Abstract: Objective To establish a method for the quantification of iohexol in serum by high performance liquid chromatography (HPLC) and to evaluate its application for iohexol plasma clearance in children. Methods Set up the chromatographic conditions of HPLC and validate the linearity of standard curve, precision, trueness, stability of samples and drug interference. Thirty-three chronic kidney disease (CKD) children were included and examined by 99mTc-DTPA plasma clearance and iohexol plasma clearance and evaluated by the updated Schwartz formula (eGFR). Using 99mTc-DTPA plasma clearance as reference, compare the agreement and accuracy of the GFR-Iohexol or eGFR with GFR-99mTc-DTPA. Results The method for determination of the serum iohexol concentration was established by HPLC. The standard curve showed a good linearity (R2 =0.9998). The relative standard deviation RSD% of intra-assay and inter-assay were lower than 5% and the recovery rate was more than 96%. Iohexol plasma clearance showed better agreement and accuracy with99mTc-DTPA plasma clearance than eGFR. Conclusion A stable method for the measurement of serum iohexol concentration by HPLC has been established. Iohexol plasma clearance in children for GFR determination was accurate and feasible.

Key words: High performance liquid chromatography (HPLC), Iohexol, Content determination, Children