Analytical chemists develop methods and tools for detection and identification (qualitative analysis) and/or determination of the amounts (quantitative analysis) of the chemical constituents of a sample or system. Since science, in general, relies on quantitative measurements, it is appropriate that the discipline of chemistry have its own branch of specialists that are concerned with qualitative and quantitative measurements of chemicals. Analytical chemists are needed in wide-ranging industrial, government, and academic arenas, involving such things as environmental pollution evaluation and control, clinical chemistry, pharmaceutical development, synthetic chemistry, forensic analysis (e.g., drugs, explosives, and arson detection), and homeland defense (e.g., chemical and biological warfare agent detection), to name a few.