The determination of hot‐water‐soluble boron in some acid Oregon soils using a modified azomethine‐H procedure

1981 ◽  
Vol 12 (12) ◽  
pp. 1311-1322 ◽  
Author(s):  
D.R. Parker ◽  
E.H. Gardner
Keyword(s):  
Water Soluble ◽  
Hot Water

Contributions to the Analysis of Rubber. I. Determination of the Water-Soluble Components of Rubber

1937 ◽  
Vol 10 (3) ◽  
pp. 574-583
Author(s):  
P. Dekker
Keyword(s):  
Acetic Acid ◽  
Acid Reflux ◽  
Water Soluble ◽  
Hot Water ◽  
Water Bath ◽  
Vulcanized Rubber ◽  
Magnesium Compounds ◽  
Calcium Compounds ◽  
Soluble Components

Abstract 1. It is shown that the methods which are ordinarily used for determining water-soluble substances in raw rubber give low results, and are quite useless for vulcanized rubber. 2. New analytical procedures are developed for determining the water-soluble substances in raw rubber and in vulcanized rubber. These procedures are carried out in the following manner. (a) Raw Rubber.—Heat 2 grams of rubber in 80 cc. of xylene and 5 cc. of acetic acid on a water bath until the rubber is completely dissolved, add 5 cc. of acetic acid and 10 cc. of water, heat for 3–4 hours on the water bath with frequent agitation, transfer to a distilling flask (rinsing the first flask with 50 cc. of hot water), distill the xylene with steam, filter the residual solution, evaporate the filtrate on a water bath; and dry at 100° C. (b) Vulcanized Rubber and Rubber Mixtures.—First extract the sample with acetone, heat 2 grams of the acetone-extracted sample with 80 cc. of xylene on a water bath, add 5 cc. of acetic acid, reflux the mixture on an oil bath, after complete dissolution add 5 cc. of acetic acid and 10 cc. of water, heat the solution for 2 hours on an oil bath at 110–120° C., distill the xylene, as in the determination with raw rubber, filter the residue, evaporate the filtrate to dryness, take up the residue in 50 cc. of water, pass a current of hydrogen sulfide through the solution for 10 minutes to precipitate zinc as sulfide, filter, evaporate the filtrate, and dry the residue at 100° C. 3. In the presence of calcium compounds, magnesium compounds, glue and textiles, the method gives false results. Modifications of the method are therefore recommended, whereby these substances are eliminated.

SOME FACTORS AFFECTING THE DETERMINATION OF HOT-WATER-SOLUBLE BORON FROM PODZOL SOILS USING AZOMETHINE-H

1979 ◽  
Vol 59 (3) ◽  
pp. 241-247 ◽  
Author(s):  
UMESH C. GUPTA
Keyword(s):  
Prince Edward Island ◽  
Sandy Loam ◽  
Water Soluble ◽  
Hot Water ◽  
Colorimetric Determination ◽  
Factors Affecting ◽  
Water Extracts ◽  
Percent Recovery

A study was conducted on some factors affecting the colorimetric determination of B using the azomethine-H reagent on soils from Prince Edward Island. Two fine sandy loam soils (A and B) were used for the main study and additional soil samples varying in organic matter (OM) were used to assess the role of OM. Soils containing less than 3.0% OM and 3.1–4.1% OM required 0.4 g and 0.8 g charcoal per 25 g soil, respectively, to produce clear hot-water extracts. Quantities of greater than 0.8 g charcoal were necessary to produce clear extracts from soils containing more than 4.1% OM. Colored hot-water extracts of soil resulted in higher absorbance than those hot-water extracts treated with charcoal as measured at 430 mμ. Additions of 0.8 and 1.6 g charcoal or greater to the soils (A and B) resulted in considerably lower recoveries of B as noted by comparing the absorbance obtained using 0.4 and 0.8 g, respectively. Storage of azomethine-H up to 7 days did not affect the absorbance of the B-azomethine-H complex. One hour after the addition of azomethine-H, a maximum absorbance was found which persisted for up to 4 h. The percent recovery of B added to the two soils was about 10–12% less using azomethine-H as compared to those obtained using the carmine method. However, the mean hot-water-soluble B contents of 10 soils as measured using the carmine and azomethine-H reagents were 0.70 and 0.66 ppm. Pure B solutions when boiled with charcoal resulted in losses of B added. Such losses of B increased with increasing rates of charcoal.

AN ANALYSIS OF AVENA COLEOPTILE PECTIN FRACTIONS

1965 ◽  
Vol 43 (9) ◽  
pp. 1083-1095 ◽  
Author(s):  
D. James Morré ◽  
Alfred C. Olson
Keyword(s):  
Cell Wall ◽  
Galacturonic Acid ◽  
Water Soluble ◽  
Hot Water ◽  
Plant Tissues ◽  
Cytoplasmic Fraction ◽  
Avena Coleoptile ◽  
Heat Stable ◽  
Heat Stable Protein

Extraction and determination of pectic materials from growing plant tissues is often complicated by overlapping solubilities and lack of specificity of the pectin assay utilized. We find that the hot water soluble, hot versene soluble, and residual uronide components of Avena coleoptile cell wall represent at least three distinct pectin fractions with little or no overlap in solubility. In situations where hexose interference in colorimetric pectin determinations became appreciable, the polyanhydrogalacturonic acid content of the extract was determined by measurement of isolated galacturonic acid released through the specific action of polygalacturonase.A fourth fraction containing pectin-like materials was extracted from whole tissue in cold acetate buffer. This fraction was associated with heat-stable protein. No pectin identified as polyanhydrogalacturonic acid was found in the cytoplasmic fraction by the same techniques used for identifying pectin on cell wall derived fractions.

Simultaneous Spectrophotometric Determination of Salbutamol by Coupling with Diazotized 4-Aminobenzoic acid

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Hind Hadi ◽  
Gufran Salim
Keyword(s):  
Pharmaceutical Preparations ◽  
Coupling Reaction ◽  
Dosage Forms ◽  
Water Soluble ◽  
Trace Determination ◽  
Aminobenzoic Acid ◽  
Optimum Conditions ◽  
Colored Product ◽  
Versus Concentration

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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