Chemical characterization of essential oils (Chemotyping)
Nowadays, an external certification of natural products is a differentiation in a market saturated with chemotypes and with problems of “botanical transparency”.
Close monitoring of the chemical composition of an essential oil or a hydrosol is therefore necessary in order to have a natural product that maintains its bio-specificity and therefore complies with European and international standards and regulations.
Our knowledge and experience in the sector, together with our databases, built up over many years, are crucial to provide reliable results.
Sample treatment
Essential oils are processed without treatment, usually only diluted and ready for analysis. The analysis of hydrosols, absolutes and other extracts requires a prior step of separation of the aromatic fraction from the non-volatile phase, using extraction techniques such as HS-SPME. We also use these techniques to characterize essential oils present in complex matrices with non-volatile content, such as pharmaceuticals, phytosanitary products, nutritional supplements, etc.
On the other hand, if characterization of the plant material is required, we carry out steam distillation in the laboratory (clevenger) to obtain the essential oil and/or hydrosols and analyze it.
Qualitative analysis
The identification of each of the compounds in the oil is performed by gas chromatography (GC) coupled to a mass spectrometry (MS) detector. Each of the molecules is evaporated in an injection chamber and passes through a capillary column that assists in the initial separation by volatilization. Once in the detector, they are bombarded by an electron beam that ionizes and fragments them in a specific way depending on their chemical structure. Finally, the fragmentation pattern or fingerprint (mass spectra) and the time at which it reaches the detector (retention time) are compared with a library of spectra.
Quantitative analysis
At the exit of the column not all the flow ends up in the mass detector, but part of it goes to a flame ionization detector (FID) for quantification, since this offers greater linearity and repeatability than the mass detector. In industry this determination is usually performed by the internal standardization method, measuring the relative percentage of the mixture of substances, so it is not a true quantification method.
Our reports are based on this measurement, although we can also offer other quantification methods when required, as in the case of the characterization of absolutes or resinoids.
Two analyses for each service, highly automated
Each essential oil sample is injected into two different chromatographic columns, one with a polar stationary phase and the other with a non-polar stationary phase. In this way we obtain two molecular composition reports with a more accurate and complete result than with reference gas chromatography methods (ISO, pharmacopoeia, etc.).
A proprietary algorithm processes this data to provide a highly automated final report, which is still reviewed by our technical specialists, who import the results into our LIMS for final review and validation. Once signed, this report along with all source data is uploaded to the client platforms. The configuration of this report depends on the type of analysis and/or consultancy chosen, always providing the chemical family and cosmetic restrictions for each constituent of the essential oil.
