Oily seed extracts were used as research samples in Analytical Laboratory of Raw Materials and Plant Products. Supercritical carbon dioxide extraction on an industrial scale was used to prepare extracts from raw plant materials, usually berry seeds: blackcurrant, raspberry, strawberry, and chokeberry. Gas chromatography analysis was performed on Agilent equipment with single quadrupole mass spectrometer detector and split/splitless injector. Fatty acids (FAs) were determined using indirect method, where they were converted to c o r r e s p o n d i n g m e t h y l e s t e r s ( FA M E s ) d u r i n g trimethylsulfonium hydroxide solution reaction. Comparing the mass spectrum and retention time peak, more than 30 compounds in different oily extracts were qualitatively identified. Quantification of individual fatty acids was based on two different methods. Firstly, it was based on the received peak area, and the results were normalized without correction factor. Secondly, the quantification was based on external calibration curve, for 34 identified fatty acids. The method was validated, and the results, e.g., linearity, precision, limit of detection (LOD), and limit of quantification (LOQ), were presented.
In this study a multi-residue determination method for 36 pesticides in dried hops was reported. The sample preparation procedure was based on the acetate buffered QuEChERS method. A few mixtures of dispersive solid phase extraction (dSPE) sorbents consisting PSA, C18, GCB, Z-Sep and Z-Sep+ were investigated to clean-up the supernatant and minimize matrix co-extractives. The degree of clean-up was assessed by gravimetric measurements, which showed the best results for mixtures containing the Z-Sep+ sorbent. This is the first study to apply Z-Sep+ sorbent for hops material and the first to improve the method for pesticide residues determination in hops. Samples were analysed using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) and the procedure was validated according to the SANTE/11813/2017 document at four concentration levels: 0.02, 0.05, 0.1 and 1 mg/kg. The limits of quantification (LOQ) were in the range of 0.02–0.1 mg/kg. For all active substances, the trueness (recovery) ranged from 70 to 120% and the precision (RSDr) value was <20%. Specificity, linearity and matrix effect were also evaluated. The validated method was applied to the analysis of 15 real dried hop samples and the relevant data on detected residues were included.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.