In this study

a gas chromatography-mass spectrometry(GC-MS) was developed for the simultaneous detection of 13 kinds of organophosphate esters(OPEs) in greenhouse soil

including triethyl phosphate

tripropyl phosphate

tri-n-butyl phosphate

triisobutyl phosphate

tributoxyethyl phosphate

tris(2-ethylhexyl) phosphate

tris(2-chloroethyl) phosphate

tris(1-chloro-2-propyl) phosphate

Tris(1

3-dichloro-2-propyl) phosphate

triphenyl phosphate

tricresyl phosphate

toluene diphenyl phosphate and 2-ethylhexyl diphenyl phosphate.The experimental parameters such as extraction solvents

extraction methods

extraction times

extraction column types and chromatographic conditions were optimized.The soil samples were ultrasonically extracted with n hexane-acetone(1∶1

by volume)

and then purified with a Florisil solid phase extraction column

followed by analysis of GC-MS in selected ion monitoring mode and quantitative analysis by internal standard method.Results showed that there were good linear relationships for 13 target compounds in the mass concentration range of 1-500 μg/L

with their correlation coefficients(r2) of 0.999 3-0.999 7.The limits of detection(LODs

S/N=3) and limits of quantitation(LOQs

S/N=10) were in the ranges of 0.04-2.31 μg/L and 0.13-7.69 μg/L

respectively.The soil spiked recoveries at three spiked levels of 1.0

10 and 50 μg/L ranged from 54.5% to 130%

with relative standard deviations(RSDs) of 1.7%-9.9%.This method was applied to the analysis of 41 soil samples from vegetable greenhouses in Beijing.Except for tripropyl phosphate

12 kinds of OPEs were detected in all samples

with the concentration range of 1.90-632 ng/g(dry weight

dw)

the mean value of 87.8 ng/g and the median value of 39.7 ng/g.Tributyloxyethyl phosphate is the most abundant OPEs

contributing about 20% of the total content of 12 kinds of organophosphate esters(∑12OPEs).This method is simple

rapid

sensitive and accurate

and could meet the demands for analysis of 13 OPEs in soil.