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.