Sulphates determination

The precision of the determination increases in mixed solvents, for example 70% ethanol [119] or dioxan/water [340]. A special ISE with a membrane consisting of a PbS, PbS04, Ag2 S and CuS mixture has been constructed for sulphate determinations [320]. 

Coutinho, J. (1997) Automated method for sulphate determination in soil-plant extracts and waters. In Hood, T.M. and Benton Jones, J., Jr (eds) Soil and Plant Analysis in Sustainable Agriculture and Environment. Marcel Dekker, New York, pp. 481 94. 

Politi L, Chiaraluce R, Consalvi V, Cerulli N, Scandurra R (1989) Oxalate, phosphate and sulphate determination in serum and urine by ion chromatography. Clin Chim Acta 184 155-165... 

When recrystallizing sulphates, determine the presence of an impurity formed by a chloride ion. 

This innovation generally involves modifications to the operation of the sampler and random access reagent selection, and can be implemented in both segmented and unsegmented flow analysers. For unsegmented flow analysis, the spectrophotometric determination of zinc and phosphate in soil extracts [368] is a good example. Zinc was determined only when phosphate was present at concentrations above a threshold level. The number of determinations required was reduced by 30%. Analogously, an expert flow system was proposed for the turbidimetric determination of chloride and sulphate in natural waters [369]. Both methods were implemented in the same manifold, and the need for sulphate determination was dependent on the chloride concentration determined. 

Table V-26 Experimental values for the first association constant of nickel sulphate determined in the presence of supporting electrolytes (see Appendix A). Values of log IQ K° were determined using the SIT (Appendix B).

Table V-26 Experimental values for the llrst association constant of nickel sulphate determined in the presence...

P. Langer, Investigations for Sulphate Determination in Natural Waters by Means of Flow Injection Analysis [in German]. Tech. Univ. Berlin, Germany (1983). (M.Sc. Thesis). 

Such low-permeable layers can be formed not only on account of high-molecular surfactants. It has been shown in [29] that the adsorption layer permeability of proteins (bovine serum albumin, gamma-globulin) and lauiyl sulphate, determined by loss in weight of the evaporating film, is practically the same. Addition of higher alcohols to alkyl sulphates enhances the foam stability under dry air conditions. When lauryl alcohol was added to dodecyl sulphate, it turned out that the life time of the foam increased by 10 to 20 % at reduced air humidity. Note that this effect is more pronounced at maximum undersaturation of air by water vapours. 

Precipitation was very frequently used in the past as a method of determining certain substances in water by direct gravimetric analysis. Even today, for example for sulphate determination, precipitation from an acidified... 

Sulphur is determined by either the Schoeniger test, in which a sample is burnt in oxygen, or by one of a number of fusion methods in which a sample is ignited with an alkaline mixture. In the former, the combustion products are absorbed in alkali. In the latter, the melt is dissolved in water. In both cases the solution is acidified and the sulphate determined by precipitation as BaS04. The method given here is a fusion method. 

Any sulphate with a-sulphonated fatty ester. BEC titration in alkaline solution after acid hydrolysis gives twice the a-sulphonated ester (approximately—see above) plus any sulphonated hydrocarbon, less the sulphate. Determine the sulphate separately by measuring any one of its decomposition products. 

W.R. Melchert, F.R.R. Rocha, An improved procedure for flow-based turbidimetric sulphate determination based on a liquid core waveguide and pulsed flow. Anal. Chim. Acta 616 (2008) 56-62. 

Dissolve about 01 g in 25 ml of water, add 25 ml of glacial acetic acid and 25 ml of dilute hydrochloric acid and titrate with 0-02N ceric ammonium sulphate, determining the end-point potentiometrically using a platinum/calomel electrode system. 1 ml 0-02N = 0 004221 g... 

Alkyl benzene sulphate, determination of 439 Alkyl phosphates, determination of 292, 293... 

Sodium-N-diethyldithiocarbamate, determination of 207 Stilbenzene, determination of 263, 264 Substituted urea herbicides, determination of 314-316 Succinate, determination of 60-65 Sulphate, determination of 51-56, 60-65, 70-75, 77, 87-90,170,199,... 

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