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Principles of Instrumental Analysis, 6th ed. 9-22.

Chapter 9

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Skoog/Holler/Crouch Principles of Instrumental Analysis, 6th ed.

Chapter 9 Instructor’s Manual

CHAPTER 9
9-1. (a) A releasing agent is a cation that preferentially reacts with a species that would

otherwise react with the analyte to cause a chemical interference. (b) Protective agents prevent interference by forming stable and volatile products

with the analyte. (c) An ionization suppressor is more easily ionized than the analyte and provides a

high concentration of electrons in the flame or plasma. These electrons suppress the ionization of the analyte. (d) Atomization is the process by which a sample is vaporized and decomposed into

atoms usually by heat. (e) Pressure broadening refers to the broadening of atomic lines due to collisions with

other species. (f) A hollow-cathode lamp (Figure 9-11) has a tungsten anode and a cylindrical-

shaped cathode containing the element of interest. The element is sputtered from the cathode into the gas phase. This process excites some of the gaseous atoms, which then emit characteristic radiation as they return to the ground state. (g) Sputtering is the process in which gaseous cations bombard a cathode surface and

eject atoms from the surface into the gas phase. (h) Self-absorption refers to the absorption of emitted radiation by unexcited atoms in

the gas phase of a hollow-cathode lamp, flame, or plasma.

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Principles of Instrumental Analysis, 6th ed. (i)

Chapter 9

A spectral interference is encountered when the absorption or emission of a

nonanalyte species overlaps a line being used for the determination of the analyte. (j) A chemical interference is the result of any chemical process which decreases or

increases the absorption or emission of the analyte. (k) A radiation buffer is a substance added in excess to both sample and standards

which swamps the effect of the sample matrix on the analyte