Abstract: Provided is a method for introducing into a probe 22 an eluate eluted from a component separation unit 14 that temporally separates components contained in a liquid sample, for obtaining charged particles, and for delivering the charged particles to a charged particle analysis unit 30 provided at a subsequent stage through a charged particle introduction opening 23, comprising steps of: supplying a gasification promoting gas for promoting gasification of the eluate and applying a predetermined charged-particle obtaining voltage to the probe 22 while the eluate is being introduced into the probe 22; and hindering the eluate nebulized by the probe 22 from moving toward the ion introduction opening 2 only in a time period other than a time period in which a target-component containing eluate is introduced into the probe 22.

Abstract: In an LC/MS analysis of a sample containing various compounds, additive supply pumps 164A and 164B in a post-column adding unit 16 draw and supply different kinds of additives A and B from containers 163A and 163B, respectively. The additives are mixed into an eluate through T-joints 162 and 161. A preferable combination of the additives is the combination of DMSO which produces the effect of gathering charge states and 2-propanol which produces the effect of promoting atomization or vaporization of droplets. By mixing the two additives into the eluate while mixing them at an appropriate flow-rate ratio according to a previously determined flow-rate program, the ionization efficiency can be nearly optimized for each compound during the process of generating ions by spraying electrically charged droplets of the eluate from an ESI spray 21. Consequently, the detection sensitivity becomes higher than conventional levels.

Abstract: Provided is a method for introducing into a probe 22 an eluate eluted from a component separation unit 14 that temporally separates components contained in a liquid sample, for obtaining charged particles, and for delivering the charged particles to a charged particle analysis unit 30 provided at a subsequent stage through a charged particle introduction opening 23, comprising steps of: supplying a gasification promoting gas for promoting gasification of the eluate and applying a predetermined charged-particle obtaining voltage to the probe 22 while the eluate is being introduced into the probe 22; and hindering the eluate nebulized by the probe 22 from moving toward the ion introduction opening 2 only in a time period other than a time period in which a target-component containing eluate is introduced into the probe 22.

Abstract: In a liquid chromatograph mass spectrometer (LC/MS) for performing mass spectrometry of fractionated samples prepared with a multi-dimensional LC or similar LC with high separatory capability, fractionated sample useful information which shows the degree of usefulness of various substances with respect to retention time is prepared from prior information which includes, for example, elution characteristics in the LC depending on the kind of column or other factors or the degree of ease of ionization in the MS. During a measurement, the preparative separation of an eluate and the preparation of fractionated samples are not performed within a period of time which has been judged to be useless based on the fractionated sample useful information. By selecting fractionated samples at each dimension of the multi-dimensional LC, the number of fractionated samples to be eventually subjected to mass spectrometry can be significantly reduced.

Abstract: An imager 13 takes an image of a sample-placement surface of a sample plate 5. A plate identifier 103 decodes a barcode on the image to acquire a plate ID, recognizes the well arrangement, and retrieves a template having a cell arrangement corresponding to the well arrangement from a plate information storage section 101. A sample presence identifier 104 identifies, from the image, a well on which a sample is placed. A plate correspondence information input assistant 105 creates a template image in which the background color of the cells is changed depending on the presence of the sample, and displays it on a display unit 12. An analysis operator inputs information into each cell by a direct character-input operation or a drag-and-drop operation from a previously created sample list. The inputted information is associated with the corresponding well number and stored in a registration information storage section 107.

Abstract: In an LC/MS analysis of a sample containing various compounds, additive supply pumps 164A and 164B in a post-column adding unit 16 draw and supply different kinds of additives A and B from containers 163A and 163B, respectively. The additives are mixed into an eluate through T-joints 162 and 161. A preferable combination of the additives is the combination of DMSO which produces the effect of gathering charge states and 2-propanol which produces the effect of promoting atomization or vaporization of droplets. By mixing the two additives into the eluate while mixing them at an appropriate flow-rate ratio according to a previously determined flow-rate program, the ionization efficiency can be nearly optimized for each compound during the process of generating ions by spraying electrically charged droplets of the eluate from an ESI spray 21. Consequently, the detection sensitivity becomes higher than conventional levels.

Abstract: In a liquid chromatograph mass spectrometer (LC/MS) for performing mass spectrometry of fractionated samples prepared with a multi-dimensional LC or similar LC with high separatory capability, fractionated sample useful information which shows the degree of usefulness of various substances with respect to retention time is prepared from prior information which includes, for example, elution characteristics in the LC depending on the kind of column or other factors or the degree of ease of ionization in the MS. During a measurement, the preparative separation of an eluate and the preparation of fractionated samples are not performed within a period of time which has been judged to be useless based on the fractionated sample useful information. By selecting fractionated samples at each dimension of the multi-dimensional LC, the number of fractionated samples to be eventually subjected to mass spectrometry can be significantly reduced.

Abstract: The present invention provides a mass spectrometry method capable of detecting a smaller amount of peptide. A method for analyzing a peptide by matrix-assisted laser desorption/ionization mass spectrometry, comprising the steps of: dropping, onto a target plate, a peptide solution using, as a solvent, an aqueous solution containing 15 to 50 vol % of acetonitrile, and a matrix solution that uses, as a solvent, an aqueous solution containing 15 to 50 vol % of acetonitrile and that contains 0.05 to 1 mg/mL ?-cyano-4-hydroxycinnamic acid, respectively, to prepare a droplet of peptide-matrix mixed solution; removing the solvent from the droplet of peptide-matrix mixed solution to prepare a sample for mass spectrometry as a residue; and irradiating the sample for mass spectrometry with laser to detect the peptide.