Abstract: A mass spectrometry apparatus includes means to irradiate a specimen with a beam of radiation to desorb ions for mass analysis. The apparatus comprises means for deflecting and scanning the beam and attenuator means arranged to vary the attenuation of the beam such that the attenuation is a function of the beam position in the scan.

Abstract: A sample for analysis by Laser Desorption Mass Spectrometry is prepared by dissolving the sample material in a solvent and applying the solution to a matrix material. The matrix material is applied to a target for a mass spectrometer prior to the application of the sample solution thereto.

Abstract: A sample for analysis by Laser Desorption Mass Spectrometry is prepared by dissolving the sample material in a solvent and applying the solution to a matrix material applied to a target for a mass spectrometer. The matrix material is selected from the group consisting of (i) cis-Cinnamic Acid with the aromatic ring substituted by one or more groups which possess an electron pair on the atom adjacent to the ring; (ii) trans-Cinnamic Acid with the aromatic ring substituted by one or more groups which possess an electron pair on the atom adjacent to the ring; (iii) Benzoic Acid, with one or more substituent groups as described in (i); and (iv) Coumarin, with one or more substituent groups as described in (i).

Abstract: A sample for analysis by Laser Desorption Mass Spectrometry is prepared by applying a substrate material to a target for the mass spectrometer, dissolving the sample material in a solvent and applying the solution to a substrate material on the target to be absorbed thereby. A matrix material is also dissolved in a solvent and this matrix material in solution is applied to the substrate material on the target. The solvent used to dissolve the matrix material is chosen such as to release the sample material from the substrate so that, after evaporation of the matrix material, there is provided on the substrate material an intimately mixed deposit of sample material and matrix material.

Abstract: A probe for supporting a sample in an ion source of a mass spectrometer comprises a target formed by a copper probe tip for a liquid sample in which the sample passes through a fine bore 18a of the tip on to the end surface of the tip where it is held as a droplet by surface tension. In order to replenish the droplet surface, capillary tubing leads from a syringe to the inlet end of the bore in the probe tip.

Abstract: A probe and method for using the same for supporting a sample in an ion source of a mass spectrometer comprises a target formed by a receptacle for a liquid sample in which the sample passes by diffusion to the high vacuum side of a semipermeable membrane and/or in which the sample is held as a droplet by surface tension. In order to replenish the droplet surface, the supply can be arranged to overflow the receptacle.

Abstract: In a mass spectrometer, suitable for use in the determination of isotope ratios, having as a mass selector a sector magnet and detector means for detecting and measuring the intensity of ion beams at two or more positions in the focal plane of said sector magnet, the improvement comprises providing the exit (and optionally also the entrance) pole face of said sector magnet with a curvature such that the focal plane of said sector magnet lies substantially at right angles to the ion optical axis as it passes through said focal plane. With this arrangement, motion of detector means between positions in said focal plane by means of mechanical linkages controlled from outside the vacuum system of the mass spectrometer is facilitated.

Abstract: The invention relates to a detergent composition in powder or bar form containing a surfactant, an alkali metal carbonate and a low level (1 to 12%) of pyrophosphate, other phosphates being maintained at a level below 5%. A peroxygen bleach and other conventional additives are optionally present. The compositions are suitable for washing fabrics in developing countries and are suitable for low cost products elsewhere.

Abstract: The invention relates to a detergent composition in powder or bar form containing a surfactant, an alkali metal carbonate and a low level (1 to 5%) of orthophosphate, other phosphates being maintained at a level below 5%. A peroxygen bleach and other conventional additives are optionally present. The compositions are suitable for washing fabrics in developing countries and are suitable as low cost products elsewhere.