Objective To improve and optimize the national standard GB/T 5750.4—2006,testing methods for anionic synthetic detergents,to improve examination efficiency.Methods Change the multi-step extraction to a single centrifugal extraction: quantitatively adding extracts and solvents(chloroform and methylene blue) at one-time and shaking strongly;after high-speed centrifuging,the absorbance of the extract in the chloroform layer was measured at 650nm by ultraviolet spectrophotometry.Results The calibration curves were linear in the range of 0-1mg/L for sodium dodecylbenzene sulfonate(SDBS;r= 0.999 9).The average recovery was 100.8%(n=9,RSD=2.1%);No statistically significant difference with the national standard method was observed.Conclusion The advantage of the optimized determination method was less amount of extraction solvent and shorter processing time.The method is simple,fast and accurate.It is reliable for the control of anionic synthetic detergent residues on tableware,and can greatly improve the efficiency of test.