| 摘要 |
<p>A mass spectrometer comprises an atmospheric pressure interface with a gas cone 6 and an electrospray ion source, which has a first capillary tube 2 for analyte liquid supply and a second capillary tube 3 for nebuliser gas supply which surrounds the first capillary tube 2. A desolvation gas supply tube and heater 4 surround the second capillary tube 3. The outlet of the first capillary tube 2 is x mm (millimetres) along an x-axis measured from the centre of the gas cone 6 inlet aperture, a distance y mm along a y-axis as measured from the centre of the gas cone 6 inlet opening and a distance z mm along a z-axis as measured from the centre of the gas cone 6 inlet aperture. The x-axis, the y-axis and the z-axis are mutually orthogonal. x is in the range 2.0-5.0 mm and the ratio z/x is in the range 1:1 to 5:1. The value range for x may reduce deleterious effects of gaseous ammonia or ionisation suppression effects due to buffer compounds. The device may be provided with fixed geometry to facilitate use by non-experts.</p> |
