Device and Method for Detecting an Analyte

Abstract

The invention relates to a device (1) for detecting an analyte in a gas mixture or a liquid, comprising: (a) a polymer sorption filter (2) configured to separate methanol from ethanol; and/or to separate hydrogen and/or methane from interferants; and (b) means configured to detect (4) at least one of methanol, ethanol, hydrogen and methane. Furthermore, described is a method for detecting an analyte using the device and the use of the device.

Claims

1.-19. (canceled)

20. A device for detecting an analyte in a gas mixture or a liquid, the device comprising: a polymer sorption filter configured to separate methanol from ethanol and/or to separate hydrogen and/or methane from interferants; and means configured to detect at least one of methanol, ethanol, hydrogen and methane.

21. The device of claim 20, wherein the gas mixture comprises breath, a headspace of a liquid and/or solid, or a liquid or solid that is at least partially transformed into a gaseous state.

22. The device of claim 20, wherein the device is configured to be held in a hand of a user.

23. The device of claim 20, wherein the device has a length of 20 cm or less and a width of 8 cm or less.

24. The device of claim 20, wherein the polymer sorption filter comprises nanoparticles, microparticles and/or porous materials.

25. The device of claim 20, wherein the polymer sorption filter comprises a polymer selected from the group consisting of polymers with phenyl groups, polyethers, acrylates, polyamines, polynitryles, poly(vinylpyridine), polyvinylpyrrolidone and polysiloxanes.

26. The device of claim 25, wherein the polymer with phenylgroups is a polyphenylether.

27. The device of claim 26, wherein the polyphenylether is poly(2,6-diphenylphenylene)oxide.

28. The device of claim 20, wherein the polymer sorption filter is configured as a packed bed of particles; as a coating; as a membrane; as a foam structure; or as an overlayer applied onto the means configured to detect at least one of methanol, ethanol, hydrogen and methane.

29. The device of claim 20, wherein the polymer sorption filter is present in an amount of 10 g or less.

30. The device of claim 20, wherein the polymer sorption filter has a specific surface area measured by BET nitrogen adsorption of 5 m.sup.2/g or more.

31. The device of claim 20, wherein a housing containing the polymer sorption filter has a cross-sectional area of 350 mm.sup.2 or less.

32. The device of claim 20, wherein the polymer sorption filter has a length of 20 cm or less.

33. The device of claim 20, wherein the polymer sorption filter is configured to be operated at a temperature of 200° C. or less.

34. The device of claim 20, wherein the means configured to detect at least one of methanol, ethanol, hydrogen and methane is a metal oxide gas sensor.

35. The device of claim 34, wherein the metal oxide gas sensor is selected from the group consisting of: an SnO.sub.2 sensor; a doped SnO.sub.2 sensor; a WO.sub.3 sensor; a doped WO.sub.3 sensor; a ZnO sensor; a doped ZnO sensor; an MoO.sub.3 sensor; a doped MoO.sub.3 sensor; an In.sub.2O.sub.3 sensor; a doped In2O3 sensor; a TiO.sub.2 sensor; and a doped TiO.sub.2 sensor.

36. A method for detecting an analyte in a gas mixture or a liquid using a device, the method comprising: separating methanol from ethanol and/or to separate hydrogen and/or methane from interferants by a polymer sorption filter of the device; detecting at least one of methanol, ethanol, hydrogen and methane by the device; and analyzing the gas or the liquid mixture by the device.

37. The method of claim 36, wherein the gas mixture comprises breathing air, a headspace of a liquid or solid, or a liquid or solid that is at least partially transformed into a gaseous state.

38. The method of claim 36, wherein the analyzing is carried out in 30 minutes or less.

39. The method of claim 36, wherein the polymer sorption filter is operated at a temperature of 200° C. or less.

40. A method of using a device configured to detect an analyte in a gas mixture or a liquid, the method comprising: separating methanol from ethanol and/or to separate hydrogen and/or methane from interferants by a polymer sorption filter of the device; and detecting at least one of methanol, ethanol, hydrogen and methane by the device, in breathing air, in a liquid, in a liquid or solid that is at least partially transformed into a gaseous state, or in a head space of a liquid.

Description

[0049] The present invention is further described by the following figures and examples. It is to be noted that the figures and the examples are only intended for illustrating the invention but not to restrict the invention thereto.

[0050] FIG. 1a, b shows the device according to the present invention.

[0051] FIG. 2 shows the response of a Pd-doped SnO.sub.2 sensor to various analytes.

[0052] FIG. 3a,b shows the response of a Pd-doped SnO.sub.2 sensor with a polymer sorption filter to various analytes.

