Photometric Determination of Chlorides in Water

Abstract

Kith the exception of an occasional determination, the analytical results for the recoveries using calcium or magnesium appear to be eqiially good, regardless of xhether pure calcium and magnesium mixtures alone or other mixtures were analyzed.Figure G s h o w the titrimetric curves obtained at 660 mp for varying concentrations of calcium between 1.25 and 5.0 mey per liter of spinal fluid. The intersection of the tangent to the steep ascending slope of the titration curve to a line parallel to the abscissa and tangent to the upper portion of the cuive indicates the end point.A >imilar study ip shoxn in Figure 7 , where increasing concentrations of concentration of magnesium in the range of 1.05 to 4 20 meq. per liter of spinal fluid are titrated a t 660 mp. The end point is graphically determined in the same manner a.; io1 calciiim. A method has been devised for the photometric determination of small amounts of chloride in water. The method is based on the displacement of thiocyanate f r o m mercuric thiocy-anate by chloride ion and the subsequent reaction of the liberated thiocyanate with ferric iron to form the colored complex [Fe(SCN)] ++, which is measured either visually or in a spectrophotometer. Concentrations of chloride as low as 0.05 p.p.m. can be determined. HE literature on the determination of chloridesisvoluminous.T \Yhether present as a required constitumt or as an impuiity, the chloride ion is usually determined by either gravimetric or volumetric methods. The oldest and the classical method is the gravimetric, in which the chloride ion is evaluated as silver chloride. ..inother method frequently employed is the volumetiic, several variations of which are available. The Volhard method, oiiginated by Carpentier ( 7 ) , described by T'olhard (38), and later improved by Lundbak (65) and others (26), is more accurate than the Mohr method ( 2 7 ) .A comparatively recent method is the mercurometric method, which was developed in 1933 by Dubskj. and Trtilek (9, 10).Diphenplcarbohydrazide v a s used as an indicator in the titration n-ith mercuric nitrate. Other 13-orkers (1, 5 , 8, 20, 62, 29,32, 54) later adopted this method with some modifications. ill1 these methods, homeever, are not always suitable for the detei mination of micro quantities of chloride.The present investigation was the result of a need for a simple colorimetric method for the determination of less than microgram quantities of chloride in condensate. Luce, Denice, and ilkerlund ( 6 4 ) determined small amounts of chloride turbidimet-1 ically. This method, however, lacked the required precision.Other methods (2, 4, 6, 14, 15, 17, 81, 28, 55, S9) for the determination of small amounts of chloride either required special apparatus or lacked the desired simplicity.The method presented here is a modification of that proposed b! . Vtsumi (36, 37) and followed up by Imasaki (16). This modified procedure has been greatly improved and broadened in ita application. The use of ferric perchlorate instead of ferric ammonium sulfate eliminates a ...

Net ion fluxes and ammonia excretion during transport of Rhamdia quelen juveniles

“…Levels of total alkalinity and nitrite were determined as described by BOYD (1998). Chloride levels were determined according to ZALL et al (1956), and Na + and K + levels were determined with a B262 flame spectrophotometer (Micronal, São Paulo, Brazil). Standard solutions were made with analytical-grade reagents (Vetec or Merck) dissolved in deionized water, and standard curves of each ion to be tested were made for five different concentrations.…”

Biochar and Compost Increase Crop Yields but the Effect is Short Term on Sandplain Soils of Western Australia

“…Boron, Cu, Zn, Mn, Fe, Ca, Mg, Na, K, P and S were mea -TABLE I 3 sured by inductively coupled plasma optical emission spectrometry (McQuaker et al, 1979). Nitrate (N0 3 ), and ammonium (NH 4 ) were measured calorimetrically using a flow injection analyser (Zall et al, 1956). Total N was measured using a combustion furnace (Bremner and Mulvaney, 1982) Phosphorus uptake (kg P ha~1 ) was calculated by multiplying total biomass (kg ha~l) at anthesis by the P concentration in the dry sample.…”

Growth of silver catfish ( Rhamdia quelen ) exposed to acidic pH at different humic acid levels

“…Un-ionized ammonia (NH 3 ) levels were calculated according to COLT (2002). Levels of Ca 2+ , Na + and K + were determined with photometer Micronal B286 and Cl -as outlined in ZALL et al (1956). Nitrite was analyzed by spectrophotometry (BOYD & TUCKER 1992).…”