Colorimetric Determination of Trace Quantities of Boric Acid in Biological Materials

Smith, W. C.; Goudie, Alexander J.; Sivertson, J.N.

doi:10.1021/ac60098a036

Cited by 31 publications

(2 citation statements)

References 11 publications

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“…The curves presented in Figure 1 were obtained using Baker reagent grade sulfuric acid. This was in accordance with the statement by Smith, Goudie, and Sievertson (6), that this acid was apparently free of boron and satisfactory for the purpose. Subsequent information from Powell indicated the contrary.…”

Section: Procedures and Color Measurementssupporting

confidence: 92%

Carminic Acid Procedure for Determination of Boron

Callicoat¹,

Wolszon²

1959

Anal. Chem.

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Carminic acid reagent has been used by several authors for the colorimetric determination of boron. Discrepancies among procedures and lack of reproducibility have led to a reevaluation of the factors affecting sensitivity and precision: reagents, concentrations, and their relationship to development time and sensitivity, as well as laboratoryware and procedures for evaporation of aqueous samples prior to colorimetric analysis.The procedure proposed has shown accuracy and precision to ± 0.3 y of boron over the range of 0 to 40 7 of boron.

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Section: Procedures and Color Measurementssupporting

confidence: 92%

Carminic Acid Procedure for Determination of Boron

Callicoat¹,

Wolszon²

1959

Anal. Chem.

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“…Lactose concentration was determined spectrophotometrically (486 nm) by the phenol sulfuric acid method [28]. The Boric acid concentration was determined spectrophotometrically (585 nm) by the carminic acid method [29]. Phosphate concentration was determined spectrophotometrically (880 nm) by the molybdenum blue method [30].…”

Section: Determination Methods Of Lactose Boric Acid Phosphate and Pr...mentioning

confidence: 99%

Adsorption of Lactose Using Anion Exchange Resin by Adding Boric Acid from Milk Whey

Maruyama,

Seki

2023

Separations

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The influence of adding boric acid (BA) on the adsorption behavior of lactose onto an anion exchange resin (IRA402) was investigated. By adding BA, the amount of lactose adsorbed onto IRA402 was increased ca. 20% compared to without adding BA. In the presence of BA, ca. 70% of the adsorbed lactose could desorb from IRA402, while the absorbed lactose hardly desorbed in the absence of BA. Lactose molecules were considered to bind to tertiary amine group on IRA402 by Maillard reaction. The optimum conditions of the dosage of BA and pH were found at the molar ratio of BA to lactose ranging from 1–2, and pH 7–9. The kinetics and equilibrium of lactose adsorption could be explained by the Langmuir adsorption model (best model). In the case of a real whey solution, phosphate strongly affected the adsorption behavior and could be removed as precipitation from the whey over pH 10. Whey proteins had little effect on lactose adsorption, which was ca. 30% less than that in the model system. Moreover, the different kinds of whey proteins and amino acids had little effect on the amount adsorbed. Minerals in the whey may also be considered to be responsible for the decreased adsorption in the whey.

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Borate complexes of amphotericin B: Polymeric species and aggregates in aqueous solutions

Strauss

Kral

1982

Biopolymers

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SynopsisAmphotericin B, a polyene macrolide antibiotic, exists in aqueous solution as a poorly soluble, high-molecular-weight aggregate. A borate complex of this polyene was prepared that has greater solubility and is less aggregated. In aqueous solution this borate complex exists as a mixture of several molecular species differing in borate content, molecular weight, and molecular conformation. The solubility varied with pH and was minimal at neutrality.Throughout the pH range it was one to two orders of magnitude higher than that of the parent compound. The molecular size distribution, as determined by differential ultrafiltration, showed a progressive increase in the weight fraction of aggregates going from acid to alkaline solutions. The sizes of aggregates ranged from under 25 to over 100 molecules. The borate content of the complexes increased with increasing pH. No borate was complexed in acid solutions. This indicated that amphotericin B and borate ions can complex to form copolymer chains of varying length in which these species alternate, since both are bifunctional. The complexation equilibrium is favored by high pH. Absorption and CD spectra indicated that the polyene molecules can stack reversibly to form dimers. Dimerization constants calculated from the spectra were highest in neutral solution and declined with increasing acidity or alkalinity. In alkaline solutions the polymer chains are long and extended, with minimal stacking. In neutral solution the chains are shorter and extensively stacked. In acid solutions no borate complexes are formed, and the polyenes are stacked to an intermediate degree. The very different effects of pH and concentration on the degree of complexation with borate and on the degree of dimerization of the polyenes shows that these equilibria are independent of each other.

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Colorimetric Determination of Trace Quantities of Boric Acid in Biological Materials

Cited by 31 publications

References 11 publications

Carminic Acid Procedure for Determination of Boron

Carminic Acid Procedure for Determination of Boron

Adsorption of Lactose Using Anion Exchange Resin by Adding Boric Acid from Milk Whey

Borate complexes of amphotericin B: Polymeric species and aggregates in aqueous solutions

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