海水悬浮物测定的影响因素分析及方法优化  

Method Optimization and Analysis of Influencing Factors for the Determination of Suspended Substance in Seawater

作　　者：张爽 王紫檀 姚文君[1] 赵仕兰[1] 张世杰 崔福旭 王燕[1] ZHANG Shuang;WANG Zitan;YAO Wenjun;ZHAO Shilan;ZHANG Shijie;CUI Fuxu;WANG Yan(State Environmental Protection Key Laboratory of Coastal Ecosystem,National Marine Environmental Monitoring Center,Dalian 116023,China;School of Environmental Science and Engineering,Dalian Maritime University,Dalian 116026,China)

机构地区：[1]国家海洋环境监测中心,国家环境保护近岸海域生态环境重点实验室,辽宁大连116023 [2]大连海事大学环境科学与工程学院,辽宁大连116026

出　　处：《中国环境监测》2024年第6期214-220,共7页Environmental Monitoring in China

摘　　要：对海水悬浮物(SS)分析中使用的滤膜材质和前处理方式、取样量、保存时间、烘干方式等进行优化,提出优化后SS的测定方法,并进行实际样品测试。结果表明:滤膜前处理可降低滤膜中可溶性物质在过滤过程中引起的误差,可选择纯水浸泡2 h后用500 mL超纯水过滤或纯水浸泡24 h 2种处理方式;综合考虑滤膜质量差和失重比例,醋酸纤维滤膜是SS测定的优质滤膜;当水体中SS浓度<10 mg/L、10 mg/L≤SS浓度<50 mg/L和50 mg/L≤SS浓度<100 mg/L,水样取样量分别不低于1000、750、500 mL时,平行样品的相对标准偏差小于2.5%;样品在4℃条件下10 d内基本保持稳定,相对标准偏差为0.12%~0.39%;滤膜烘干温度越高,所需重复烘干次数越少,100℃烘干2次可使滤膜达到恒重。实际样品比对结果发现,优化后的方法测定结果的准确度和精密度均明显高于标准方法。In this paper,the filter material,pretreatment method,sampling volume,storage time and drying method and other conditions in the determination of suspended substance(SS)in seawater were optimized,the method of SS determination after optimization was proposed,and the actual samples were tested.The results showed that soaking in pure water for 2 h and then filtering with 500 mL ultra-pure water or soaking in pure water for 24 h are suitable pretreatment method,which can reduce the error caused by soluble substances in the filter membrane during the filtration process.Considering the quality and weight loss ratio of the membrane,acetate fiber membrane is the optimal membrane for SS experiment.When the concentration of SS in seawater is less than 10 mg/L,10-50 mg/L and 50-100 mg/L,the minimum sampling volume of 1000,750 and 500 mL are suggested respectively with the relative standard deviation(RSD)of SS parallel sample less than 2.5%.Sample can remain stable during 10 days at 4℃refrigeration conditions with the RSD 0.12%-0.39%.The higher drying temperature,the less drying frequency required,the constant weight of the filter membrane can be reached by drying it twice at 100℃.Compared with standard method,higher accuracy and precision are acquired by optimized method which can significantly improve the accuracy of SS determination.

关 键 词：海水悬浮物 滤膜材质 滤膜前处理 取样量 烘干方式 

分 类 号：X834[环境科学与工程—环境工程]