Comparison of gas chromatography-ion-trap tandem mass spectrometry systems for the determination of polychlorinated dibenzo-p-dioxins, dibenzofurans and dioxin-like polychlorinated biphenyls.
Two gas chromatography-mass spectrometry systems equipped with an ion-trap mass analyzer working in tandem mode (GC-MS-MS) were evaluated for the determination of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (PCBs) in food samples. The performance of the two ion-trap instruments, which dispose of an external ion source (ThermoFinnigan GCQ/Polaris) and internal ionization (Varian Saturn 2,200), have been compared in terms of linearity, repeatability, limit of detection and long-term precision. Both instruments provided similar run-to-run and day-to-day precisions, ranging from 2% to 8% and between 2% and 13%, and instrumental limits of detection between 0.09 and 0.36 pg injected for PCDD/Fs and from 0.03 to 0.09 pg injected for dioxin-like PCBs. Although both instruments seem to be suitable for food analysis, only the use of external ionization allowed to achieve reliable results for PCDD/F determination at concentrations close to the maximum residue levels established by the EU for foods. Internal ionization provides high limits of detection (from 10- to 30-fold higher) and worse precision (RSD, 14-43%). In contrast, for dioxin-like PCBs both instruments allowed to obtain excellent results with precisions lower than 15%.
Malavia
J
J
Analytical Chemistry Department, University of Barcelona, Martí i Franqués 1-11, 08028 Barcelona, Spain.
Santos
F J
FJ
Galceran
M T
MT
D000818:Animals; D001572:Benzofurans / Q000032:analysis* / Q000737:chemistry; D002645:Chickens; D002849:Chromatography, Gas / Q000379:methods* / Q000592:standards; D004147:Dioxins / Q000032:analysis* / Q000737:chemistry; D005395:Fish Oils / Q000737:chemistry; D005504:Food Analysis; D011078:Polychlorinated Biphenyls / Q000032:analysis* / Q000737:chemistry; D011786:Quality Control; D012996:Solutions; D053719:Tandem Mass Spectrometry / Q000379:methods*
D001572:Benzofurans; D004147:Dioxins; D005395:Fish Oils; D012996:Solutions; C023614:dibenzofuran; D011078:Polychlorinated Biphenyls; C020887:dibenzo(1,4)dioxin