin and Determination of the Activity of the Japanese Reference Standard

Biologicals ◽  
2002 ◽  
Vol 30 (1) ◽  
pp. 69-76 ◽  
Author(s):  
Shingo Niimi ◽  
Tadashi Oshizawa ◽  
Masaaki Naotsuka ◽  
Sumiaki Ohba ◽  
Akira Yokozawa ◽  
...  
Keyword(s):  
Assay Method ◽  
Reference Standard ◽  
Standard Assay
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