For example, synthetic rubber and plastics resulted from research on small molecules uniting to form large ones, a process called polymerization. They also spend time documenting and analyzing the results of their work and writing formal reports. Chemists also work in production and quality control in chemical manufacturing plants. They prepare instructions for plant workers which specify ingredients, mixing times, and temperatures for each stage in the process. They also monitor automated processes to ensure proper product yield, and they test samples of raw materials or finished products to ensure they meet industry and government standards, including the regulations governing pollution.
Chemists also record and report on test results, and improve existing or develop new test methods.
Chemists often specialize in a subfield. Analytical chemists determine the structure, composition, and nature of substances by examining and identifying the various elements or compounds that make up a substance. They study the relations and interactions of the parts and develop analytical techniques. They also identify the presence and concentration of chemical pollutants in air, water, and soil. Organic chemists study the chemistry of the vast number of carbon compounds which make up all living things.