When using the Alder method to determine total sulfur in coal, attention should be paid to the following issues:

(1) Half melting must be carried out under ventilation, otherwise incomplete combustion of coal particles will prevent some sulfur from being converted into sulfur dioxide;

(2) The precipitant BaCl2 must be excessive;

(3) When extracting and washing with water, it is required that the solution volume should not be too large to avoid affecting the measurement results;

(4) Pay attention to adjusting the acidity of the solution to convert CO32- into CO2 and escape it;

(5) During the washing process, before each inhalation of distilled water, the washing solution should be filtered dry to achieve a better washing effect;

(6) Before burning, there should be no residual filter paper, and the high-temperature furnace should also be ventilated;

(7) After being burned, BaSO4 is cooled in a dryer and weighed in a timely manner;

(8) A blank test must be conducted.