[0053] FIG. 4a,b shows the relationship of the sensor response at different methanol concentrations.

[0054] FIG. 5 shows the response of a Pd-doped SnO.sub.2 sensor with a polymer sorption filter when sampling the headspace of rum with different amounts of methanol.

[0055] FIG. 6a,b shows the response a Pd-doped SnO.sub.2 sensor with a polymer sorption filter when sampling breath of a sober (FIG. 6a) and a drunken person (FIG. 6b).

[0056] In FIG. 1a, the device 1 according to the present invention is schematically shown for the example of an open-end configuration. The device contains a polymer sorption filter 2 which is connected by connection 3 with the means configured to detect 4. The polymer sorption filter 2 is connected with an inlet 7 for guiding the gas mixture into the polymer sorption filter 2. An example for the inlet 7 can be a mouth pipe for analyzing the breathing air. Furthermore, the means configured to detect 4 is connected by connection 5 with a pump 6 (optional) for pumping the gas mixture through the device if necessary. The detection of methanol poisoning in breathing air and spirits is carried out with the device 1 as follows. Breath or the headspace of a beverage is sampled by the pump 6 through the polymer sorption filter 2 to the means configured to detect 4. The polymer sorption filter 2 retains ethanol more strongly than methanol which is detected by the means for detecting 4 without interference within about 2 minutes.

[0057] In FIG. 1b, the device of FIG. 1 is shown in relation to the hand 8 of a human being. This figure shows that the device according to the present invention can be miniaturized in such a small and compact way so that it can be held in one hand of a human being.

[0058] FIG. 2 shows the responses of a Pd-doped SnO.sub.2 sensor without filter to 1 ppm of hydrogen, methanol, ethanol and acetone. The sensor is operated at 370° C. in a continuous flow of 25 ml/min synthetic air at 50% relative humidity. It can be taken from the results that each of hydrogen, methanol, ethanol and acetone can be detected by the used sensor, however, only in single gas mixtures, i.e. without interference. Thus, the sensor without filter is not able to distinguish, for instance, methanol from ethanol.

[0059] In FIG. 3a the response is shown of a Pd-doped SnO.sub.2 sensor with filter (100 mg porous poly(2,6-diphenylphenylene)oxide (Tenax TA) as porous polymer sorption filter, length is about 3 cm, cross section is 13 mm.sup.2, surface is 35 m.sup.2/g, operated at room temperature) to 10 s pulses of methanol (dash/dotted line), ethanol (dashed line) and acetone (dotted line) in a continuous flow of 50 ml/min synthetic air at 50% relative humidity. When exposing the sensor to a mixture of the same analytes, it detects each individually as they are completely separated by the filter as can be taken from FIG. 3b.

[0060] FIG. 4a shows the responses of a Pd-doped SnO.sub.2 sensor with filter (300 mg porous poly(2,6-diphenylphenylene)oxide (Tenax TA) as porous polymer sorption filter) when sampling methanol concentrations in the range 5-1000 ppm. Sensor response curves to low concentrations of methanol of 5 (solid line), 15 (dashed line) and 50 ppm (dotted line) is shown in FIG. 4b. Even these low but breath-relevant concentrations can be detected and are clearly distinguishable. Air was sampled continuously at 100 ml/min through the filter to the sensor by a pump. Samples were drawn for 10 s from Tedlar bags where the desired concentration of methanol was admixed with synthetic air at 50% relative humidity.

[0061] In FIG. 5 the response of a Pd-doped SnO.sub.2 sensor is represented with filter (150 mg porous poly(2,6-diphenylphenylene)oxide (Tenax TA) as porous polymer sorption filter) when sampling for 5 s in the headspace of a rum (40 vol. %) that was spiked with different amounts of methanol. Air was sampled continuously with 25 ml/min through the filter to the sensor with a pump. In all cases, the filter fully separates methanol from the high ethanol background and the sensor clearly distinguishes the samples containing toxic amount of methanol from the one without.

[0062] FIG. 6a and FIG. 6b show the response of a Pd-doped SnO.sub.2 sensor with filter (300 mg porous poly(2,6-diphenylphenylene)oxide (Tenax TA) as porous polymer sorption filter) when sampling breath of a (FIG. 6a) sober and (FIG. 6b) drunken person from a Tedlar bag for 5 sec. In both cases breath is sampled twice once analyzed as is (solid lines) and once after adding toxic concentrations of methanol (dotted lines). Air was sampled continuously with 50 ml/min through the filter to the sensor with a pump. The sensor completely separates methanol from hydrogen, methane, water and ethanol in the breath and clearly detects the toxic methanol concentration in the spiked samples.