Abstract: A detector comprising an analytical apparatus for detecting a substance of interest, and a detector inlet. The detector inlet comprises a flow passage for carrying a flow of fluid, the flow passage comprising a sampling volume, and a sampling inlet adapted to collect samples of the fluid from the sampling volume as the fluid flows past the sampling inlet, and to provide the samples to the analytical apparatus, wherein the flow of fluid carries particulates. The detector inlet also comprises a flow director arranged to vary a spatial distribution of the particulates carried by the fluid to increase a relative proportion of the particulates carried past the sampling inlet along the flow passage without entering the sampling volume.

Abstract: A method of operating an air purification system (24?) of an ion mobility spectrometer, the method comprising: operating the ion mobility spectrometer in a first sampling mode comprising circulating a flow of air around a closed air circulation system comprising a drift chamber (12) of the ion mobility spectrometer and a first sieve (70) of the air purification system; and operating the ion mobility spectrometer in a first regeneration mode comprising heating the first sieve and circulating a first flow of air through a second sieve (72) of the air purification system and through the drift chamber (12) while passing a second flow of air through the first sieve (70) to an outtake (76).

Abstract: A method of operating an ion mobility spectrometer comprises the following steps: drawing a sample of gaseous fluid into a reaction region of the ion mobility spectrometer; providing a first pulse of a pulsed ionisation source to ionise the sample of gaseous fluid, thereby to obtain first sample ions; after a first gate delay following the first trigger opening an ion shutter to permit a portion of the first sample ions to leave the reaction region; providing a second pulse of the pulsed ionisation source to further ionise the sample of gaseous fluid, thereby to obtain second sample ions; after a second gate delay following the first trigger opening the ion shutter to permit a portion of the second sample ions to leave the reaction region, wherein the second gate delay is different from the first gate delay.

Abstract: A detector inlet for providing a sample to an analytical apparatus for detecting an aerosol, the detector inlet comprising; an intake for inhaling a flow of gaseous fluid to be sampled by the analytical apparatus; a mixing region; a first conduit for carrying a first part of the flow of gaseous fluid from the intake to the mixing region; a second conduit for carrying a second part of the flow of gaseous fluid from the intake to the mixing region; and a heater configured to heat the first part more than the second part, and wherein the detector inlet is configured to combine the first part with the second part in the mixing region.

Abstract: A portable ion mobility spectrometry apparatus (1) for detecting an aerosol and a method for using the apparatus. The apparatus comprises an ion mobility spectrometer (3); a portable power source (5) carried by the apparatus for providing power to the apparatus (1); an inlet (7) for collecting a flow of air to be tested by the spectrometer (3); a heater (4) configured to heat the air to be tested to vapourise an aerosol carried by the air and a controller (2) configured to control the spectrometer (3) to obtain samples from the heated air, wherein the controller is configured to increase a heat output from the heater (4) for a selected time period before obtaining samples from the heated air.

Abstract: A detector comprising an analytical apparatus for detecting a substance of interest, and a detector inlet. The detector inlet comprises a flow passage for carrying a flow of fluid, the flow passage comprising a sampling volume, and a sampling inlet adapted to collect samples of the fluid from the sampling volume as the fluid flows past the sampling inlet, and to provide the samples to the analytical apparatus, wherein the flow of fluid carries particulates. The detector inlet also comprises a flow director arranged to vary a spatial distribution of the particulates carried by the fluid to increase a relative proportion of the particulates carried past the sampling inlet along the flow passage without entering the sampling volume.

Abstract: An ion filter for a mass spectrometer, the apparatus comprising an ion modifier; an ion selector configured to select a subset of a sample of ions based on their mobility in a gas; and a controller configured to operate the ion modifier in a first mode to modify the ions selected by the ion selector to provide daughter ions, and configured to operate the ion modifier in a second mode to output the ions selected by the ion selector; wherein the ion filter is adapted for providing output ions from the ion modifier to an intake of a mass spectrometer.

Abstract: A detector comprising an analytical apparatus for detecting a substance of interest, and a detector inlet. The detector inlet comprises a flow passage for carrying a flow of fluid, the flow passage comprising a sampling volume, and a sampling inlet adapted to collect samples of the fluid from the sampling volume as the fluid flows past the sampling inlet, and to provide the samples to the analytical apparatus, wherein the how of fluid carries particulates. The detector inlet also comprises a flow director arranged to vary a spatial distribution of the particulates carried by the fluid to increase a relative proportion of the particulates carried past the sampling inlet along the flow passage without entering the sampling volume.

Abstract: An ion mobility spectrometry method comprising (i) applying a voltage difference between a first electrode of an ion gate and a second electrode of the ion gate to prevent ions from leaving a reaction region of an ion mobility spectrometer; (ii) opening the ion gate to allow the ions to travel from the reaction region into a modification region between the first electrode and the second electrode; (iii) applying a radio frequency, RF, voltage between the first electrode and the second electrode to fragment the ions in the modification region to provide daughter ions;(iv) allowing the daughter ions to travel from the modification region into a drift region of the ion mobility spectrometer towards a collector; (v) closing the ion gate; and (vi) determining the time of flight of the daughter ions from the ion gate to the collector.

Abstract: A portable ion mobility spectrometry apparatus (1) for detecting an aerosol and a method for using the apparatus. The apparatus comprises an ion mobility spectrometer (3); a portable power source (5) carried by the apparatus for providing power to the apparatus (1); an inlet (7) for collecting a flow of air to be tested by the spectrometer (3); a heater (4) configured to heat the air to be tested to vapourise an aerosol carried by the air and a controller (2) configured to control the spectrometer (3) to obtain samples from the heated air, wherein the controller is configured to increase a heat output from the heater (4) for a selected time period before obtaining samples from the heated air.

