Carl E. Moore

Studies in the tetraarylborates : The preparation and reagent properties of sodium tetrakis(p-chlorophenyl)borate

Abstract Sodium tetrakis(p-chlorophenyl)borate was synthesized. It formed precipitates with K+, Rb+, Cs+, quarternary ammonium and protonated basic nitrogen compounds. The potassium salt was more soluble than potassium tetraphenylborate but flocculated more readily and filtered more easily. The salts formed with nitrogen compounds offer possibilities as derivatives suitable for qualitative analysis.

Studies in the tetraarylborates

Abstract The stability of sodium tetraarylborates toward acid attack can be enhanced by placing electron-withdrawing substituents at the m - or p -positions of the phenyl rings, thus rendering them less susceptible to electrophilic attack. A series of tetraarylborates has been studied, and the following order of decreasing resistance toward acid attack has been established: m -fluorophenyl > p -trifluoromethylphenyl > m -trifluoromethylphenyl > p -fluorophenyl ≧ p -chlorophenyl ⋍ phenyl > p -methylphenyl > p -methoxyphenyl. Sodium tetrakis ( m -fluorophenyl) borate does not undergo acid decomposition at pH 2.0 and 50.0°, but it is partially decomposed under these conditions via other pathways.

Studies in the tetraarylborates: Part II. The preparation and reagent properties of sodium tetrakis(p-fluorophenyl)borate, a selective reagent for cesium

Abstract Sodium tetrakis(p-fluorophenyl)borate has been synthesized and found to be a very selective gravimetric reagent for the determination of cesium. It formed precipitates with cesium, silver, thallium(I) and rubidium but not with potassium and ammonium ions. The cesium tetrakis(p-fluorophenyl)borate separated as a white crystalline compound, which was easily filterable. It achieved constant weight rapidly at 110° and showed no signs of decomposition after 18 h of drying.

Studies in the tetraarylborates: The preparation and reagent properties of sodium tetrakis(p-trifluoromethylphenyl) borate and sodium tetrakis (m-fluorophenyl) borate

Abstract Sodium tetrakis(p-trifluoromethylphenyl) borate and sodium tetrakis(m-fluorophenyl) borate were synthesized by a new in situ method. Both salts formed precipitates with potassium, rubidium and cesium ions, quaternary ammonium and protonated basic nitrogen compounds. Potassium tetrakis(p-trifluoromethylphenyl) borate was more insoluble than potassium tetraphenylborate while cesium tetrakis (m-fluorophenyl) borate was less soluble than cesium tetrakis(p-fluorophenyl) borate. The salts formed with nitrogen-containing compounds offer possibilities for qualitative and quantitative analyses.

Instrumental analysis of trace elements in thumbnails of human subjects.

Human thumbnails were analyzed for trace elements by instrumental analysis using thermal neutron activation technique. The average concentration of metals studied in clinically symptom-free adult female and male subjects were: zinc, 184 vs. 153 ppm; chromium, 6.8 vs. 4.2; selenium, 0.9 vs. 0.6; gold, 2.6 vs. 0.4; mercury, 1.9 vs. 0.4; silver, 0.7 vs. 0.3; cobalt, 0.07 vs. 0.04. A summary of literature reported concentration of metals in human nail is also presented.

Determination of Trace Elements in Human Tissue. I. Cd, Fe, Zn, Mg, and Ca

Human tissues obtained at autopsy were analyzed for Cd, Fe, Zn, Mg, and Ca using atomic absorption spectrophotometry. The tissues analyzed included thoracic aorta collected from 46 subjects ranging in age from 1 to 91 years and lung, myocardium, and spleen collected from each of 26 additional subjects ranging in age from 5 months gestation to 78 years. The category of diseases included atherosclerotic heart disease (ASHD), malignancy (CA), and a miscellaneous group. The levels of the above elements are tabulated for the tissues indicated.

Studies in the tetraarylborates: Part IV. The, preparation and reagent properties of sodium tetrakis(m - trifluoromethylphenyl) borate

Sodium tetrakis(m-trifluoromethylphenyl)borate has been synthesized and shown to be a highly selective reagent for cesium ion even in the presence of other alkali metal ions. Equivalent amounts of rubidium or potassium do not interfere.

A Detailed Study of Lead Determinations in Air-Borne Particulates over Morton Grove, Illinois by Atomic Absorption Spectroscopy

Careful examination of an analytical method for the determination of lead concentrations in atmospheric particulates has confirmed that a low temperature ashing technique is preferable to the ashing of organic matter in a muffle furnace when preparing samples for metals analysis, and that use of the standard additions technique for the avoidance of interferences in the analyses by atomic absorption spectroscopy is justified. Analyses of some 600 samples collected from the air over Morton Grove, Illinois from 1964 through 1967 have revealed average suspended particulate concentrations but rather high lead concentrations for urban areas. Monthly mean lead contents, which were highest in the fall months, showed a gradual increase over the four years.

Studies in the tetraarylborates: Part 8. The synthesis and reagent properties of tetrathienylborates

Abstract The following cesium tetrathienylborates were synthesized and screened for gravimetric reagent properties: tetrakis(2-thienyl), tetrakis(3-thienyl), tetrakis(5-bromo-2-thienyl), tetrakis(5-chloro-2-thienyl),tetrakis(2,5-dimethyl-3-thienyl), tetrakis(5-ethyl-2-thienyl), tetrakis(5-methyl-2-thienyl), and tetrakis(5-t-butyl-2-thienyl). Of these, the tetrakis(5- alkyl-2-thienyl) borates were not sufficiently stable for complete characterization. The following are possible reagents for cesium and quaternary ammonium cations: sodium tetrakis(2-thienyl), tetrakis(3-thienyl), and tetrakis(2,5-dimethyl-3-thienyl)borates.

The gravimetric determination of cadmium with the sodium salt of 1-phenyl-tetrazoline-5-thione

Summary The use of the sodium salt of 1-phenyl-tetrazoline-5-thione provides a good method for the quantitative determination of cadmium, yielding a crystalline precipitate which is easily filtered and brought to constant weight. The precision of the determination is fair and the accuracy is generally withing 0.2 mg. The main limitation of the reagent is that it is not specific in its action and it might be necessary to effect a prior separation since cadmium is often found to be alloyed with lead and zinc.