Ultra Micro Procedure for Udmh in Blood

Electrochemistry of boron compounds

“…At the other electrodes no steady potentials could be recorded, and the BH4" was not oxidized readily until the potential approached that of oxygen discharge (~0.8 V). Further support for the mechanism proposed (eq [19][20][21][22][23][24][25] was found in the similar polarization behavior of an aqueous solution of tetrahydroborate ion and aqueous diborane, both sources of borane radicals.…”

“…From a general consideration of the overpotential and stoichiometric results, the following reaction scheme was proposed for the anodic behavior of the tetrahydroborate ion at a platinum surface. initial step BH4-+ Pt -2e" -Pt-BH3 + H+ (19) Pt-BH3 + OH" -Pt-BH3OH_ (20) rate-determining step Pt-BH3OH--2e" -Pt-BH2OH + H+ (21) Pt-BH2OH + H20 -Pt + BH2(OH)2-+ H+ (22) slow hydrolysis Pt-BH3OH-+ H20 -Pt + BH2(OH)2-+ H2 (23) completion step BH2(OH)2-+ H20 -BH(OH)3-+ H2 (24) BH(OH)3--H2B03-+ H2 (25) The competition between the slow electrochemical oxidation and the corresponding hydrolysis accounts for the different behavior at various electrode surfaces. For smooth platinum, platinized platinum, and gray platinum, reproducible static potentials of -0.827, -0.828, and -0.927 V, respectively (0.01 M KBH4, 0.1 M KOH), were measured, potentials substantially more negative than the reversible hydrogen potentials in the same solutions (e.g., -0.751 V in 0.1 M KOH).…”