Abstract: An inductively coupled plasma torch (ICP) provides an efficient means for ermally degrading many organic molecules and exciting the resulting atomic species into optical emission. Spectrometric analysis produces reliable data for qualitative and quantiative simultaneous, multi-element analyses. To determine the empirical formula of a molecular compound, a gas chronometer is used to separate a mixture and atomic emission monitored continuously by a multi-channel spectrometer over the period of time required for the rise and fall of the elution. The plural channels provide parallel outputs defining intensity relationships or ratios of the excited elements. Instantaneous sampling repetitively made during the elution period provides a large number of discrete ratios that are averaged to provide the desired empirical formula. Molecular formulas then are derivable.

Abstract: Precise concentric alignment of the coolant, plasma and sample gas tubes d in conventional ICPs is an operationally important factor often achieved by fused arrangements which effectively preclude dismountability for maintenance and repair. Spacer rings slip-fitted into the coolant and plasma passages provide support for the concentric arrangement and also permit dismountability. Each ring is slotted to direct coolant and plasma gases and improve their intended functions. One ring spans the plasma tube and has a number of vertically-directed peripheral slots producing a laminar plasma gas flow. The other ring spans the coolant passage and has a pair of threads cut at spaced intervals to spiral the coolant gas and improve its heat transfer function. A separable base member supports the concentric lower ends of the tubes.