The invention relates to the field of 
tin-lead solder detection, and in particular relates to a method for the determination of 
tin content in 
tin-lead solder by 
complexometric titration method. The steps are as follows: a tin-lead solder specimen is weighed and placed in a triangular 
beaker; 8ml 
hydrochloric acid and 1-2ml 
nitric acid are added, the tin-lead solder specimen is heated and dissolved at low temperature, EDTA and water are added, the triangular 
beaker is placed on an electric furnace for heating to boil for 1 to 2 minutes to dissolve salts, the triangular 
beaker is taken down and cooled to 
room temperature; extensive 
ph indicator paper is added, 
hexamethylenetetramine solution is added for about six times until the extensive 
ph indicator paper just turns yellow, then excess 5 ml of the 
hexamethylenetetramine solution is added, two drops of 
xylenol orange indicator is added, a 
zinc standard solution is added for 
titration until the solution just turns red and does not fade; 
solid sodium trifluoride is added, the solution is shaken evenly and stood still for 5 minutes; and the 
zinc standard solution is added for 
titration until the solution just turns red and does not fade to reach the 
terminal point; the tin percent content can be calculated by the result analysis, the method for the determination of tin content in tin-lead solder by 
complexometric titration method is simple in operation, a tin reduction device is not needed, and the detection efficiency and accuracy can be improved.