It is probably safe to say that most people not directly connected to our profession think that analytical chemists deal only with determinations of arsenic in wastewater or ozone in the atmosphere. Using instruments to determine analytes such as these at the parts-per-million level is considered the norm today, and we don´t even think twice when we read that the U.S. Environmental Protection Agency has established health standards for new chemicals found in drinking water. But sometimes I wonder if people think that meeting governmental regulations is all that defines analytical chemistry.

In conjunction with organic, inorganic, and physical chemistry, analytical chemistry is concerned with the identification, separation, and quantitative determination of the composition of different substances. But before the 1960s, analytical chemistry was mostly concerned with the identification of the structure of chemical species. Early commercial instruments such as proton NMR, electron impact mass, UV-visible, and infrared spectrometers analyzed neat or undiluted quantities of a chemical substance. Most instruments of this era were designed to produce data that determined chemical structure.

During the 1970s, analytical devices began to be used for quantitative determinations. Beginning in the 1960s with Rachael Carson´s Silent Spring and its condemnation of the indiscriminate use of chlorinated pesticides, the environmental movement showed that analytical instruments could be used to monitor toxic chemical levels in wastewater outfalls and smokestack plumes. However, to be meaningful for the protection of human health, it was necessary to make these determinations at ever lower detection levels. Whereas once we measured pollutants only at nanogram (10^–9 g) levels, now analytical chemists routinely measure analytes at picogram (10^–12 g) and even femtogram (10^–15 g) levels when necessary. In the 1950s, trace metal analyses were done with flame atomic absorption. The 1960s brought on graphite furnace technology, which allowed parts-per-billion analyses, and now there are inductively coupled plasma MS instruments that permit multilevel trace element determinations at parts-per-trillion levels.

The history of analytical chemistry is marked by the development of instruments capable of ever lower detection limits. Some of these advances developed because of the need for further monitoring of our environment. That´s why there are now EPA-approved ion chromatography methods for measuring chlorate and bromate levels in drinking water at the 10-ppb level and new atomic fluorescence technologies for the measurement of mercury at the parts-per-quadrillion level.

But other instrumentation advances have nothing to do with environmental regulations. There are single nucleotide polymorphism measurements in DNA that can only be made because of developments characterized as analytical chemistry. The same is true for new HPLC-MS technologies that allow researchers to identify and quantify proteins at the attomole (10^–18) level.

Analytical chemistry is performed wherever we need to make chemical measurements, be that in environmental analysis, genomics, proteomics, or any other chemical subspecialty. If history is anything to go by, the future of the instrumentation industry appears sound, for as new needs arise for more refined measurements, new devices will continue to be developed to meet those needs.