The present disclosure provides a method for detecting short-chain fatty acids in biological samples, including a derivatizing step, a loading step and a detecting step. The derivatizing step includes treating the short-chain fatty acids in the biological sample with 2-nitrophenylhydrazine for derivatizing the short-chain fatty acids into a sample to be detected. The loading step includes loading the sample onto a paper carrier. The detecting step includes analyzing the sample loaded onto the paper carrier by direct analysis in real time mass spectrometry for obtaining a detection result. The method provided by the present disclosure may complete the analysis of the biological sample within a short period of time and achieve a quantitative result comparable to that obtained by conventional chromatographic approaches.

Techniques and systems for multi-modal ionization for mass spectrometry are provided. In some embodiments, a method may comprise: receiving an analyte; ionizing some molecules of the analyte using a first ionization method to produce first ions; ionizing other molecules of the analyte using a second ionization method to produce second ions; and providing the first and second ions to a mass analyzer.

A method of mass spectrometry comprising the steps of: providing a library of background ion data including m/z data for multiple background ions in respect of different chromatographic conditions including a change of solvent composition from aqueous (1) to organic (3), chromatographically separating a sample containing analyte components, wherein the chromatographic separation is performed under a chromatographic condition in respect of which background ion data is provided in the library, analysing the sample to obtain sample data comprising m/z values for the sample components as a function of retention time (RT), and calculating one or more error values including ppm error as a function of retention time based on a comparison between background ions identified in the sample data and the library of background ion data. Outliers (4), corrupted measurements and inconsistent measurements at specific retention times are rejected.

A method of separating a sample of ions according to their ion mobilities is provided. The method comprises receiving the sample of ions into a drift tube; applying a first electric field component within the drift tube so as to cause the sample of ions to move along a path within the drift tube, whereby the sample of ions separates along the path; and applying a second electric field component within the drift tube. The first and second electric field components have a combined electric field strength to modify the ion mobility of at least a portion of the sample of ions and to increase the separation of at least a portion of the sample of ions along the path The second electric field component substantially does not cause a net change in the velocity of the sample of ions perpendicular to the path. An apparatus for separating a sample of ions according to their ion mobilities is also provided.

A protection device for an Optical Emission Spectrometer (OES) and a method of protecting a detector to which purge gas is supplied, in an OES, are disclosed. The protection device comprises a timer, which measures a parameter, such as a humidity value, indicative of a shut down time period following cessation of application of purge gas to the detector. The protection device comprises a processor, which determines a start-up time period, based on the parameter, during which purge gas is supplied to the detector prior to cooling of the detector. The processor may selectively trigger commencing or maintaining application of purge gas to the detector or cooling of the detector in dependence on the parameter.

A mass spectrometer system comprises: (a) an ion source; (b) a mass filter or a time-of-flight (TOF) ion separator configured to receive a stream of first-generation ions from the ion source; (c) an ion storage device having an ion inlet configured to receive a stream of filtered ions comprising a plurality of ion species from the mass filter or TOF separator and to accumulate the plurality of ion species therein; (d) an ion mobility cell having an ion inlet configured to receive an accumulated batch of ion species from the ion storage device and an ion outlet configured to release, one at a time, the individual ion species therefrom; and (e) a mass analyzer configured to receive and mass analyze each first-generation ion species or each fragment ion species generated by fragmentation or other reaction of the various first-generation ion species.

Examples are directed toward systems and methods relating to collecting and analyzing samples. For example, a system includes a cold trap that directly collects a sample. The cold trap operates to serve as a collection filter while the system draws in a flow across the cold trap. A thermal heater, coupled to the cold trap, flash heats the cold trap to produce a released sample from the cold trap at a release concentration. An analyzer entrains the released sample at the release concentration into a sampling flow of the analyzer for analysis.

Methods for an instrument including a light source of are provided. A method for an instrument including a light source includes providing light from the light source to a target location in a process chamber. The method includes receiving the light at a sensor. The method includes determining, using data from the sensor, a first position of the light at the target location. Moreover, the method includes determining whether to adjust the light to a second position at the target location. Related instruments are also provided.

The present invention relates to compounds which are suitable to be used in mass spectrometry as well as methods of mass spectrometric determination of analyte molecules using said compounds.

A method for correcting mass spectral data obtained for a sample is described, where the mass spectral data is a time-of-flight mass spectral data. The method includes receiving mass spectral data obtained from a sample, the mass spectral data being indicative of an ion abundance. The method further includes applying a correction function to the mass spectral data based on the ion abundance indicated by the mass spectral data and on one or more trapping parameters associated with the mass spectral data. The correction function defines correction values for the mass spectral data for a range of ion abundances and for a range of trapping parameters.