Simultaneous determination method of 10 organophosphate esters in oyster, an environmental indicator organism

Oyster is a common indicator organism of environment pollution. A method
was built to simultaneously determine ten common commercial
organophosphate ester flame retardants in oysters. After the careful
optimization of conditions, the organophosphate esters (OPEs) in oyster
sample were extracted with hexane assisted by ultrasound, purified with
NH2 solid-phase extraction column, eluted with the mixture solution of
dichloromethane and ethyl acetate at the ratio of 1:1 (v/v), and finally
detected by gas chromatography coupled with tandem triple quadrupole mass
spectrometry (GC–MS/MS). All the ten compounds in the concentrations
ranging from 0.5 ng·mL-1 to 100 ng·mL-1 showed good linearity with their
R2 higher than 0.9991. The limits of detection and limits of
quantification for the organophosphate esters were from 0.03 ng·g-1 to
0.47 ng·g-1 (dry weight) and from 0.1 ng·g-1 to 1.56 ng·g-1 (dry weight),
respectively. At the three spiking levels with five replicates, recoveries
of organophosphate esters ranged from 82% to 108% with the relative
standard deviation ranging from 0.9% to 6.4%. In the samples collected
from mariculture farms, nine OPE compounds were detected in oysters with
the concentration ranging from 6.52 ng·g-1 to 22 ng·g-1 (dry weight). It
indicated the method was suitable for OPEs determination in oysters.