Development of miniaturized extraction method used for GC-NCD screening of non-volatile nitroso compounds in malt
Abstract
The aim of this study was to develop a miniaturized extraction method for a fast screening of non-volatile nitroso compounds using gas chromatography with a nitroso specific chemiluminescence detection. According to a final methodology, the samples were prepared by extraction of grinded malt using a mixture of pyridine and acetonitrile in ratio 60:40 (v/v).
To enhance volatility of the determined analytes, the two-step derivatization using hexamethyldisalazane and N,O-bis(trimethylsilyl)trifluoroacetamide was used. The total volume of the sample was 200 mu l and the preparation time after optimization was 80 min.
The extraction method was connected to a classification method, which can divide chromatographic peaks into the groups of N-nitroso and C-nitroso compounds, and interfering substances. After application of the methods mentioned above to real malt samples, the specific chromatographic peaks of C-nitroso and N-nitroso compounds were selected.