Dioxin and polychlorinated biphenyl analysis: automation and improvement of clean-up established by example of spices.
To analyze polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDDs/PCDFs) and polychlorinated biphenyls (PCBs) in spices by gas chromatography-mass spectrometry, a new clean-up method had to be developed owing to the high content of essential oils in the samples. A solid-phase extraction (SPE) column with activated silica endowed with sulfuric acid and sodium hydroxide was used. Under these conditions, clean-up was achieved using at least 5-7 g of pepper and even higher amounts of other spices. The automatized clean-up comprised three additional chromatographic steps after accelerated solvent extraction (ASE) followed by gel permeation: chromatography on a florisil SPE column, extract cleaning with the above-mentioned silica SPE column and chromatography with an activated charcoal column. On the basis of this automatized clean-up, a method that is more effective, rapid, simplified and economical than the available methods for PCDD/PCDF and PCB analysis is proposed. In model studies, the average recoveries for PCDDs/PCDFs ranged between 82.6% and 105.6% and for the PCBs between 71.3% and 113.3%.
Federal Research Center for Nutrition and Food, Kulmbach, Institute for Chemistry and Physics, Germany. silvia.kleinhenz@bfel.de
Silvia
S
Kleinhenz
Wolfgang
W
Jira
Karl-Heinz
KH
Schwind
D001322:Autoanalysis / Q000295:instrumentation / Q000379:methods; D002845:Chromatography / Q000295:instrumentation / Q000379:methods*; D004147:Dioxins / Q000032:analysis*; D005506:Food Contamination / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D007202:Indicators and Reagents; D009822:Oils, Volatile / Q000737:chemistry; D011078:Polychlorinated Biphenyls / Q000032:analysis*; D012997:Solvents; D017365:Spices / Q000032:analysis*
D004147:Dioxins; D007202:Indicators and Reagents; D009822:Oils, Volatile; D012997:Solvents; D011078:Polychlorinated Biphenyls