Purity
High Performance Liquid Chromatography is the method by which products are tested for purity. This method is utilized when there is a single molecule or class of molecules that can be assayed for. A solution containing the dissolved sample is introduced into the instrument where the individual components are separated and then analyzed.
NMR- Structural Information
Nuclear Magnetic Resonance spectroscopy is the method by which products are characterized for correct composition. This method is employed for single-molecule products for which structural information is desired. NMR takes advantage of the fact that nuclei in different environments relax at different rates when exposed to a magnetic field and yields extensive information about the nature of the bonds in the analyte.
TLC- Identification
Thin-Layer Chromatography is the method by which products are identified non-quantitatively. This method is used for plant extracts made up of many different compounds. TLC is essentially rudimentary 2-dimensional flash chromatography, except the mobile phase travels up the plate via capillary action instead of down the column.
ICP-MS- Heavy Metal Testing
Inductively Coupled Plasma with Mass Spectrometry is the method by which products are tested for metal contamination. All products undergo this test, specifically for arsenic, cadmium, mercury, and lead. ICP-MS uses an abundance of ions and their mass-to-charge ratio to quantify the presence of analytes.
Microbiology Panel - Contaminant Testing
The microbiology panel involves ensuring products are below acceptable limits for common and dangerous biological species. All products that are extracts of biological entities undergo this panel. The tests included in the panel are the Total Aerobic Plate Count, Yeast; Mold Count, E. Coli presence, S. Aureus presence, and Salmonella presence.
Some products are difficult or impossible to test via the aforementioned methods. In these cases, alternative methods must be used. Some of these methods are:
Gravimetry
Gravimetry is an alternative method by which products are assayed for purity. The object of gravimetric analysis is to manipulate the sample enough to the point where it can assayed by taking the mass of a solid.
UV
Ultraviolet-Visible Spectroscopy is another alternative method by with products are assayed for purity. A beam of light is passed through a solution containing the analyte, and the transmitted wavelengths and intensities are used to calculate the composition of the sample.
Titration
Titration is a third method by which products are assayed for purity. A known reagent is mixed with a solution containing the analyte, and the physical change that follows is interpreted by the chemist.