Patent ID: 8232500

Claim:
An inductively coupled plasma torch assembly comprising: a coolant tube comprising a coolant gas inlet end, a coolant gas outlet end and a collar bonded to or integrally formed with the coolant tube, said collar adjacent the coolant gas inlet end comprising a first tapered abutment surface; a plasma tube comprising a plasma gas inlet end and a plasma gas outlet end, disposed concentrically within the coolant tube; a sample tube disposed concentrically within the plasma tube; and a base for retaining the coolant and plasma tubes, having a top, a bottom and side defined with reference to the coolant and plasma tubes extending upward from the top of the base, the base comprising: a socket within which the plasma tube is fixed at the plasma gas inlet end thereof; a second tapered abutment surface in the top of base; and a passage through the base defined by a lumen for locating the sample tube concentrically within the plasma tube; and wherein the first tapered abutment surface of the collar and the second tapered abutment surface of the base have complementary tapers which cooperate to locate the coolant tube concentrically about the plasma tube; and wherein the inductively coupled plasma torch assembly further comprises interlocking portions which co-act to urge the first and second abutment surfaces together, said interlocking portions comprising a base interlocking portion on the top side of the base and a coolant tube interlocking portion which is either (a) part of the collar, or (b) provided by an annular member rotatable about the coolant tube on a side of the collar remote from the base and adapted to engage the remote side of the collar and urge the collar onto the base.