Benson Co regularly assesses the quality of
essential oils & aromatic chemicals through
the evaluation of purity and identity.
We utilize physical or physiochemical techniques Using state of the art analytical instruments for
1. Gas Chromatography - Agilent GC 8860
2. Refractive Index, - RXA Anton parr
3. Specific Gravity - DMA 4500 M Anton parr
4. Optical Rotation - MCP 100 Anton parr
5. Melting point
6. Olfactory Evaluation – Focusing on Appearance and Odor.
Instrumental Testing: Gas Chromatography (GC)
Agilent GC 8860
A gas chromatograph (GC) is an analytical
instrument that measures the content of
various components in a sample. The analysis
performed by a gas chromatograph is called
Principle of gas chromatography : The sample solution injected into the instrument enters a gas stream which transports the sample into a separation tube known as the "column." (Helium or nitrogen is used as the so-called carrier gas.) The various components are separated inside the column. The detector measures the quantity of the components that exit the column. To measure a sample with an unknown concentration, a standard sample with known concentration is injected into the instrument. The standard sample peak retention time (appearance time) and area are compared to the test sample to calculate the concentration
Instrumental Testing : Refractive Index
RXA Anton parr
The measurement of refraction of light rays as they pass through material. This test is performed with the help of a Refractometer. A few drops of an sample under test are put between 2 prisms of the instrument at a known temperature and the index is measured. This testing thus requires very little sample and time; however, refractive index is only qualitative test for essential oils & aromatic chemicals
Instrumental Testing : Specific Gravity
DMA 4500 M Anton parr
Important in determining the quality of an
essential oil or aromatic chemical the technique
may be explained as the ratio of the weight of a
specific volume to the weight of an equal
volume of water at a defined temperature. The
specific gravity of water is 1.
In order to determine specific gravity of a sample, approximately 10 ml of sample is needed for analysis using an automated density meter, which determines the weight of the sample at a specific temperature. Specific gravity of the oil is inversely proportional to the temperature, therefore the temperature plays a critical role in this determination. Our instrument is capable of adjusting the pre-set temperature with an accuracy down to ± 0.01°C
Instrumental Testing: Optical Rotation
MCP 100 Anton parr
Whenever light rays pass through a transparent
material, in addition to refraction, rotation of
plane of polarization can also occur.
This is known as Optical Rotation and is defined
as a degree of angle of rotation.
This rotation can be to the left (levo rotatory / minus) or to the right (dextro rotatory / plus). The instrument used to determine optical rotation is called a polarimeter. It measures the degree of rotation by passing monochromatic light through the first of two polarizing plates, creating a polarized beam.
This beam is then rotated as it passes through the sample. After passing through the sample, a second polarizer (analyzer) rotates. When the analyzer is rotated such that all the light or no light can pass through, the angle of rotation is determined. Optical rotation, similarly to Refractive Index, is a qualitative measure of optical activity of oils & few aromatic chemicals
Olfactory Evaluation – Focusing on Appearance and Odor
The nose is one of the most efficient tools in essential oil sensory evaluation. A trained essential oil analyst can notice even small differences in odors and can immediately detect a quality problem with an oil before proceeding with more sophisticated analytical tests.
An essential oil can be rejected based on a poor or uncharacteristic odor profile. Although there are many advancements in the analytical techniques, organoleptic evaluation can still be the single most important arbiter of essential oil quality when a seasoned, trained essential oil chemist is taking the call