Objective:To establish an ultraviolet spectrophotometry method for determination of trace kryptofix 2.2.2 in 18F-fluorodeoxyglucose product.Method:A storage solution was prepared by adding properly benzaldehyde and lead nitrate to citric acid-NaOH buffer solution(pH = 6.4)

and ultralviolet absorbance curve of the solution was changed to platform at the wavelength of 250 nm nearby

and the absorbance value of this solution was 0.4Abs ~ 0.6Abs at 250 nm.Properly 18F-fluorodeoxyglucose product was added to storage solution

and the absorbance value of trace Pb(Ⅱ)-kryptofix 222 complex was detected by ultraviolet Spectrometry for quantitative determination of trace kryptofix 222.Results:The absorbance coefficient of complex was 1.6×104 L/(mol·cm) at 250 nm;the linear range of kryptofix 222 was 0.0μg/ml~10.0μg/ml

the limit ofkryptofix 222 was 0.0μg/ml~10.0μg/ml

the limit of quantification was 0.13μg/ml;the adding recovery was 97.2%～102.7%

with the average recovery of 99.7%;the relative standard deviation(RSD) was 2.4%(n=5).Conclusion:The method was specific

sensitive and suitable for determination of trace kryptofix 2.2.2 in 18F-fluorodeoxyglucose product.