Über die Anwendung der Kohlepaste-Elektrode zur inversvoltammetrischen Bestimmung kleiner Quecksilbermengen

The applicability of the carbon paste electrode to the determination of trace quantities of mercury has been investigated in a base electrolyte of 0.1 N KSCN + 0.025 N HCl containing 25 ng/ml copper. The detection limit of the mercury determination has a value near 2.5 ng/ml (1.25×10^?8 M), if pre-electrolysis is carried out 10 min at ?1.0 V and the current voltage curve is registered with a scan rate of 16.7 mV/sec between ?0.5 and +0.5 V. The peak height is directly proportional to the concentration in the range from 1.25×10^?8 to 1.25×10^?6 M. With appropriate preconditioning the carbon paste electrode can be used for several measurements without renewing the surface.