Purge and trap with monolithic sorbent for gas chromatographic analysis of pesticides in honey.
Polydivinylbenzene (P-DVB) and silica monolithic materials were synthesised in capillaries and then used to adsorb nine organonitrogen pesticides extracted from honey. After adsorption, each monolith-capillary was connected to a gas chromatograph (GC) with nitrogen-phosphorous detector (NPD). The silica monolith gave better peak shape and intensity than the P-DVB monolith. Formulation of silica monolith with tetramethoxysilane (TMOS) as a sole initiator provided better separation and higher peak intensity, compared to those with methyltrimethoxysilane (MTMS) and (3:1) TMOS/MTMS initiators. The optimum internal diameter and length of silica monolith-capillary were 0.25 mm and 5 cm, respectively. The purge and trap conditions were optimised by purging with nitrogen and heating the honey sample solution at 100 °C for 60 min. Recovery of the method was in a range of 84.95-99.71% and the detection limits of the pesticides determined by using GC-NPD and GC-mass spectrometric detector (MSD) ranged between 0.36-1.75 and 0.13-0.25 ng g(-1), respectively.
Department of Chemistry and the Center of Excellence for Innovation in Chemistry, Faculty of Science, Kasetsart University, Chatuchak, Bangkok, Thailand. fsciopc@ku.ac.th
Orapin
O
Chienthavorn
Kanittha
K
Dararuang
Anupop
A
Sasook
Narumol
N
Ramnut
D000327:Adsorption; D002849:Chromatography, Gas; D006722:Honey / Q000032:analysis*; D010575:Pesticides / Q000032:analysis*; D013343:Styrenes / Q000138:chemical synthesis / Q000737:chemistry*; D013499:Surface Properties
D010575:Pesticides; D013343:Styrenes; C056745:poly(divinylbenzene)