Five tests every essential oil should go through for the highest quality. Ask your essential oil suppliers if they do these tests with their essential oils.
Test 1: Gas Chromatography
In gas chromatography, volatile essential oil compounds are vaporized and passed through a long column called a gas chromatograph. Each individual compound travels or “elutes” through the column at a different rate and is measured as it exits the column during the testing period. Using gas chromatography, quality control engineers can determine which compounds are present in a test sample and, as importantly, at what levels.
Test 2: Mass Spectrometry
In mass spectrometry, samples are vaporized and then ionized and each individual compound in a sample is measured by weight. Mass spectrometry provides additional insight to the purity of an essential oil by revealing the presence of non-aromatic compounds, such as heavy metals or other pollutants, which are too heavy to elute along a gas chromatograph. The combination of gas chromatography and mass spectrometry is sometimes referred to as a GC/MS test.
Test 3: FTIR Scan (Fourier Transform Infrared Spectroscopy) In an FTIR Scan, a light is shown at the material sample and the amount of light absorbed by the chemical constituents of the sample is measured. Results are then compared against a historical database to ensure adherence to composition standards.
Test 4: Microbial Testing
In microbial testing, samples are drawn from each batch of essential oils and applied to growing mediums in dishes or “plates.” After an incubation period, each plate is analyzed for growth of microbes. This test is performed on all incoming material to the manufacturing facility, and also performed on finished product to ensure no harmful organisms have been introduced to the product during the filling and labeling process, and to ensure shelf-life stability.
Test 5: Organoleptic Testing
Organoleptics include those attributes of an essential oil that can be tested with taste, sight, touch, and smell. From growers, and harvesters to essential oil chemists; from manufacturing engineers to essential oil practitioners. The extraction of essential oils is very much an art form that can be enhanced by, but not replaced with, mechanical analytics. The wisdom and experience of essential oil experts are an indispensable part of a great quality control standard.