A simple and sensitive method was developed for the determination of ethephon residues in cotton seed

cotton leaf and soil by solid phase extraction/ultrahigh performance liquid chromatography-tandem mass spectrometry(SPE/UPLC-MS/MS).The samples were extracted with methanol-01% formic acid

purified with an Oasis MAX column

and separated on a Cortecs Hilic column

finally analyzed in multiple reaction monitoring(MRM) mode via negative electrospray ionization(ESI-).Under the optimum condition

the calibration curves for the analyte were linear in the range of 0.02-1.94 mg/L

with correlation coefficients(r2) not less than 0.996 3.The limits of detection and quantitation for ethephon were 0.01 and 0.02 mg/kg

respectively.At spiked levels of 0.02

0.194 and 3.88 mg/kg

the recoveries for ethephon in three matrices were in the range of 78.3%-95.1% with relative standard deviations(RSDs) of 1.9%-5.2%.With the advantages of simplicity

high sensitivity

and good repeatability

the method could satisfy the requirements for determination of ethephon in cotton seed

cotton leaf and soil.