| 摘要 |
A method for identifying and quantitatively analyzing an unknown organic compound in a gaseous medium. More specifically, the method provides a gas sensor array (120a, 120b, 120c, 120d) coupled to a diluting channeling gas inlet (105) with a honeycomb configuration. Each sensor (120a, 120b, 120c, 120d) in the array receives the test gas after successive dilutions. Detected gas are identified by correlating the responses of each sensor with its associated dilution. |
| 主权项 |
1. A method of detecting an unknown organic compound in a first gaseous medium, the method comprising:
providing a first sensor element comprising a first outer layer, a second outer layer, and a detection layer comprising a microporous material disposed between the first outer layer and the second outer layer, wherein at least one of the first outer layer or the second outer layer is permeable by the unknown organic compound, wherein the unknown organic compound has an unknown chemical identity, wherein the first sensor element has a first baseline response (R1o) with respect to a physical parameter in a second gaseous medium at a fixed temperature (To), and wherein the second gaseous medium is substantially equivalent to the first gaseous medium; providing a second sensor element, substantially identical to the first sensor element, wherein the second sensor element has a second baseline response (R2o) with respect to the physical parameter in the presence of the unknown organic compound in a third gaseous medium at To, wherein the third gaseous medium is substantially equivalent to the first gaseous medium; providing a reference library comprising a plurality of reference normalized response correlations, wherein each reference normalized response correlation corresponds to a different known reference organic compound having a respective different chemical identity, wherein each reference normalized response correlation is determined using a respective reference sensor element that is substantially identical to the first sensor element, wherein each reference normalized response correlation correlates a respective variable concentration (Crefvar) of a respective known reference organic compound with a respective quantity
(Rrefvar−Rrefo)/Rrefo wherein Rrefvar is a response of the respective reference sensor element with respect to the physical parameter at the respective variable concentration Crefvar of the respective known reference organic compound in a respective fourth gaseous medium at To, wherein the fourth gaseous medium is substantially equivalent to the first gaseous medium, and wherein Rrefo for each respective reference sensor element corresponds to a baseline response in the fourth gaseous medium at To;
obtaining an ambient sample containing the first gaseous medium and the unknown organic compound, wherein the unknown organic compound is present in an ambient concentration (Camb) in the ambient sample; preparing a first analytic sample from the ambient sample, wherein the first analytic sample includes a first concentration (C1) of the unknown organic compound in a fifth gaseous medium that is substantially equivalent to the first gaseous medium, wherein C1 is known relative to Camb; preparing a second analytic sample from the ambient sample, wherein the second analytic sample includes a second concentration (C2) of the unknown organic compound in a sixth gaseous medium that is substantially equivalent to the first gaseous medium, wherein C2 is known relative to Camb, wherein C1 and C2 are different, and wherein neither C1 nor C2 is zero; exposing the first sensor element to the first analytic sample, measuring a first response (R1) of the first sensor element with respect to the physical parameter at To, and obtaining a first normalized response
R1norm=(R1−R1o)/R1o; exposing the second sensor element to the second analytic sample, measuring a second response (R2) of the second sensor element with respect to a physical parameter at To, and obtaining a second normalized response
R2norm=(R2−R2o)/R2o; and comparing a data set comprising R1norm at C1 and R2norm at C2 to the plurality of reference normalized response correlations in the reference library; selecting a matched normalized response correlation that best matches the data set from among the plurality of reference normalized response correlations in the reference library; assigning the chemical identity of the known reference organic compound corresponding to the matched normalized response correlation to the unknown organic compound; and determining Camb, by determining a reference concentration Crefm associated with a normalized response value equal to R1norm of the matched normalized response correlation, and then multiplying Crefm by a known factor equal to Camb/C1. |
