A rapid method for determining the specific activity of methylene-14C citric acid in cell extracts

1969 ◽  
Vol 47 (12) ◽  
pp. 1137-1140 ◽  
Author(s):  
B. T. Hodgson ◽  
J. G. Aldous ◽  
A. H. Patterson
Keyword(s):  
Citric Acid ◽  
Rapid Method ◽  
Spectrophotometric Method ◽  
Liquid Scintillation ◽  
Specific Activity ◽  
Cell Extracts ◽  
Large Numbers

The microchemical spectrophotometric method for the determination of citric acid has been found to be sufficiently specific to permit its use for the measurement of specific activity, provided the labelling occurs in the noncarboxyl carbon atoms of the molecule. The simplicity of the method permits determinations to be carried out simultaneously on large numbers of samples especially if liquid-scintillation techniques are employed for the measurement of radioactivity.

scholarly journals A RAPID METHOD FOR THE DETERMINATION OF CITRIC ACID

1948 ◽  
Vol 175 (2) ◽  
pp. 849-855 ◽  
Author(s):  
Murray. Saffran ◽  
Orville F. Denstedt
Keyword(s):  
Citric Acid ◽  
Rapid Method

DEFINITIVE IDENTIFICATION OF MICROQUANTITIES OF RADIOACTIVE STEROIDS BY RECRYSTALLIZATION TO CONSTANT SPECIFIC ACTIVITY

1965 ◽  
Vol 49 (2_Suppl) ◽  
pp. S7-S77 ◽  
Author(s):  
Leonard R. Axelrod ◽  
Charles Matthijssen ◽  
Joseph W. Goldzieher ◽  
Jean E. Pulliam
Keyword(s):  
Liquid Scintillation ◽  
Specific Activity ◽  
Inorganic Materials ◽  
Dual Isotope ◽  
Advantages And Disadvantages ◽  
Yield Values ◽  
Solvent Systems ◽  
Identification Techniques ◽  
Constant Specific Activity

ABSTRACT Studies of steroid metabolism using isotopically-labeled compounds at physiological levels present unique problems in the identification of the metabolites and in the demonstration of their radiochemical purity. The submicrogram quantities of material available preclude the use of classical identification techniques. The character of the evidence obtained, the advantages and disadvantages of chromatographic and countercurrent distribution methods are discussed. Crystallization to constant specific activity is a recognized method for demonstrating that a substance is not radiochemically impure. Its parameters have never been accurately defined. Its true power is achieved only when it is preceded by extensive purification of the material to be characterized. In this way, the unknown material is first categorized by its migration rate in various solvent systems, and then by its crystalline identity with the carrier compound. The likelihood of two dissimilar steroids being both isopolar and isomorphic is held to be remote. Liquid scintillation spectrometry and gravimetry are the techniques used for the determination of constant specific activity. This method for measurement of radioactivity is extremely flexible, sensitive, and lends itself to dual-isotope experiments. Gravimetry under standardized conditions is suitably precise and much more generally applicable than spectroscopic quantitation. The parameters of the technique of rapid, forced microcrystallization are analyzed. In particular, the problem of contamination of crystals is analyzed in detail, and it is pointed out that classical concepts of purification by crystallization, developed chiefly in connection with ionic inorganic materials, must be modified when applied to nonionic steroid compounds. A mathematical analysis of the errors inherent in this technique indicates that 3 successive crystallizations of a pure radioactive compound should yield values for the specific activity which are within ± 5 % of the average of the 3 values.

THE DEVELOPMENT OF A RADIOIMMUNOASSAY FOR OXYTOCIN: RADIO-IODINATION, ANTIBODY PRODUCTION AND SEPARATION TECHNIQUES

1970 ◽  
Vol 46 (2) ◽  
pp. 269-278 ◽  
Author(s):  
T. CHARD ◽  
M. J. KITAU ◽  
J. LANDON
Keyword(s):  
Lymph Node ◽  
Human Plasma ◽  
Rapid Method ◽  
Ammonium Sulphate ◽  
Antibody Production ◽  
Specific Activity ◽  
High Specific Activity ◽  
Separation Techniques ◽  
Ammonium Sulphate Precipitation

SUMMARY A simple and rapid method is described for labelling oxytocin with 131I at a high specific activity. This method is compared with those of previous workers. A satisfactory antiserum has been raised by direct intra-lymph node injection of oxytocin adsorbed to carbon microparticles. A number of methods for separating antibody-bound from free oxytocin are described, and reasons given for preferring a procedure using ammonium sulphate precipitation. These data form the basis for developing a radioimmunoassay intended for the determination of oxytocin in human plasma.