Abstract: A detector inlet for providing a sample to an analytical apparatus for detecting a substance of interest, the detector inlet comprising a plenum for allowing passage of a flow of a gaseous fluid, the plenum comprising a sampling volume a sampling inlet arranged in the plenum and arranged to collect samples of the gaseous fluid from the sampling volume and to provide the samples to the analytical apparatus, wherein the flow carries particulates and a flow director arranged to create circulatory flow of the gaseous fluid around the plenum encircling the sampling inlet thereby to vary a spatial distribution of the particulates carried by the fluid to increase a relative proportion of the particulates carried past the sampling inlet without entering the sampling volume.

Abstract: A portable ion mobility spectrometry apparatus (1) for detecting an aerosol and a method for using the apparatus. The apparatus comprises an ion mobility spectrometer (3); a portable power source (5) carried by the apparatus for providing power to the apparatus (1); an inlet (7) for collecting a flow of air to be tested by the spectrometer (3); a heater (4) configured to heat the air to be tested to vapourise an aerosol carried by the air and a controller (2) configured to control the spectrometer (3) to obtain samples from the heated air, wherein the controller is configured to increase a heat output from the heater (4) for a selected time period before obtaining samples from the heated air.

Abstract: An ion mobility spectrometer comprising an ioniser for ionising a sample; a detector separated from the ioniser by a drift chamber along which ions can travel from the ioniser toward the detector; a gate for controlling the passage of ions from the ioniser to the drift chamber; an ion modifier arranged between the ioniser and the detector and comprising a first electrode and a second electrode; and a voltage provider configured to provide a time varying voltage between the first electrode and the second electrode wherein the time varying voltage has a frequency of at least 2.5 MHz.

Abstract: A detector comprising an analytical apparatus for detecting a substance of interest, and a detector inlet. The detector inlet comprises a flow passage for carrying a flow of fluid, the flow passage comprising a sampling volume, and a sampling inlet adapted to collect samples of the fluid from the sampling volume as the fluid flows past the sampling inlet, and to provide the samples to the analytical apparatus, wherein the how of fluid carries particulates. The detector inlet also comprises a flow director arranged to vary a spatial distribution of the particulates carried by the fluid to increase a relative proportion of the particulates carried past the sampling inlet along the flow passage without entering the sampling volume.

Abstract: An ion filter for a mass spectrometer, the apparatus compr sing an ion inodifier; an ion selector configured to select a subset of a sample of ions based on their mobility in a gas; and a controller configured to operate the ion modifier in a first mode to modify the ions selected by the ion selector to provide daughter ions, and configured to operate the ion modifier in a second mode to Coutput the ions selected by the ion selector;wherein the ion filter is adapted for providing output ions from the ion modifier to an in-take of a mass spectrometer.

Abstract: A detector comprising an analytical apparatus for detecting a substance of interest, and a detector inlet. The detector inlet comprises a flow passage for carrying a flow of fluid, the flow passage comprising a sampling volume, and a sampling inlet adapted to collect samples of the fluid from the sampling volume as the fluid flows past the sampling inlet, and to provide the samples to the analytical apparatus, wherein the flow of fluid carries particulates. The detector inlet also comprises a flow director arranged to vary a spatial distribution of the particulates carried by the fluid to increase a relative proportion of the particulates carried past the sampling inlet along the flow passage without entering the sampling volume.

Abstract: An ion mobility spectrometer comprising an ioniser for ionising a sample; a detector separated from the ioniser by a drift chamber along which ions can travel from the ioniser toward the detector; a gate for controlling the passage of ions from the ioniser to the drift chamber; an ion modifier arranged between the ioniser and the detector and comprising a first electrode and a second electrode; and a voltage provider configured to provide a time varying voltage between the first electrode and the second electrode wherein the time varying voltage has a frequency of at least 2.5 MHz.

Abstract: An ion filter for a mass spectrometer, the apparatus comprising an ion modifier; an ion selector configured to select a subset of a sample of ions based on their mobility in a gas; and a controller configured to operate the ion modifier in a first mode to modify the ions selected by the ion selector to provide daughter ions, and configured to operate the ion modifier in a second mode to output the ions selected by the ion selector; wherein the ion filter is adapted for providing output ions from the ion modifier to an intake of a mass spectrometer.

Abstract: Ion modification An ion mobility spectrometer (100) comprising a sample inlet (108) comprising an aperture arranged to allow a sample of gaseous fluid to flow from an ambient pressure region to a low pressure region of the ion mobility spectrometer to be ionised; a controller (200) arranged to control gas pressure in the low pressure region to be lower than ambient pressure; and an ion modifier (126, 127, 202) configured to modify ions in the low pressure region, wherein the ions are obtained from the sample of gas.

Abstract: An ion mobility spectrometer comprising an ionizer for ionizing a sample; a detector separated from the ionizer by a drift chamber along which ions can travel from the ionizer toward the detector; a gate for controlling the passage of ions from the ionizer to the drift chamber; an ion modifier arranged between the ionizer and the detector and comprising a first electrode and a second electrode; and a voltage provider configured to provide a time varying voltage between the first electrode and the second electrode wherein the time varying voltage has a frequency of at least 2.5 MHz.