Open Air Desorption Ionization of Apple Juice

DART-MS analysis of Apple Juice is facilitated by using Experiment modules that position samples in the desorption ionization region of the DART source

Samples can either be quickly inserted into the desorption ionization region using an automated X-Y sample positioning stage

Individual aliquots of juice or extract are positioned on separately addressable glass inserts to facilitate more reproducible analysis

The DART SVP control software controls the type of movement, gas temperature, ionization mode, and exposure time for the experiment

48-Well Plate with Inverted Glass Inserts

• Sampling using the 3+D scanner module.
• Microtiter plate populated with glass inserts in every other row
• Up to 10 ul of a liquid samples can be pipetted onto the top surface of the glass inserts
• One glass insert per sample isolates each sample from the next so that each analysis starts with the same temperature surface
• The Angle DART SVP option is used for more efficient desorption
• VAPUR® is used to permit sampling from the furthest position on the plate

APPLE JUICE, DART-MS

• 10 ul of Apple Juice applied to top of insert.
• Carbohydrate related ions present and
dominate the positive ion mass spectrum
• Few ions detected in the negative ion mass spectrum
• Analysis complete in 10 seconds per sample using automated positioning with the 3+D Scanner

3+D Scanner, Analyzing a Pesticide Mixture

• Pesticide Mix
• Contained 140 pesticides
• Most of the pesticide standards were obtained from the U.S. EPA Pesticide Repository (Ft. Meade, MD), whereas others were obtained through Fluka/Sigma Aldrich (St. Louis, MO), Wako Chemicals USA (Richmond, VA),Honeywell Riedel-de Haën (Seelze, Germany), and EQ Laboratories, (Atlanta, GA).

Pesticide Standards in Apple Juice

Positive ion DART-MS mass chromatograms for three of the major protonated pesticides detected in 20 replicate analysis and undetected in 4 control samples

Negative ion DART-MS mass chromatograms for three of the major pesticides detected in 20 replicate analysis and undetected in 4 control samples