Eugenol is main chemical component of flos caryophylli dry bud from eugenia caryophyllata thunb.It has several biological roles

including sterilization function

antioxidation and narcotism.It has been widely used in food and medicine.The detection of eugenol is of considerable interests for food and pharmaceutical analysis.To date

a number of methods such as gas chromatography

gas chromatography/mass spectrometry

high-performance liquid chromatography

thin layer chromatography and spectrophotometry has been reported.However

former four methods required expensive instrumentation and tedious sample pretreatment and last method suffered from lower sensitivity.Therefore

it is necessary to explore new sensitive and simple method for the determination of eugenol.In this work

it was found that eugenol inhibited strongly the chemiluminescence of luminol-DMSO-NaOH system.On this basis

a novel flow injection method with inhibited chemiluminescent detection was developed.The optimal conditions for the detection of eugenol are as follows:6.0×10

-4

mol/L pH 8.00 luminol

0.5 mol/L DMSO

0.1 mol/L NaOH.The method is sensitive

fast

and simple

superior to all documented methods.It allows for the detection of eugenol in the range of 5×10

-9

～1×10

-6

g/mL with a detection limit of 2.97×10

-9

g/mL.The relative standard deviation is 1.63% for the determination of 5×10

-7

g/mL eugenol(

n

=11).The method has been successfully used to determine eugenol in traditional Chinese medicine ding erqi tie with the recoveries of 93.3%

9

8.3% and the results obtained by this method were comparable with that by gas chromatography.Finally

the CL spectra and UV-visible absorption spectra were studied and the CL inhibition mechanism has been proposed due to the competition of eugenol with luminol for O

2

·-

generated by DMSO-NaOH-O

2

system.