摘要:
A torch for Inductively Coupled Plasma Spectrometry (ICPS) is formed from quartz and has inner and outer tubes defining an annular channel. The end of the inner tube is within an end portion of the outer tube, to define a chamber for a plasma ball. An inlet for a main gas flow opens tangentially into the annular channel. The annular channel is configured so as to maximize the swirl component of this flow. To this end, a connection to the inlet is provided with an annular toroidal shape, having a cross section to or larger than the inlet. Further, the inlet is mounted relatively close to the end of the inner tube, so as to minimise decay of the swirl component as the gas flows along the annular channel, the length of the annular channel being sufficient to ensure that the flow leaving the annular channel is uniform and has a uniform swirl component. This arrangement enables a significantly reduced consumption of gas to generate a plasma ball, and can give improved performance, in terms of a higher detection rate in a spectrometer.
摘要:
A torch for Inductively Coupled Plasma Spectrometry (ICPS) is formed from quartz and has inner and outer tubes defining an annular channel. The end of the inner tube is within an end portion of the outer tube, to define a chamber for a plasma ball. An inlet for a main gas flow opens tangentially into the annular channel. The annular channel is configured so as to maximize the swirl component of this flow. To this end, a connection to the inlet is provided with an annular toroidal shape, having a cross section to or larger than the inlet. Further, the inlet is mounted relatively close to the end of the inner tube, so as to minimise decay of the swirl component as the gas flows along the annular channel, the length of the annular channel being sufficient to ensure that the flow leaving the annular channel is uniform and has a uniform swirl component. This arrangement enables a significantly reduced consumption of gas to generate a plasma ball, and can give improved performance, in terms of a higher detection rate in a spectrometer.
摘要:
A spray chamber for producing a sample for an analyzer which may contain a plasma torch. In the chamber, a heated sheath gas is fed into the periphery of the spray surrounding the spray, adjacent the origin of the spray, thus reducing the size of droplets which are recirculated, thereby reducing agglomeration of the droplets and promoting rapid drying of the spray. Preferably all of the spray solvent is evaporated in a very short chamber, thus further reducing the amount of spray recirculated, and all of the combined flow of dried particulates from the spray, nebulizing gas and sheath gas is directed into the torch. In one embodiment, the central core of the combined flow is directed to the torch and the peripheral portion of the combined flow is ducted to waste. In another embodiment the aqueous spray solvent is fully evaporated before it leaves the spray chamber, and the combined flow is directed through a membrane dryer before reaching the torch, to remove most of the water vapor from the flow and thus to reduce water vapor loading on the torch.
摘要:
A device for electrospray ionization comprises two gas sources, or an arc jet of gas, provide second and third flows, of a gas, and include heaters for heating the second and third flows. The second and third flows intersect with the first flow at a selected mixing region, to promote turbulent mixing of the first, second and third flows, the first, second and third directions being different from one another, and each of the second and third directions being selected to provide each of the second and third flows with a velocity component in the first direction and a velocity component towards the axis of the capillary tube, thereby to promote entrainment of the heated gas in the spray, with the heated gas acting to assist the evaporation of the droplets to release ions therefrom. At least some of the ions produced from the droplets are drawn through the orifice for analysis.
摘要:
A device for electrospray ionization comprises two gas sources, or an arc jet of gas, provide second and third flows, of a gas, and include heaters for heating the second and third flows. The second and third flows intersect with the first flow at a selected mixing region, to promote turbulent mixing of the first, second and third flows, the first, second and third directions being different from one another, and each of the second and third directions being selected to provide each of the second and third flows with a velocity component in the first direction and a velocity component towards the axis of the capillary tube, thereby to promote entrainment of the heated gas in the spray, with the heated gas acting to assist the evaporation of the droplets to release ions therefrom. At least some of the ions produced from the droplets are drawn through the orifice for analysis.