Abstract: In analytical chemistry laboratory instruction, the conventional formaldehyde method for determining nitrogen content in ammonium sulfate presents two significant drawbacks: formaldehyde’s toxicity poses safety concerns for student experiments, and visual endpoint determination using phenolphthalein indicator introduces observational errors. This study implements an innovative digital approach to address these limitations. The experimental setup incorporates a robotic arm-controlled burette system integrated with pH sensors for intelligent endpoint detection, with all procedures conducted within a fume hood. Results demonstrate the digital method’s superior precision, showing a relative standard deviation of 0.42% for nitrogen content determination and a confidence interval of 20.13% to 20.33% for the overall mean. Statistical analysis reveals significantly better precision compared to manual titration (p<0.05). This digital design demonstrates broad applicability for titration experiments and offers valuable implementation potential for chemistry education.

Key words: Titration analysis, Ammonium sulfate, Digital design, Formaldehyde method