ABSTRACT
This chapter looks at the major atomic spectroscopy (AS) techniques, compares their performance characteristics, and in particular examines the limit of quantitation for the four heavy metals (Pb, As, Cd, and Hg) currently being regulated in cannabis and hemp by most states in the United States. It also looks at the application requirements for the determination of the big four heavy metals in cannabis and cannabis products to offer some insight as to which might be the most suitable atomic spectroscopic approach. The chapter focuses on the most commonly used AS techniques—flame atomic absorption, electrothermal atomization, hydride generation atomic absorption, vapor generation atomic fluorescence, and inductively coupled plasma optical emission spectrometry. The elemental coverage limitations of the technique are similar to flame AA technique. However, because a heated graphite tube is used for atomization in most commercial instruments, it cannot determine the refractory, rare earth, and transuranic elements, because they tend to form stable carbides that cannot be readily atomized.
