Microtrap assembly for greenhouse gas and air pollution monitoring
A microtrap assembly includes a carbon nanotube sorbent. The microtrap assembly may be employed as a preconcentrator operable to deliver a sample to an analytical device to measure the concentrations of greenhouse gases. A system includes a microtrap having a carbon nanotube sorbent for measuring the concentrations of greenhouse gases in a sample.
1. A system for detecting greenhouse gases comprising a microtrap assembly comprising at least one capillary tube comprising sorbent comprising carbon nanotubes and a temperature controlled chamber housing the microtrap assembly wherein the temperature controlled chamber is operable to lower a temperature of the microtrap assembly below ambient temperature.
2. The system according to claim 1 wherein the carbon nanotubes comprise multiwalled carbon nanotubes.
3. The system according to claim 1 wherein the sorbent consists of carbon nanotubes.
4. The system according to claim 1 wherein the sorbent consists of multiwalled carbon nanotubes.
5. The system according to claim 1 wherein the microtrap assembly comprises plural capillary tubes.
6. The system according to claim 1 consisting of a single capillary tube.
7. The system according to claim 1 wherein the capillary tube has an interior diameter of about 0.1 mm to about 5.0 mm.
8. The system according to claim 1 wherein the capillary tube has an interior diameter of 0.5 mm.
9. The system according to claim 1 wherein the microtrap is wrapped into a coil.
10. The system according to claim 1 wherein the microtrap has a length of about 1 cm to about 300 cm.
11. The system according to claim 1 wherein the microtrap has a length of about 1 cm to about 100 cm.
12. The system according to claim 1 wherein the microtrap has a length of about 15 cm.
13. The system according to claim 1 wherein the lengths of carbon nanotubes in the sorbent are from about 0.1 nm to about 400 micrometers.
14. The system according to claim 1 wherein the carbon nanotubes form a film thickness on the capillary tube of about 0.1 microns to about 2000 microns.
15. The system according to claim 1 wherein the carbon nanotubes form a film thickness on the capillary tube of about 0.1 microns to about 100 microns.
16. The system according to claim 1 further comprising a gas inlet and a detector or a gas chromatograph, wherein the microtrap assembly is operably connected to the gas inlet and the detector or gas chromatograph.
17. The system according to claim 16 further comprising a detector operably connected to a gas chromatograph.
18. The system according to claim 16 further comprising a power source operably connected to the microtrap assembly for providing resistive heating to the microtrap assembly and a timer operably connected to the power source to enable an electrical pulse to the microtrap assembly.
19. The system according to claim 16 further comprising a data acquisition device operably connected to a gas chromatograph.
20. The system according to claim 1 operably connected to a gas inlet and a detector, sensor or a gas chromatograph, wherein the system is operable to detect organic and inorganic air pollutants.
21. The system according to claim 20 , wherein the pollutant is a volatile organic compound.
22. The system according to claim 1 wherein the temperature controlled chamber is operable to cool the microtrap assembly below 20° C.
23. The system according to claim 1 wherein the temperature controlled chamber is operable to cool the microtrap assembly to at least −20° C.