ABSTRACT
@#Objective To develop and verify a high performance liquid chromatography(HPLC) method for the determination of ethylenediaminetetraacetic acid disodium salt(EDTA-2Na) residues in the bulk of NMM tumor DNA vaccine for the quality control of DNA vaccine.Methods After NMM tumor DNA vaccine bulk was complexed with copper sulfate,a HPLC method for the determination of EDTA-2Na residues was developed with Agilent ZORBA XSB-C18(150 mm × 4.6 mm,5 μm) as the chromatographic column,water,tetrabutylammonium hydroxide 10% and acetonitrile solution(74.5:0.5:25)as the mobile phase.The detection method was as follows:the detection wavelength was 254 nm,the flow rate was 0.8 mL/min,the column temperature was 20 ℃ and the injection volume was 20 μL.The method was verified for the specificity,linear range,limit of detection(LOD),limit of quantification(LOQ),solution stability,durability,accuracy and precision,and used to detect the EDTA-2Na residues in several batches of DNA vaccine bulk.Results When EDTA-2Na control and DNA vaccine bulk with EDTA-2Na reacted with copper sulfate,the absorption peak appeared at around 5.3 min,while no absorption peak was observed when DNA vaccine bulk reacted with copper sulfate;In the range of 4～400 μg/mL,the control solution concentration showed a good linear relationship with the peak area,R~2=0.999 9;The LOD of the method was 10 ng/mL,and the LOQ was 40 ng/mL;The solution of control and sample was stable after placed for 12 h;When the detection conditions changed slightly(different mobile phase ratio,flow rate and column temperature),the influence on the detection results was within acceptable range;The average recovery rate of EDTA-2Na in low,medium and high concentration standard added samples was 101.38% with the RSD of 0.39%;0.1 mg/mL control solution was injected continuously for 6 times,and the peak area RSD was 0.04%.EDTA-2Na was not detected in 6 sample solution,and the peak area RSD of DNA vaccine bulk with EDTA-2Na solution was 0.02%,indicating a good intermediate precision.EDTA-2Na residue was not detected in these batches of DNA vaccine bulk.Conclusion The developed method is simple,accurate,reliable with good specificity,which can be used for the determi-nation of EDTA-2Na residues in DNA vaccine bulk.