Patent ID: 6166379
Filing Date: 2000-12-26
Classification: G01N,H01J

Abstract:
A method of delivering a sample comprised of liquid for analysis by spectrometry, comprising:providing a direct injection nebulizer that includes an elongate tubular shell having a gas input port and a gas output port, and that includes a capillary tube within the tubular shell, the capillary tube having a sample input port and a sample output port, in which the shell has a terminus at the gas output port, and the capillary tube has a terminus at the sample output port, the capillary tube terminus being substantially at or proximal to the shell terminus;inserting the direct injection nebulizer into a torch box;converting the liquid into an aerosol consisting substantially of droplets having a Sauter mean diameter (as determined with respect to normalized volume percent) of less than about 15 micrometers at a point along a centerline of the aerosol at a distance of 15 mm from the terminus of the shell, said converting comprising nebulizing the liquid with the gas by:(a) outputting gas from the gas output port of the elongate tubular shell without outputting gas from an auxiliary nebulizer gas passageway; and(b) passing the liquid from the sample input port to the sample output port of the capillary tube at a flow rate substantially less than 100 .mu.L/min by (i) drawing the liquid out of the capillary tube without a pump using the Venturi effect caused by said outputting gas from the gas output port or (ii) using a low pressure pump to supplement the Venturi effect such that pressure applied to the liquid is not substantially greater than that provided by a peristaltic pump; anddirectly injecting the aerosol towards an interaction region of the torch box.