Electrophoretic separation of catecholamine metabolites and the quantification of norepinephrine-7H3 metabolites in man

Determination of (catecholato)borate complexes using difference spectrophotometry

“…For example, we have recently reported a procedure for dissolving Du Font's Nafion polymers (5); because this procedure uses elevated temperatures and pressures, it was important to assess whether any damage occurred to the polyion during the dissolution procedure (5). One way of assessing this is through an EW determination (5) The luminescence probe technique has proved to be useful for studying the chemical and morphological characteristics of polyelectroiytes (7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18). We recently reported (16) a luminescence probe study of the polyelectroiytes obtained by dissolving (5) the Nafion polymers.…”

“…Ligand binding studies have determined that catechols form primarily 1:1 complexes with borate (2, 3); the complexes have stability constants ranging from 104 to 106 and exhibit maximal association at pH 8 to 9 (2)(3)(4)(5)(6). Today the chelation of boronic acids is commonly exploited to separate or purify catecholic compounds by affinity chromatography (7)(8)(9) and electrophoresis (10)(11)(12).…”

The Metabolism of Norepinephrine in Depressions: Differences and Effects of Therapies

“…Urine specimens kept in the deep freeze for three months showed no change, although a significant alteration in the composition of the tritiated metabolites did occur some time after this period. The nature and relative percentages of the metabolic products were determined with a high degree of accuracy by a new method developed in our laboratory which combines both paper electrophoresis and chromatography (9). The initial step in this procedure consists of the paper electrophoresis in borate buffer of a concentrated aliquot of urine.…”