Sample Retrieval Device for Environmental Aerosol Collection Used in Conjunction with a Field-Portable Time-of-Flight Mass Spectrometer
The remote collection of chemical and biological samples has become increasingly important in recent years. JHU/APL has developed a series of Field-Portable Time–of–Flight Mass Spectrometers to rapidly (<1 minute from receipt of sample) identify various pathogens and chemical agents. These devices must be taken to areas under investigation, where the samples are collected via aerosol impaction places in specific locations or manual swabbing of a target area. In both cases a person must go to the suspected location and gather the sample. Currently there are no methods for remote aerosol collection using retrievable air-frames that can be deployed in minutes and at a low cost.
Researchers at JHU/APL have developed this invention to provide an alternative method to current on-site monitoring. This development provides for lightweight aerosol collection devices in Unmanned Aerial Vehicles (UAVs, or radio controlled helicopters) to allow for high versatility, maneuverability, and rapid interrogation of otherwise inaccessible or hazardous environments. A radio controlled electric powered helicopter can be modified to include the aerosol collection system for use by first responders in both open field and closed building applications. The helicopter is both very maneuverable and clean (eliminating the possibility of fuel contamination) and can deliver a high volume of sample air to the collector, as well as hover in a single location to obtain time-sequenced samples. Modification of these commercially available, inexpensive and easy to deploy UAVs with a lightweight payload provides the perfect collection system.
The lightweight aerosol sampling device shown in Figure 1 is designed to mount under the central control module of a 4-propeler helicopter. It consists of dual intake ports and a small fan to create a negative pressure under the sampling surface. Power supply for the UAV can be utilized to supply the power to the sample collection device. Sample disks, based on the 3 inch mini-disk CD format shown in Figure 2 are indexed through the collectors by a stepping motor. This allows for numerous collections to be performed during a single flight. The disks are fabricated so that two tracks of collection spots (arranged in concentric circles) can be simultaneously positioned allowing for redundancy in the sample collection. Vent holes are drilled around each collection surface in order to maximize the throughput of the sampled aerosol. Collection surfaces are prepared using activated charcoal, adhesives, or other sample captivating substrates.
Following the collection cycle the flight vehicle is recovered, its sample disks are removed and loaded into a dual channel TOF mass analyzer designed specifically for this field portable application. The two channels on the disk are indexed through the two mass spectrometer channels allowing for rapid and redundant assessment of the environmental aerosol sample.
Patent Status: U.S. patent(s) 6854344 issued.CONTACT:
Dr. G. R. Jacobovitz
Phone: (443) 778-9899