Patent ID: 6521119
Filing Date: 2003-02-18
Classification: G01N

Abstract:
A method for the detection of a not easily volatized substance such as nitrotoluene, trinitrotoluene, dinitrotoluene and derivatives of nitrotoluenes as well as chemical warfare materials such as Clark, Lewisite, Lost, Sarin, Soman, Tabun and the like in soil, liquid and gas, the method comprising the steps of:a) applying a viscous electrolyte layer to an electrode configuration, said electrode configuration comprising at least a working electrode and an opposing electrode, said viscous electrolyte applied to completely cover said working electrode and said opposing electrode; b) bringing the substance into contact with said electrode configuration such that the substance only contacts said working electrode and said opposing electrode via said viscous electrolyte layer; c) applying a voltage to said working electrode; d) increasing said voltage and decreasing said voltage in a first measuring cycle between substantially equal beginning and ending voltage values and within a predetermined period; e) determining cathodic current values occurring during step d) in dependence on said increasing and decreasing voltage; f) extracting at least one cathodic current maximum at at least one associated first voltage; g) keeping said first voltage of step f) constant and successively determining associated cathodic current strengths as a function of time at said constant first voltage until said cathodic currents strengths remain substantially unchanged; and h) determining a substance concentration from said substantially unchanged cathodic current strengths.