Over the past fifty years nuclear magnetic resonance spectroscopy, commonly referred to as NMR, has become the preeminent technique for structure determination of organic compounds. With developments in both methodology and instrumentation in the past two decades, NMR has become one of the most powerful and versatile spectroscopic techniques for characterization and quantification. An increasing concern with the well being of individuals and life in general has led to initiatives for improvements in medicine and the world environment, and in these areas analytical chemistry has particularly vital roles to play. Where new drugs or materials with potential commercial value are synthesized, a complete chemical characterization may be required involving considerable analytical work. More than any other analytical method the NMR spectroscopy provides information about the chemical structure and the dynamics of organic molecules. NMR spectroscopy is by definition a quantitative spectroscopic tool because the intensity of a resonance line is directly proportional to the number of resonant nuclei (spins). This fact enables accurate and precise determinations of the amount of substance.