Measurement of oil adulteration

Due to their high retail value, some edible oils are often blended wilfully with other more inexpensive vegetable oils. Two recent publications by Kim et al. and Krause et al. in international journals were able to demonstrate that Spinsolve 1H benchtop NMR spectroscopy is a possible cost-effective method for discriminating the authenticity of some vegetable oils.

Patchouli oils

Overlaid 60 MHz 1H‑NMR spectra of genuine patchouli oils spiked with 9 different adulterants at 20%.

The first study comes from a collaboration of the National Institute of Food and Drug Safety Evaluation and the Chung-Ang University in Korea and examines perilla oil, which is an important flavouring agent in East Asian cooking. The authors demonstrate how 43 MHz benchtop NMR spectroscopy can be used to detect adulteration with less expensive soybean oils.

A study performed by Wageningen University takes patchouli essential oil as a test case for quality control on essential oils. Visual inspection of the 60 MHz 1H NMR spectra allowed for easy detection of 14 out of 17 chosen adulterants. The spectra of 10 random essential oils differed not only strongly from patchouli essential oil but also from one another, suggesting that fingerprinting by low-field NMR is not limited to patchouli essential oil. Automated chemometric evaluation of NMR spectra was possible by similarity analysis. Due to advantages such as simplicity, rapidity, reproducibility, and ability to detect nonvolatile adulterants, 60 MHz 1H NMR is complimentary to GC‑MS for quality control of essential oils.

See a full list of Spinsolve publications.

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Bertram works as Senior Applications Engineer for Magritek in Wellington. He gained his PhD under the supervision of Paul Callaghan and has been working in the field of NMR technology for over 20 years. 117 Posts