A modification to Schoonover's method of gypsum requirement determination of soil

Soil Research ◽  
1979 ◽  
Vol 17 (2) ◽  
pp. 367 ◽  
Author(s):  
RPS Chauhan ◽  
CPS Chauhan

During laboratory studies it was noted that water-soluble carbonate plus bicarbonate interferes with the determination of gypsum requirement (GR) by Schoonover's method and has significant correlation with the latter (r = 0.89). The interference of carbonate and bicarbonate can be eliminated through their precipitation as magnesium carbonate. A modified method to this effect is suggested hereby, and values of GR determined by this method are quite close (r = 0.99) to those of exchangeable sodium and give a fair approximation to it.

2020 ◽  
Vol 1 (12) ◽  
pp. 112-118
Author(s):  
O. A. Voronina ◽  
◽  
A. A. Savina ◽  
N. S. Kolesnik ◽  
N. V. Bogolyubova ◽  
...  

The influence of fattening conditions on the digestive and metabolic processes in animals is actively studied to increase the production of animal food. The aim of the study was to estimate the total amount of water-soluble antioxidants in the blood serum of Duroc boars depending on the duration of fattening. Experiments were conducted on 102 animals to confirm the results of laboratory studies, as well as determination of the total antioxidant activity of pig blood serum by amperometric method. For the first time, a significant difference in antioxidant activity was found in blood samples of Duroc boars with the duration of their fattening from 81 to 101 days.


1984 ◽  
Vol 67 (5) ◽  
pp. 863-865 ◽  
Author(s):  
Gerald L Stahl ◽  
Dal D Kratzer

Abstract An AOAC modified method is described for the microbiological assay of neomycin, which has been adapted to include complete feeds, supplements, premixes, liquids, oil suspensions, boluses, and antibiotic-impregnated paper. The method features a more sensitive standard response line with a monolayer plating system. The use of a buffered plating medium in place of the water-prepared medium results in a curve with less degree of slope, which allows for more accurate interpretation of the standard response. The feed extract diluent used for standard response line dilution, which is prepared from exposure of the feed extract fluid to pH changes, heat, and sodium hypochlorite, has been eliminated. The constant salt concentration diluent used for the preparation of standards is the same as the salt concentration of the sample extract solution to be tested. Results for 50 commercial complete feeds and 50 commercial premixes received over the last 5 years produced an overall mean recovery of 101% with a mean percent recovery range of 80-112%. A statistical analysis of these 100 commercial, complete feeds and premixes, ranging in concentration from 47 g/ton to 70 g/lb, indicates the assay has little, if any, concentration-related bias. Precision and accuracy of the method was supported by laboratory studies of 20 assays that produced a mean recovery of 101 % and standard deviation of 3.


1958 ◽  
Vol 38 (1) ◽  
pp. 27-35 ◽  
Author(s):  
R. F. Bishop ◽  
R. L. Cook

Greenhouse and laboratory experiments were used to study the effect of various soil amendments on the water-soluble boron content of a strongly acid soil.In the greenhouse, using ladino clover as the test crop, liming reduced boron availability as measured by soil and plant analysis. Calcium-boron ratios in the clover ranged from approximately 550:1 to 2000:1 and there was a significant correlation between the water-soluble boron in the soil and the boron content of the clover.In the laboratory studies calcium and magnesium carbonates were equally effective in decreasing water-soluble boron in soil. Gypsum was ineffective. Manure or alfalfa hay increased the water-soluble boron content of soil in proportion to the amounts applied. Applications of sodium hydroxide, resulting in a range of soil pH values from 4.82 to 9.72, were accompanied by decreases in water-soluble boron until a pH of approximately 8.0 was reached. Above this point water-soluble boron increased. At comparable pH values of approximately 7.0 or less, sodium hydroxide caused a smaller reduction in water-soluble boron than did either calcium or magnesium carbonate.


Author(s):  
Hind Hadi ◽  
Gufran Salim

A simple, rapid and sensitive spectrophotmetric method for trace determination of salbutamol (SAL) in aqueous solution and in pharmaceutical preparations is described. The method is based on the diazotization coupling reaction of the intended compound with 4-amino benzoic acid (ABA) in alkaline medium to form an intense orange, water soluble dye that is stable and shows maximum absorption at 410 nm. A graph of absorbance versus concentration indicates that Beer’s law is obeyed over the concentration range of 0.5-30 ppm, with a molar absorbtivity 3.76×104 L.mol-1 .cm-1 depending on the concentration of SAL. The optimum conditions and stability of the colored product have been investigated and the method was applied successfully to the determination of SAL in dosage forms.


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