Organoleptic Assessments– What are the color, appearance, and aroma of the oil? By hand, the members of the essential oil chemist, quality technician, and manufacturing engineer [different] teams check these important indicators of the oil’s composition.
Gas Chromatography/Mass Spectroscopy (GC/MS) – A test where the sample undergoes a separation of constituents in the oil to see which compounds are presently giving a graphical representation of each molecule’s weight and chemical properties. This helps ensure that each sample is consistent with the chemical profile. After the Mass Spectroscopy is finished, then the oil’s constituents are then ionized, sent through magnetic fields, and checked for potency. Both of these tests help ensure that there are no contaminants in the oil.
Fourier Transform Infrared Spectroscopy (FTIR) - An infrared light shines through a sample of oil. That light travels to a mirror which reflects to a detector. This helps to validate the different frequencies of light absorption patterns compared with those of high-quality samples.
Optical Rotation or Chirality Testing – Testing the molecular structure by ensuring that there are no synthetic additives ruining the purity of the oil. Molecules produced in nature will produce mirror images of themselves. Often synthetically produced oil won't have the same distribution that nature produces. This test is essential for identifying synthetic additives.
Isotopic Testing – Each oil has certain elements that make up its composition. Due to the fact that essential oils are organic compounds, they make up certain isotopes (a stable existence of the same element to another.) These isotopic ratios vary from country to country, so ensuring the number of isotopes carries throughout the same location, helps the analyst see if there are adulterants or additives to the oil’s composition.
Contamination/Microbial Testing - Checking the oil for foreign contaminants goes a bit further as they inspect each oil through microscopes for total plate count, yeast, mold, salmonella, E. Coli and Pseudomonas (a type of bacteria.) Ensuring the oils are checked properly helps the buyer feel at ease.
Stability Testing – This test takes the oil through alternating humidity and temperature chambers, as well as different atmospheric conditions for extended periods of time. This helps to see that the oil is effective and safe for years to come.
Specific Gravity – This test verifies quality and purity by checking the volume-to-weight ratio to reference standards through the use of a Density Meter.
Refractive Index – Determining whether the refractive index or seeing how light spreads through the oil ensures that the standards have been met.
Heavy Metal Testing – Ionizing each sample after distillation is important for checking heavy metal amounts in the essential oil. Inductively Coupled Plasma, a very high-energy tool, ionizes the oil and then it is run through the Mass Spectroscopy to verify the constituents present and at what amount.