Method and device for detecting fumigants in air samples

• US 7,459,483 B2
• Filed: 02/28/2002
• Issued: 12/02/2008
• Est. Priority Date: 02/28/2001
• Status: Expired due to Fees

• Current Assignee: Kanesho Soil Treatment SPRL/BVBA (Agro-Kanesho Co., Ltd.)
• Original Assignee: Kanesho Soil Treatment SPRL/BVBA (Agro-Kanesho Co., Ltd.)
• Inventors: Christen, Thomas, Ziegler, Hans, Probeck, Erich, Bargon, Joachim, Kober, Reiner, Horner, Gerhard, Stegmaier, Wolf, Voegtle, Fritz
• Primary Examiner(s): LEVY, NEIL S
• Application Number:
  US10/469,252
• Publication Number:
  US 20040079651A1
• Time in Patent Office: 2,469 Days
• Field of Search: None
• US Class Current: 514/514
• CPC Class Codes: G01N 2291/0212 Binary gases
• CPC Class Codes: G01N 29/036 by measuring frequency or resonance of acoustic waves
• CPC Class Codes: G01N 33/0004 Gaseous mixtures, e.g. polluted air gaseous biological material G01N33/497; exhaust gas of internal combustion engines G01M15/102
• CPC Class Codes: G01N 33/0047 for organic compounds
• CPC Class Codes: G01N 33/24 Earth materials G01N33/42 takes precedence

Abstract

The present invention relates to a method and a device for detecting fumigants in air samples. The device can be designed for example as a portable analyzer 10 equipped with a stab probe 11 for sampling soil air. There are provided detection means 16 which, upon contact with the air sample, generate electrical signals which depend on the concentration of the fumigants to be detected in the air sample. In accordance with the invention, the detection means 16 comprise at least one mass-sensitive sensor, for example an array of quartz microbalances, which have suitable selective surface layers.

Claims

1. A method for detecting methyl isothiocyanate in soil air samples, comprising:

drawing in a soil air sample;

bringing the drawn-in soil air sample into contact with at least one mass-sensitive sensor comprising at least one quartz microbalance;

detecting mass changes of the sensor in the form of electrical signals; and

evaluating the electrical signals to detect a change in mass of methyl isothiocyanate;

wherein;

the quartz micro-balance is coated with a surface layer that is selective for incorporation of methyl isothiocyanate; and

the quartz micro-balance comprises macrocycles and calibrated to detect methyl isothiocyanate.

2. A method as claimed in claim 1, wherein the at least one mass-sensitive sensor comprises a plurality of sensors coated with different selective layers.

3. A method as claimed in claim 1, wherein the methyl isothiocyanate to be detected is concentrated before making contact with the mass-sensitive sensor.

4. A method as claimed in claim 1, further comprising determining the moisture content of the air sample.

5. A method as claimed in claim 1, wherein moisture is removed from the air sample before it is brought into contact with the sensor.

6. A method of controlling phytopathogens, comprising:

treating soil with an effective amount of a methyl thioisocyanate generating fumigant; and

detecting residual amounts of released methyl isothiocyanate by the method of claim 1 before proceeding with new sowings or plantings of useful plants or crop plants in the soil.