Argentometric methods determination

Argentometric methods were used, as mentioned above, in the determination of thiol compounds. The amperometric determination of mercaptansP > can be carried out as follows. 

Numerous determinations of the same kind as those given here have been recommended in previous pharmacopeias. Generally, they consist of titrating halide ions, once they are formed by mineralization, by an argentometric method. Usually, it is Charpentier-Volhard s method. We can also cite the examples of lindane (y-benzenehexachloride, DTT, iodoform, eosine, chlorotrianisene, etc.). The preliminary mineralization is carried out in alkaline medium, that is, with sodium or... 

Argentometric titration involves the titrimetric determination of an analyte using silver nitrate solution as titrant. Its application in environmental analysis is limited to the determination of chloride and cyanide in aqueous samples. The principle of the method is described below. 

The consumption of cyanide is accurately determined by argentometric titration. The method was found to apply both to oxidized starch [439] as well as to cellulose [418], The method is accurate and recently the coefficient of variance and standard deviation for an oxidized cellulose containing 5.60 mmol per 100 g of ketone groups, were found to be 0.0046 and 0.0068, respectively. The corresponding values for the carboxyl groups by the methylene blue method of the same samples were 0.001 and 0.031 [440]. 

Argentometric titration method has been applied to the determination of sulfonamide mixtures. The sulfonamides are quantitatively precipitated by the addition of excess standard silver nitrate solution, the precipitated silver salts removed by filtration, and the excess silver nitrate titrated with standard ammonium thiocyanate using ferric alum as indicator (32). 

The analyst has little choice in the selection of a redox analytical method. In acid solution ceric ion is the most effective oxidant however, in acid solution there is possibility of analytical error because of the volatility ofhydrazoic acid. In alkaline solution, reduction of the azide ion by homogeneous or heterogeneous reduction methods results in variable stoichiometry and cannot be used. The argentometric determination of azide ion in neutral solution is satisfactory but has one serious drawback the manipulation of silver azide, a high cxplosix c. Two basic approaches have evolved for the assay of azide ion ... 

Several methods can be used for the determination of chloride in water [2], The argentometric and mercuric nitrate methods are based on the titration of chlorine in the presence of an indicator. Experimental procedures are easy, but many substances may interfere with the results. There are also other methods such as potentiometry, capillary electrophoresis and other automated methods (ferricyanide method or flow injection analysis). 

Abstract. Cyanides and hydrocyanic acid are one of the priority pollutants being most toxic. Therefore, it is very important to monitor cyanide concentration with specific and sensitive analytical methods. Some analytical methods for cyanide determination were presented in the last years spectrophotometer, potentiometer with silver cyanide electrode and titrimetric method. The paper presents original results concerning the spectrometric method and argentometric titration utilization for the measurement of cyanide concentration in some distilled alcoholic drinks from plums, grapes and apricots. The obtained cyanide concentrations vary between 0.0162 and 0.0970 mg/lOOmL, being under the imposed limits. 

The argentometric determination involving titration against AgN03 is carried out in neutral or slightly alkaline media (pH 6.5-10.5). The end point is indicated visually with formation of the red-brown precipitate of Ag2Cr04 which is more soluble than the precipitate of AgCl, or po-tentiometrically (silver indication electrode, calomel reference electrode). The method is used for the determination of chlorides at concentrations > 4 mg F [13, 14]. 

The first comment that must be made is to assert that it is a prototropic back fixation with sulfuric acid, and not only an argentometric fittafion, although, in the procedure, a quantitative determination of chloride ions is mentioned. The fixation of chlorine ions with silver ions is used to be sure that an excessive consumption of hydroxide ions does not exist. In fact, it is just this excessive consumption of hydroxide ions that liberates the chloride ions from chloroform. In other words, the consumed hydroxide ions that correspond exactly to the concenXafion of chloral hydrate are those given in the first chemical equation. The second comment is that Mohr s method is particularly well adapted to determine the liberated chloride ions, due to the basic pH of the solution imposed by the use of phenolphthalein as indicator ... 

Zeisel s method is used to determinate methoxy and ethoxy groups. It is a method of both qualitative and quantitative organic analysis. It is mentioned under the heading General Methods of Analysis of the 10th edition of the french pharmacopeia. It ends with an argentometric titration. Its principle is based on the reaction of hydroiodic acid (Berthelot s universal reductor) with ether oxides, according to the reactions... 

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