Analysis of Chlorides

Abstract

A new electrometric end point for the titration of chlorides with silver nitrate is detected by the potential between a silver wire and a copper wire in a solution of copper sulfate containing the unknown chloride. A simple potentiometer and a microammeter are the only electrical equipment necessary.The errors are of the order of 0.2%. Of 44 ions tested for possible interference, 30 introduce no error.

Inorganic Volumetric Analysis

“…Further work on the use of high frequency oscillators (87), which at one time promised to revolutionize volumetric analysis, has not been found. A simple apparatus, requiring only a battery, a microammeter, a variable resistance, and silver and copper wires for electrodes has been used with good results for the rapid analysis of chloride (49). Apparatus for polarization dead-stop end points has been described (58) which is essentially that of earlier workers (65).…”

“…Halides and Halates. Determination of hydrochloric acid in presence of chlorine by boiling to remove chlorine and titrating hydrochloric acid with alkali (12); chloride by amperometric method (81), conductometric (4), and potentiometric (49) titration with indicator by extracting color into ether (76), modification of Berg's method (213); interesting method by reaction of soluble chlorides with solid mercurous iodate and, after filtering, by iodometric titration of precipitate with thiosulfate (7); chloride after adding thiocyanate and ferric nitrate, titrating with mercuric nitrate (154); chlorates by titrating with methyl orange solution (41), iodometric (220), ferrous sulfate reduction (219), or Volhard method after bomb reduction (184); reaction of hypochlorite with hydrazine sulfate, which is then back-titrated with hypochlorite solution (36); chlorate and hypochlorite with sodium benzene sulfinate (6); hypochlorite and hypobromite based on selective reduction of hypobromite with alkaline phenol (60); iodide by automatic titration (118) and by thiosulfate at controlled pH (5).…”

Fertilizers

“…Recent study (160) of the time-honored Mohr procedure, which is the official method for chlorine in fertilizers (14, p. 34), leads to the conclusion that the titration is accurate in acidic solutions down to pH 4 if a correction is applied for the indicator blank. For solutions that are acid to methyl red, titration at pH 4.7 in the presence of a sodium acetate-acetic acid buffer is recommended Potentiometric titration of the chloride ion with silver nitrate has been investigated by several workers (63,64,190,297,298). The method proposed by Dean and Hawley (63) eliminates the use of a salt bridge, and avoids interference by a number of the ions commonly present in fertilizer solutions.…”

Hollow‐fiber liquid‐phase microextraction for the determination of pesticides and metabolites in soils and water samples using HPLC and fluorescence detection

“…In this sense, sample pretreatment is a critical step that must be selective and sensitive enough, especially in the case of soils. Having a look at the literature, pesticides and related compounds have been classically extracted from soils using solid-liquid extraction (SLE) procedures [2,3], including Sohxlet extraction, pressurized liquid extraction (PLE), supercritical fluid extraction (SFE), microwave-assisted extraction (MAE), etc. After this, the soil extract must be cleaned up, at the same time that an important preconcentration must occur.…”