Determination of 1,4-dichlorobenzene, naphthalene and thymol residues in honey using static headspace coupled with GC-MS
René Badertscher, Verena Kilchenmann , Agathe Liniger and Peter Gallmann
A simple, fast, sensitive and robust analytical method was developed for the simultaneous determination of 1,4-dichlorobenzene (p-DCB), naphthalene and thymol. The method is based on gas chromatography-mass spectrometry (GC/MS) coupled with a direct, static headspace (HS) injection. With 1-bromo-4-chlorobenzene (p-BCB) used as internal standard, quantification achieved a high sensitivity with a linear range in honey from 0.2 to 100 µgkg-1 for p-DCB, 0.5 to 100 µgkg-1 for naphthalene, and 3 to 1000 µgkg-1 for thymol with a correlation coefficient (r2) ranging from 0.9549 to 0.9884, respectively. The trueness was checked by repeated measurements of spiked honey samples on 3 concentration levels. There was no significant difference between the theoretical value and the obtained value. The mean Horwitz-Ratio (HORRATr with Thompson-correction) shows very good precision for p-DCB and naphthalene (0.5; 0.68) and good precision for thymol (1.23). The detection limits for p-DCB, naphthalene and thymol in honey were 0.04, 0.09 and 1.4 µgkg-1, respectively.