The development of analytical instrumentation over the past 30–40 years has allowed us not only to detect trace metals at the parts per quadrillion (ppq) level, but also to know its valency state, biomolecular form, elemental species, and isotopic structure. We take for granted all of the powerful and automated analytical tools we have at our disposal to carry out trace elemental studies on clinical and environmental samples. Accurate analysis at trace levels, however, was not always so easy. As recently as the early 1960s, trace elemental determinations were predominantly carried out by traditional wet chemical methods such as volumetric, gravimetric, or colorimetric assays. It wasn’t until the development of atomic spectroscopic (AS) techniques, in the early to mid-1960s, that the clinical community realized that they had a highly sensitive and diverse trace element technique that could be automated. Every time there was a major development in AS, trace element detection capability, sample throughput, and automation dramatically improved (1). There is no question that developments and recent breakthroughs in atomic spectroscopy have directly affected our understanding of the way trace metals interact with the human body.