Abstract:

Because of the existence of chlorine ion, measuring the chemical oxygen consumption by bichromate tends to heighten the testing results. This article illustrates a new method of utilizing standard curve deduct ion. This method can quantitatively calculate the inaccuracy or errors caused by chlorine ion and measure the chemical oxygen consumption without chlorine ion-screening agent. Measuring the chemical oxygen consumption with this method, the s ranges from 2.135 mg/ L to 2.388mg/ L, the CV ranges from 4.6% to 0.3%, the recovery rate is 98.99%, within the National Standard concentration range ( 50～800 mg/ L).

Key words: chemical oxygen consumption, chlorine ion, standard curve

摘要：

重铬酸盐法测定化学需氧量受到氯离子的严重干扰，使结果偏高．采用标准曲线扣除法可定量地计算出氯离子的干扰，并在不加氯离子隐蔽剂的情况下测定化学需氧量，从而计算出无氯离子干扰时的化学需氧量．采用该法测定化学需氧量，在国标规定的质量浓度范围50～800mg/L内，其s为2.135～2.388mg/L，CV为4.6%～0.3%，回收率为98.99%．

关键词: 化学需氧量, 氯离子, 标准曲线

CLC Number: 

• X832