Spectrophotometric determination method for residual chlorine in trap water

摘要

PURPOSE: A spectrophotometric determination method is provided to reduce error and achieve improved accuracy by adding orthotoluidine solution through droplets rather than using a pipet. CONSTITUTION: A spectrophotometric determination method comprises a first step of arranging 3 to 5 ml of test sample into a container; a second step of developing color of test sample by adding 3 to 7 droplets of orthotoluidine solution through the use of droplet reagent bottle which permits addition of droplets in the unit of 0.03 0.004g; a third step of measuring absorptivity of the color developed sample at the wavelength of 408 to 476mm by using a spectrophotometer; and a fourth step of converting the measured absorptivity into density by applying the measured absorptivity to a standard curve formula.