Method and device for the detection of not easily volatized substances

• Main Authors: KRAUSA MICHAEL, SCHORB KLAUS, BECKER FRANK, KREBS STEFAN
• Format: Patent
• Language: English
• Published: 11.10.2001
• Edition: 7
• Subjects: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; PHYSICS; TESTING

A method for the detection of not easily volatized substances in particular of nitrotoluene, trinitrotoluene, dinitrotoluene, or derivatives of nitrotoluene as well as chemical warfare substances such as Clark, Lewisite, Lost, Sarin, Soman, Tabun or the like in soil, liquid and gases, wherein an electrode configuration, comprising at least a working electrode and an opposing electrode, is brought into contact with a substance under examination via an electrolyte and a voltage is applied to the working electrode whose value is increased and decreased at least once with substantially equal beginning and end values within a predetermined time period, wherein the current strength is determined during this at least one measurement cycle in dependence on the applied voltage, is distinguished in that a plurality of measurement cycles are scanned, and differences of current values of sequential measurement cycles are determined and, in the event of the occurrence of a cathode current maximum, the associated voltage value is determined, held constant and the current strength extracted. A device is thereby utilized with which the electrolyte is in the form of a thin layer applied to the end of the sensor element coming in contact with the substance under investigation, the sensor element comprising at least a working and an opposing electrode.