The invention discloses a method for detecting the content of
methanol in
transformer insulation paper, and the method comprises the following steps of: S1, adding 1mL of to-be-detected
methanol into a 25mL colorimetric tube, sequentially transferring 2.5mL of a 25%
sulfuric acid solution and 0.5mL of a
potassium permanganate solution, uniformly shaking and standing the substances for 10min to obtain a first
mixed solution; S2, dropwise adding a
sodium sulfite solution into the first
mixed solution obtained in the S1 until the color just fades, then dropwise adding two drops of
chromotropic acid, uniformly mixing the substances, slowly transferring 6mL of concentrated
sulfuric acid along the wall of a colorimetric tube, and uniformly mixing the substances; S3, performing standing and cooling to
room temperature, adding water to dilute to a 25mL scale line, and uniformly mixing the substances to obtain a to-be-detected
mixed solution; and S4, measuring 3mL of the to-be-detected mixed solution, putting the solution into a 10*10mm
quartz cuvette, taking pure water as a reference solution, detecting the
absorbance of the mixed solution by using a
spectrograph, recording the spectrum of the mixed solution, and calculating the
methanol concentration. Based on the spectrum principle, the methanol concentration is obtained according to the relation between the methanol concentration and the characteristic
absorbance, the detection cost is reduced, and the detection accuracy is improved.