Dosage Du Mercure Dans Les Eaux Naturelles Non Ou Peu Polluees Apres Extraction Par Le Systems Pyrrolidinedithiocarba -Mate-Carbonate De Propylene

Abstract

A procedure for determination of mineral mercury in soft water and sea water is described for the concentrations in the range 5–500 ng. 1^?1. This method involves formation of the mercury-pyrrolidinedithiocarbamate complex which is extracted by propylene carbonate. The extracted mercury is reduced in this solvent by stannous chloride and quickly entrained by nitrogen. The amount of mercury is determined by atomic absorption spectrophotometry at 253. 7 nm.     

Dosage Des Traces De Detergents Non-Ioniques Dissous Par Spectrophotometrie D' Absorption Atomique

Abstract

A novel procedure for the analysis of non-ionic surfactants is reported. The method relies on extraction of a cobaltithiocyanate adduct from an aqueous sample into a benzene phase. The amount of cobalt extracted was determined by atomic absorption and correlated linearly with the corresponding surfactant concentration in the aqueous specimen. Relevant pollution levels in the Atlantic Ocean were estimated rapidly with a precision and accuracy of 10% or better.     

Etude Des Teneurs En Cuivre,Zinc, Et Arsenic Dans La Poudre De Lait Par Activation Neutronique

Abstract

Copper, zinc and arsenic have been determined in dehydrated milk powder by neutron activation analysis. Irradiation 13 of ashed milk powder in a flux of 10¹³ thermal neutrons per second per sq. cm. was followed by: elution through an anion exchange resin; solvent extraction of copper with dithizone into a chloroform phase; precipitation and subsequent redissolution of arsenic as As₂, S₃ and as a polysulfide, respectively. The determinative step involved gamma ray spectroscopy of the isotopes Zn⁶⁷, Zn⁶⁵, Cu⁶⁴ and As⁷⁶.     

Anionic and Nonionic Detergent Determination by Flameless Atomic Absorption Spectrophotometry

Abstract

Procedures for the determination of anionic and nonionic detergents in natural waters are described. Flameless atomic absorption spectrophotometry enables reduction of the sample volume and of the number of steps in the procedure. Sensitivities are better than 10 μg.1^?1 and relative standard deviations are of the order of 5%.