Washington Tree Fruit Research Commission

Research Reports

Acquisition of a Agilent 5973N Bundled Gas Chromatograph with Chemical Ionization and Mass Selective Detector (2003)

WTFRC Project #AE-02-218
YEAR 0/0
Organization Project #
Title:Acquisition of a Agilent 5973N Bundled Gas Chromatograph with Chemical Ionization and Mass Selective Detector
PI:Vincent R. Hebert
Organization:Food and Environmental Quality Laboratory, WSU TriCities
 PDF version of report


Vincent P. Jones, Associate Entomologist and Jay F. Brunner, Entomologist, WSU-TFREC, Wenatchee


The acquisition of the Agilent 5973N gas chromatograph with chemical ionization and mass selective detector (GC/MS/CI) will:

1)       Provide benefits to tree fruit growers by making available an essential tool needed for evaluating the performance (i.e., pheromone release rates) of mating disruption systems.
2)       Provide analytical support for tree fruit IPM field research in the foreseeable future.
3)       Assist in the timely registration of current and emerging pesticide chemistries.

The Agilent GC/MS/CI system was purchased in July 2002.  The instrument was received and put on-line for analytical use in electron impact mode (EI) August 2002.  Final system checkouts for the chemical ionization unit were completed in December 2002.     

Significant findings

Conventional chemical analyses for volatile insect pheromones usually involve the use of a gas chromatograph (GC).  The GC separates individual chemical components in the complex mixture.  Each separate compound is then usually quantified using a flame ionization detector (FID). This detector basically burns and ionizes all the carbon in each separated chemical component.  This method of analysis requires a relatively large chemical concentration to acquire a good signal for quantitation.  Besides being insensitive, this form of ionization detection is nonspecific and not useful for assessing very low but bioactively significant pheromone concentrations that result in mating disruption in apple and pear orchard air.

Our preliminary method development findings using the GC/MS/CI show that both the electron impact (EI) and chemical ionization (CI) modes on the mass spectrometer have greatly enhanced sensitivity for codlemone quantitation compared to conventional GC/FID techniques.  We are currently in the process of quantifying low pico-to-fentogram concentrations per cubic meter of air.   In concert with trapping codlemone from air using high-volume air samplers, we fully anticipate to achieve sensitivities for chemically mapping the atmospheric release behavior of codlemone from two distinct mating disruption systems in the 2003 orchard growing season. 

Discussion of anticpated GC/MS uses in 2003

In 2003, we plan on sampling orchard air at regular intervals to determine chemical dissipation behavior in both sprayable and hand-applied dispenser products (2003 WTFRC new proposal submission).  The overall goal of this submission will be to provide environmentally relevant air concentration data that can be used in combination with dispenser release rate and pest monitoring data for assessing the performance and efficacy of mating disruption products.

This instrument will also see use in our on-going air monitoring program evaluating off-target movement of auxin agonist herbicides to wine grape vineyards.  2,4-D-type herbicides can be detected at extremely low air concentrations using the GC/MS in negative chemical ionization (NCI) mode.  This instrument will also provide needed specificity when sampling complex mixtures of organic substances from the ambient air.  Additionally, this instrument will be used to provide USDA IR-4 Magnitude of the Residue information in the fall of 2003 for supporting a lambda-cyhalothrin (Karate) pesticide registration in/on asparagus.

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