The voltammetric determination of 4-nitrobiphenyl

Optimum conditions were found for the determination of 4-nitrobiphenyl by fast scan differential pulse voltammetry at a hanging mercury drop electrode in the concentration range 1 . 10-5 to 2 . 10-7 mol l-1. A further increase in sensitivity was attained by adsorptive accumulation of this substance on the surface of the working electrode, permitting determination in the concentration range (2 – 10) . 10-8 mol l-1 with one minute accumulation of the substance in unstirred solution or (2 – 10) . 10-9 mol l-1 with three-minute accumulation in stirred solution. Linear scan voltammetry can be used to determine 4-nitrobiphenyl in the concentration range (2 – 10) . 10-9 mol l-1 with five-minute accumulation in stirred solution, with the advantage of a smoother baseline and smaller interference from substances that yield only tensametric peaks.

An ultramicro oxygen electrode

The advantages of a 1-μ-diameter platinum cathode in the Clark-type oxygen electrode are shown to be freedom from effects due to flow, stirring, or mechanical pressure. When used with a 5-mil polyethylene membrane the 1-μ electrode shows only a 2% difference between a vigorously stirred solution and the unstirred solution. A mechanical pressure of 200 psi on the 1-μ covered electrode caused only a 20% reduction in current. The use of a 1-μ covered electrode as an implant is suggested. electrode implant; Clark-type oxygen electrode modification; polarographic electrode; oxygen measurement; platinum electrode Submitted on March 4, 1963