印染废水中低含量阴离子洗涤剂的二次标准加入法测定

用次氯酸钠-亚硝酸钠-氨基磺酸铵颅处理,以消除染料对测定的干扰;采用二次标准加入法,并利用简单的迭代运算,求得被测液中阴离子洗涤剂含量。本方法对印染废水的测定上下限分别为6.0mg/L和0.75mg/L。经5个实验室对LAS含量为0.78mg/L和6.7mg/L的实际印染废水的协作试验验证,其重复性相对标准偏差分别为5.0和4.5％,再现性相对标准偏差为5.2和9.7％。

Determination of Anion-Surfactants in Dying Wastewater with Doubled Standard Addition Method

A pretreatment process with sodium hypochlo-rite-sodium nitrite-ammonium amino sulfonate was adopted to eliminate the interference from dye in the measurement of anion-surfactants in dye-containing wastewater. Doubled standard addition method and sumple repeated operation were used to determine anion-surfactant content in the examined solution. The upper and lower limit of the determination is 6.0 mg/L and 0.75 mg/L, respectively. Through a colaborative test and verification among fire laboratories on an actual dying waste-water containing LAS of 0.78 mg/L and 6.7 mg/L, it was determined that the repeatability standard deviation was 5.0 and 4.5 percent, and the repro-ducibility standard deviation was 5.2 and 9.7 percent, respectively.