An improved method for the determination of nitrogen in plant material using a stable nessler reagent

1962 ◽  
Vol 13 (12) ◽  
pp. 669-672 ◽  
Author(s):  
D. G. Hill-Cottingham ◽  
Susan A. Wagner
Keyword(s):  
Plant Material ◽  
Improved Method ◽  
Nessler Reagent

SERUM TRIIODOTHYRONINE DETERMINATION BY SATURATION ANALYSIS

1973 ◽  
Vol 72 (4) ◽  
pp. 714-726 ◽  
Author(s):  
A. Burger ◽  
B. Miller ◽  
C. Sakoloff ◽  
M. B. Vallotton
Keyword(s):  
Ionic Strength ◽  
Limit Of Detection ◽  
Improved Method ◽  
Accuracy Of Measurement ◽  
Tracer Amount ◽  
The Mean ◽  
Physiological Values ◽  
Hyperthyroid Patients ◽  
Solvent Blank

ABSTRACT An improved method for the determination of serum triiodothyronine (T3) has been developed. After addition of a tracer amount of the hormone, T3 was extracted from 1 ml serum under conditions of pH and ionic strength which favoured T3 extraction (89%) over thyroxine (T4) extraction (58%). Chromatography of the extracted material on Sephadex LH-20 separated T3 completely from residual T4. The T3 eluate was dried, then re-dissolved in 0.5 ml NaOH 0.04 n. To 0.2 ml duplicate aliquots, a standard amount of TBG was added for the competitive protein analysis. After one hour incubation at 4°C, separation of bound from free T3 was achieved on small Sephadex G-25 columns. Overall recovery was 67 ± 10.8% and correction for the loss was made. The solvent blank was 37 ± 27 (sd) ng/100 ml. Accuracy of measurement of known quantities of T3 added to serum was 98.4%. The coefficient of variation within the assay was 6.2% and between the assays it was 11.4%. The limit of detection (0.1 ng) corresponded to a concentration of 25 ng/100 ml. T4 added to serum did not interfere with T3 determination until high non-physiological values were reached. The mean ± sd serum T3 in 54 euthyroid subjects was 153 ± 58 ng/100 ml and in 24 hyperthyroid patients it was 428 ±186 ng/100 ml; 4 out of the 24 hyperthyroid values were within 2 sd of the mean euthyroid group. All the values found in the euthyroid group were well above the limit of detection of the method.

An Improved Method for the Determination of Metabolic Fecal P

1957 ◽  
Vol 16 (1) ◽  
pp. 201-206 ◽  
Author(s):  
J. R. Luick ◽  
G. P. Lofgreen
Keyword(s):  
Improved Method

Contribution to the Optimization of a Gas Chromatographic Method by QbD Approach used for Analysis of Essential Oils from Salvia officinalis

2019 ◽  
Vol 70 (6) ◽  
pp. 2015-2020
Author(s):  
Silvia Robu ◽  
Aurelia Romila ◽  
Olimpia Dumitriu Buzia ◽  
Adrian Florin Spac ◽  
Camelia Diaconu ◽  
...  
Keyword(s):  
Essential Oil ◽  
Essential Oils ◽  
Plant Material ◽  
Mobile Phase ◽  
Chromatographic Method ◽  
Salvia Officinalis ◽  
Salvia Officinalis L ◽  
Gas Chromatographic Method

Numerous articles on Salvia officinalis L. have been published regarding the composition of their essential oil. The considerable variation found may be due to the quality of the plant material as well as to the methods used for analysis. A simple GC-MS method was developed and optimized in the QbD approach, for the determination of sage essential oils. The optimization of GC-MS analysis was performed using different mobile phase flows, injection volumes, split ratios and temperature programs. The optimized method proved to be simple and can be successfully applied for the determination of sage essential oils.

scholarly journals THE COLORIMETRIC DETERMINATION OF FRUCTOSAN IN PLANT MATERIAL

1945 ◽  
Vol 157 (1) ◽  
pp. 161-167
Author(s):  
Willard L. McRary ◽  
Marion C. Slattery
Keyword(s):  
Plant Material ◽  
Colorimetric Determination

Improved Method for the Determination of Ethylenebisdithiocarbamate Residues in Plants, Fruits, and Vegetables

1967 ◽  
Vol 50 (5) ◽  
pp. 1102-1108
Author(s):  
Charles F Gordon ◽  
Richard J Schuckert ◽  
William E Bornak
Keyword(s):  
Sulfuric Acid ◽  
Fruits And Vegetables ◽  
Analytical Procedure ◽  
Improved Method ◽  
Modified Method ◽  
Fungicide Residues ◽  
Crop Types ◽  
Large Representative

Abstract A modified method for the determination of dithiocarbamate fungicide residues on crops is presented. A large representative subsample of the frozen crop is blended in ice-cold deaerated water and an aliquot of the homogenate is added to the analytical apparatus containing hot 5 0% sulfuric acid. Dithiocarbamates are decomposed to evolve CS2 which is removed by a continuous gentle air-sweep from the digestion flask. Variations in technique allow the analysis of dithiocarbamate fungicide residues in several ranges, 1-10, 10-200, and 200-1000 /ig maneb. Recoveries from a wide variety of crops averaged 70 to 103%. Certain crop types present low recoveries and/or high apparent control values, but modifications in the analytical procedure are successful in solving these problems.

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