Optimization and validation of the analytical method for determination of hemp essential oil composition

Industrijska konoplja (Cannabis sativa L.) je znana predvsem zaradi psihoaktivne spojine delta-9-tetrahidrokanabinola (THC) in kanabidiola (CBD). Poleg omenjenih spojin je konoplja bogata tudi z drugimi zdravilnimi in koristnimi snovmi, ki se nahajajo v eteričnem olju. Med te sodijo terpeni. To so spojine, ki se nahajajo v zeliščih, sadju in zelenjavi in so odgovorni za njihov okus ter vonj. Področje raziskav terpenov je narastlo predvsem v zadnjem času zaradi njihovih pozitivnih učinkov na človeški organizem in njihovo uporabo v agronomiji. Kemotip konoplje opredeljuje sestavo njenih komponent, ki jo ugotovimo preko analize eteričnega olja konoplje. Na Inštitutu za hmeljarstvo in pivovarstvo Slovenije smo optimirali in validirali metodo za določanje sestave eteričnih olj konoplje, pri čemer smo uporabili referenčne metode Evropskega pivovarskega združenja (angl. European Brewery Convention, EBC). Eterično olje konoplje smo pridobili z destilacijo z vodno paro po Clevengerju in ga nato analizirali s plinsko kromatografijo, pri kateri smo uporabili plamensko ionizacijski detektor. Ker se v eteričnem olju konoplje nahaja veliko število komponent, je validacija na vseh nemogoča. Zato smo validacijo metode izvedli na petih izbranih komponentah, ki smo jih izbrali glede na njihovo vsebnost v konoplji. V sklopu validacije smo določili selektivnost in specifičnost, linearnost, natančnost, točnost ter mejo zaznavnosti in mejo določljivosti. Ker smo pri validaciji uporabili starejše vzorce eteričnih olj, smo se dodatno odločili za preizkus stabilnosti eteričnega olja.Industrial hemp (Cannabis sativa L.) is mainly known for the psychoactive compound delta 9 tetrahydrocannabinol (THC) and cannabidiol (CBD). In addition to these compounds, hemp is also rich in other medicinal and beneficial substances, including terpenes. These are compounds found in herbs, fruits and vegetables and are responsible for their taste and smell. The field of terpene research has grown, especially in recent times due to their positive effects on the human body and their use in agronomy. The chemotype of cannabis is defined by the composition of its components, which is determined through the analysis of the cannabis essential oil. At the Slovenian Institute of Hops and Brewing, we optimised and validated a method for the determination of the composition of cannabis essential oils using the European Brewery Convention (EBC) reference methods. Cannabis essential oil was extracted by steam distillation with Clevenger apparatus and then analysed by gas chromatography using a flame ionisation detector. The large number of components in cannabis essential oil makes validation on all of them impossible. Therefore, the validation of the method was performed on five selected components, which were chosen according to their content in cannabis. As part of the validation, we determined selectivity and specificity, linearity, precision, accuracy, detection limit and limit of quantification. As the validation used older essential oil samples, we additionally decided to test the stability of the essential oil