NMR is an
important and useful technique that is used in the pharmaceutical analysis. The
principle of NMR is the nucleus of an atom in a magnetic field and exposed to
electromagnetic radiation resonate at a specific frequency of that radiation.
That allows us to record a spectrum and obtain structural information about the
sample. NMR uses radio frequency radiation, and its nuclei have a specific
property. A Nuclei with an odd number of protons and or nuclei with an odd
number of neutrons have this property and called spin, only nuclei that have a
spin are detectable by NMR. The spin has a value that called (I) which can
either be integer or half integer. The nuclei with an odd number of protons and
odd number of electrons have integer spin for example, 2H=1,6Li=1,10B=3.
On the other hand, nuclei with an odd number of protons or odd number of
electrons have half integer spin such as, 13C=1/2, 1H=1/2,
43Ca=7/2.Without an external applied magnetic field, a nucleus with
a spin generate their magnetic field. When an external magnetic field(B0), is
present the nuclei align their spin either with or against the field of the
external magnet. There are several applications for NIR spectroscopy in the
area of routine control analysis, and it is useful to many industrial sectors,
such as the environmental, agricultural, petrochemical, clinical, and
pharmaceutical fields. For this practical, a qualitative assay is used to
positively identify unknown powders, and a quantitative assay is used to
confirm the quantity of active ingredient in metoprolol tartrate tablets.