Method For Determination Of Sulfate Research Articles

Determination of Substitution Patterns of Galactans from Green Seaweeds of the Bryopsidales.

Sulfated and pyruvylated galactans are the major soluble polysaccharides produced by seaweeds of the Bryopsidales. Their backbones have a complex and variable pattern of substitution which, until now, has only been elucidated for a few species. Methods for determination of sulfate and pyruvic acid content, and chemical strategies to determine their position in the galactan chain are outlined here. These methods can also be applied to other sulfated and/or pyruvylated polysaccharides.

Use of Barium Chloranilate Solid-Phase Reactor for the Determination of Sulfate in Natural Water Samples Exploiting Long Pathlength Spectrophotometry and Multicommutation

A flow-injection method for the spectrophotometric determination of sulfate in natural water samples using a solid-phase reactor with barium chloranilate (BaC6Cl2O4) immobilized in a polyester resin is presented. This procedure is based on the formation of insoluble barium sulfate (BaSO4) in the solid-phase reactor releasing chloranilate ions (C6Cl2 ), which was monitored spectrophotometrically at a wavelength of 533 nm. The analytical curve was linear in the sulfate concentration range from 2.5 to 40.0 mg L−1 with a detection limit of 0.1 mg L−1 and an analytical frequency of 50 h−1.

Sulfate determination in lagoon water (venice) by reversed-phase ion-interaction chromatography ? a method validation

The validation of a new ion-interaction chromatographic method for sulfate determination is presented by the comparison with results obtained by ionchromatography. The two procedures were employed to quantify sulfate in model solutions and in samples of Venice lagoon water. The statistical t-test for multiple samples showed no significant difference between the two methods, at the 99% confidence level.

Comparison of some methods for determination of sulfate in soils

Abstract Sulfate (SO4 2‐) is present in soils as salts of various metals, and the different metals associated with sulfate may influence adsorption of SO4 2‐by soils. The analytical method used for determination of SO4 2‐could be affected by the type of metal associated with the SO4 2‐. Four analytical methods based on different principles were evaluated for determination of SO4 2‐in different metal salts and in soil extracts obtained with three extractants {0.1M lithium chloride (LiCl), 0.15% calcium chloride (CaCl2), and 500 mg P/L as calcium phosphate [Ca(H2PO4)2]}. The analytical methods were: (i) a methylene blue (MB) colorimetric method after the reduction of SO4 2‐to hyrogen sulfide (H2S), (ii) an ion Chromatographie (IC) method, (iii) a turbidimetric (TD) method, and (iv) an indirect barium (Ba) atomic absorption spectrophotometric (SP) method. The recovery of SO4 2‐associated with various mono‐, di‐, and tri‐valent metals was quantitative by the MB method. But, trivalent metals, such as aluminum ...

Sampling and analysis of rain: methods and results of the Venice regional network

Air quality and in particular acid rain composition has gained a great importance in the recent years all over the world. A vast research program has been undertaken also in the Venice Region. A network of 8 sampling stations, remote from motor traffic and industrial sources of air pollutants, was realized in 1988 according to the EMEP statements. It gives meteorological and physical data on the air quality and produces the wet-only samples of meteorological precipitations, of which the chemical composition is determined in laboratory. An automatic analyzer based on colorimetric methods is used for ammonium, sulfate, nitrate, phosphate and chloride determination and an Atomic Absorption spectrometer for Ca, Mg, K and Na analysis. The methods used are based on those recommended by U.S. Standard Methods for water samples. From all of them the method for sulfate determination needed the most serious modifications, due to the interferences of cations. This paper describes the analytical methods used and their detection limits. Data on the rain quality of the region, in the period February–June 1989 for the first 6 stations installed are reported together with their statistical elaborations. The relationships between single ions and the total amount of ions allow to interpret the rain water composition and to check the validity of the analytical methods. The average rain composition approximates a H2SO4/HNO3 mixture with a volume-weighted average of pH of 5.42 and SO 4 2− /NO 3 − molar ratio of 1.10.

Rapid method for the spectrophotometric determination of sulphate in surface water using ion-exchange separation and the sulphate and chlorophosphonazo III (CPA III)-Ba2+ complex reaction

A rapid spectrophotometric method for the determination of SO 4 2− in surface water is reported. It is based on the reaction of CPA III-Ba2+ complex with SO 4 2− in acidic medium in the presence of ethanol. Beer's law is obeyed up to 120 Μg of SO 4 2− in 25 ml solution. The molar absorptivity is 6.3×103 l · mol−1 · cm−1 at 500 nm, and the coefficient of variation varies from 1.85% to 3.10%. The absorbance remains stable for at least 24 h and interfering ions are separated by strongly acidic cation-exchange resin.

Flow injection and photometric determination of sulfate in rainwater with methylthymol blue

The automated methylthymol blue method for determination of sulfate has been adapted to flow injection sample processing. Prominent features of the method include a linear calibration curve up to 6 mg/L, approximate sensitivity of 0.1 mg/L, and sampling rate of 20 per hour. Average precision was 4.1% and average accuracy evaluated by comparison of results with those obtained by ion chromatography was 97%.

New turbidimetric method for determination of sulphate

Sulphate in the range (1–5) × 10 −5 M is determined by addition of 30–40 mesh lead nitrate crystals (0.2g) to 25 ml of sample solution containing 40–80% ethanol.

A Rapid Method for Determination of Sulfate in Water Samples

Abstract A simple and precise turbidimetric method of determining sulfate S in water samples is described. It involves measurement of the turbidity formed when an aliquot of a barium chloride-gelatin reagent is added to an acidified sample. The method is sensitive and accurate and permits determination of microgram amounts of sulfate S present in water samples.

Electrophoresis of acidic glycosaminoglycans in hydrochloric acid: A micro method for sulfate determination

A rapid and simple method for estimation of the sulfate content of less than 1 μg of acidic glycosaminoglycans is presented. The procedure is based on the fact that the electrophoretic mobility in 0.1 M hydrochloric acid is proportional to the sulfate content of the polysaccharide.

Analytical applications of sodium lauryl sulphate II.—The volumetric determination of sulphates

AbstractThe literature on the ethylenediaminetetra‐acetate method for determination of sulphate is reviewed and the limitations of the method are discussed. In the procedure now described, after precipitation of sulphate as barium sulphate, excess barium is precipitated with sodium lauryl sulphate and excess of the latter titrated with a suitable quaternary ammonium salt as described in Part I of this series.

New volumetric method for determination of sulfate

New volumetric method for determination of sulfate