Cathode-ray-polarography

XX) A.F. Williams D. Kenyon, Explosivstoffe 11, 249(1963) (Application of cathode-ray polarography to analysis of mining explosives)... 

POL—Davis differential cathode ray polarography AA—atomic absorption spectroscopy... 

Confirmation of the identity of the gas chromatographic components has been accomplished by thin layer chromatography, relative retention times on different gas chromatographic columns, "p" values, and most recently by mass spectrometry. Dicofol can be separated from its phenone by using a Florisil column (17) or TLC. Dehydrochlorination of dicofol to DBP can be used as a confirmatory test for the parent compound. Gajan and Lisk (23) used cathode ray polarography to analyze vegetables for dicofol residues. 

Cathode ray polarography has found limited application to trace elements in forage [106] and fruit and vegetables [107]. 

Cathode-ray Polarography Typical applications to metallurgical analysis,... 

ASP, anodic stripping polarography CRP, cathode-ray polarography DME, dropping mercury electrode CSP, cathodic stripping polarography Amp., amperometric end point. 

Cathode-ray polarography has found considerable use in water analysis. Four commercial models are available. Southern Analytical Ltd., manufacturer of one of the commercial instruments, has prepared a series of bulletins describing the determination of some 30 anions or cations in water or related materials. 

Cathode-ray polarography has been very useful in a number of analyses of water used in reactor circulating systems. To determine the extent of contamination from some aluminum and steel containers, aluminum and iron were determined on 25 ml. samples of water after evaporation and ignition to determine the weight of the residue. The residues, weighing about 3 mg. each, were qualitatively identified as chlorides. The residues were dissolved in 5M HCIO4 and sodium acetate to obtain a pH of... 

Cathode-ray polarography has been used to monitor the quahty of the house-supply of distilled water available in the NBS Chemistry Building. In each case, the element that was determined depended on the trace determinations being made in one of the laboratories at that time and would constitute a blank correction. In general, water samples were concentrated 10 to 100-fold and measurements were made in O.IN hydrochloric acid, which permitted simultaneous determination of the elements noted. 

In addition, at least two commercially available antioxidants have been shown by differential cathode-ray polarography to exhibit reduction waves Santonox R gives a poorly shaped wave at -0.6 V in an electrolyte consisting of ammonia and ammonium chloride in methanol-water [98] and 3,5-di-t-butyl-hydroxytoluene gives a wave at -0.65 V in aqueous sodium or lithium hydroxide [99]. In both cases, 40 ppm of analyte gave a current which was adequate for quantitative analysis. 

The procedure of Kuta and Quackenbush [121] can be modified for the determination of relatively simple organic peroxides such as benzoyl peroxide, para-tert-huty perbenzoate and lauroyl peroxide in PS, and would no doubt be suitable for the determination of other types of peroxides. In these procedures a suitable weight of polymer is dissolved in toluene and then an equal volume of 0.6 M lithium chloride in methanol is added. Precipitated polymer is removed by centrifuging and peroxides in the filtrate are determined by cathode-ray polarography. Polymerisation additives, styrene monomer or antioxidants in the polymer do not interfere in the polarographic procedure. A procedure for the determination of down to 20 ppm para-tert-hu.ty perbenzoate in PS is given next. 

METHOD 33 - DETERMINATION OF P-TERT-BUTYL PERBENZOATE IN POLYSTYRENE. CATHODE-RAY POLAROGRAPHY. 

Determination of styrene and acrylonitrile monomers in styrene-acrylonitrile copolymers. Cathode-ray polarography... 

E. J. Maienthal, Analysis of botanical standard reference materials by cathode ray polarography, J. Assoc. Official Analytical Chemists 55, 1109-1113 (1972). 

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