Rapid Spectrophotometric Method for Determination of 2-Aminobutane in Postharvest Dips

1978 ◽  
Vol 61 (4) ◽  
pp. 1001-1003
Author(s):  
Harvey J Baker
Keyword(s):  
Rapid Method ◽  
Carbon Disulfide ◽  
Spectrophotometric Method ◽  
Cupric Ion ◽  
Extractable Complex

Abstract A rapid method is described for measuring 2-aminobutane in postharvest dip fluids. Samples of the dip fluid are diluted to bring the 2-aminobutane content in the range 500—5000 μg and reacted with carbon disulfide and cupric ion to form a chloroform-extractable complex measured spectrophotometrically at 430 nm. The accuracy and reproducibility of the method are comparable with the more lengthy modified product and residue methods.

scholarly journals Quantitative determination of Levomepromazine in pharmaceuticals by spectrophotometric method as its sulfoxide

2020 ◽  
Vol 8 (1) ◽  
pp. 117-124
Author(s):  
Olena Mozgova ◽  
Mykola Blazheyevskiy
Keyword(s):  
Sodium Chloride ◽  
Citric Acid ◽  
Quantitative Determination ◽  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Present Method ◽  
Limit Of Quantification ◽  
Derivatizing Agent ◽  
Sensitive Method

The oxidative derivatization method using Diperoxyazelaic acid for the indirect spectrophotometric determination of Levomepromazine hydrochloride is presented. Diperoxyazelaic acid is introduced as a derivatizing agent for Levomepromazine, yielding the sulfoxides. This reaction product was successfully used for the spectrophotometric determination of the Levomepromazine hydrochloride. The UV spectroscopic detection of the sulfoxide proved to be a more robust and sensitive method. The elaborated method allowed the determination of Levomepromazine hydrochloride in the concentration range of 3-150 µg/mL. The limit of quantification, LOQ (10S) is 2.85 µg/mL. A new spectrophotometric technique was developed and the possibility of quantitative determination of Levomepromazine in Tisercin Solution for Injection 25mg/mL was demonstrated. The present method is precise, accurate and other excipients: anhydrous citric acid, monothioglycerol, sodium chloride did not interfere. RSD = 1.24 % (δ = –0.02 %).

scholarly journals A Rapid Method for the Determination of Isolated Trans Isomers in Fats and Oils by IR Spectrophotometric Method

1976 ◽  
Vol 25 (12) ◽  
pp. 863-865
Author(s):  
Manabu FUJITA ◽  
Kazuaki SUZUKI ◽  
Shoji MARUZENI ◽  
Yukinobu MURASE
Keyword(s):  
Rapid Method ◽  
Spectrophotometric Method ◽  
Fats And Oils ◽  
Trans Isomers

scholarly journals STUDI OPTIMASI PENENTUAN UNSUR HARA BESI DALAM CAMPURAN TANAH DAN KOMPOS MENGGUNAKAN METODE SPEKTROFOTOMETRI

2015 ◽  
Vol 8 (2) ◽  
pp. 143
Author(s):  
Refilda ◽  
Suhartini ◽  
Indrawati
Keyword(s):  
Citric Acid ◽  
Metal Ions ◽  
Spectrophotometric Method ◽  
Incubation Time ◽  
Iron Content ◽  
Nutrient Content ◽  
Reducing Agent ◽  
Regression Equation ◽  
Complex Stability

Determination of iron nutrient content in a mixture of soil and compost with spectrophotometric method has been carried out. Metal ions Fe(II) complexed with 0.1% ortho-fenantrolin 2 mL, 0.01 M citric acid as reducing  agent  using acetat buffer at pH 4.5 and its complex was measured by using spectrophotometer UV/Vis at wavelength 515 nm, the complex stability for was 60 minutes . The highest nutrient of iron with content in soil:compost with ratio of 0.8:0.2 was 0.92% at incubation time 30 days. The lowest iron content in the mixture of soil:compost (1:0) at incubation time for  15 days was 0.58% that obtained by the regression equation y = 95.85x + 0.025 with R2=0.992. The level of nutrient iron in compost obtained lower than the maximum regulated by SNI 2.00%.

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