Practicing chemistry used to mean designing new compounds or engineering ways of applying chemicals to research and industrial processes, with little regard to how these compounds affected the environment. No more. “Green chemistry” has become popular and even necessary, as academic researchers, pharmaceutical manufacturers, and chemical companies search for ways to reduce the environmental impact of their work, while reducing use of toxics, lowering energy usage, and reducing volumes of expensive chemicals. The work is getting recognition as a significant change in how chemistry is conducted. In fact, since 2000, two Nobel Prizes have been awarded for contributing to some aspect of “green chemistry.”
Analytical chemistry was initially slow to adopt some of the processes as part of this trend. But that’s changing, as chemical companies look for ways to reduce environmental impacts of certain processes, and find less toxic analytical solutions. Today, analytical chemistry may be the only way to determine the environmental friendliness of any chemical product, process or methods.
Analytical Chemistry’s Role
Organic chemists were originally leading the way in green chemistry, fresh from two Nobel Prizes that illustrated the power of metathesis and of reducing the production of enantiomer mirror image chemicals, opening the door to a wide range of possibilities in organic synthesis. But over the past 20 years, analytical chemists and engineers have been catching up. They’ve developed 12 Principles of Green Chemistry to establish guidelines for reducing toxic and environmental hazards, make processes more energy efficient and identify possible process hazards.
These principles were meant to apply to every specialty in chemistry and in engineering. But analytical chemistry plays a unique number of roles in the greening of the lab, plant, factory, and even the environment. One principle of green chemistry (Number 11—Real time analysis for pollution prevention) applies directly to analytical chemists, and underscores the need for analysis that is “performed in-line, online or at-line in a chemical plant.” Other principles that apply to analytical chemists include prevention of waste generation, safer solvents and auxiliaries, design for energy efficiency and safer chemistry to minimize the chances of accidents.
The Search for Environmental Contaminants
Analytical chemistry tools have become more sensitive at detecting very low levels of potential pollutants, including volatile organic compounds (VOCs), persistent organic pollutants (POPs), and other persistent chemicals like DDT or other pesticide residues. They also have become more adept at detecting these pollutants in traditionally challenging matrices, such as feces, blood, or contaminated water. These new, more sensitive capabilities were developed from more sensitive chromatography and extraction equipment, as well as better handling of mass spectrometry and analytical capabilities.
Making Extraction Less Hazardous
Solvents such as hexane, benzene and acetone were long the mainstay of sample extraction steps prior to purification, chromatography, and MS analysis. In fact, extraction solvents now comprise the bulk of waste in chemical analysis. Now, processes are adapting less dangerous chemicals — sometimes eliminating them entirely (SPME, TWISTER, solid state, ultrasonic, etc.) — reducing and often eliminating the volumes of solvents needed for extraction.
Making Manufacturing Less Dangerous, and Reducing Energy
Detection of possible toxic interactions early can prevent the leakage and damage to the environment of these chemicals, thanks to the analytical and sensitive detection technology brought by analytical chemistry. Analytical chemistry is also making it possible to evaluate new solvents and other chemicals that may be less toxic or dangerous than those currently used.
PAT On the Head for Safer Drugs, Final Products
Modern pharmaceutical manufacturers are under consumer pressure and regulatory influence by the FDA and others to determine that their final drug products are defect-free and that no process changes produced harmful byproducts (or somehow altered the final product itself). Process analytical technology (PAT) is evolving into a sophisticated system to detect changes in chemical composition of an active ingredient or excipients, or changes brought about by hydrolysis or shifts in pH.
Some Patches in the Green Landscape
Green chemistry has come a long way, but there are still areas in need of development:
John Warner, president and CTO of the Warner Babcock Institute for Green Chemistry, told the U.S. Congress recently that current training in chemistry does not include education on the impact of chemical synthesis on human or environmental health. Warner pointed out that scientists need to focus more on non-toxic, chemically benign formulations. In addition, chemists should be trained in toxicology but currently are not, said Adelina Voutchkova, a chemist at George Washington University in Washington, D.C.
Researching Replacement Chemicals
Research in green chemistry includes finding ways to develop chemicals that are derived from sustainable, particularly non-petroleum sources; finding alternatives to chemicals that are increasingly in short supply; finding alternatives to stoichiometric reactions; and, for analytical chemistry, developing new methods that reduce the environmental harm or hazard risk of analytical techniques. These include solvent replacement, but also involve more applications of capillary electrophoresis, nano-scale analytics, and miniaturization.
Green chemistry — and its partner, green engineering — have certainly arrived. For analytical chemists in a number of disciplines this trend presents a wide range of new opportunities for product and process development. For a conversation about how to fit your own lab for environmental sustainability, reach out.