中文摘要：

通过正交实验，从过硫酸钾质量、实验用水、氧化时间、消解程序以及过硫酸钾溶液保存5个方面来探讨环境水样总氮检测过程中空白值偏高问题．结果表明：过硫酸钾是关键因素；新鲜蒸馏水、去离子水同样满足检测要求；应严格按照国标方法消解，消解30min；过硫酸钾溶液最好现用现配，至多不超过4d．

英文摘要：

The problem of higher blank value while total nitrogen monitoring was probed by orthogonal test on the potassium persulphate quality, the experiment water, the oxidation time, the dispelling program, and the potassium persulphate solution conservation. The results showed： the potassium persulphate is the first factor, fresh distilled water and deionized water are equal to satisfying the monitor demand, the dispelling program should be accored to the international standard and the time is 30 miniters, the potassium persulphate solution should be compounede at the same dme best and can not exceed 4 days.