Method Optimization and Analysis of Influencing Factors for the Determination of Suspended Substance in Seawater
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 1 000,750 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.
suspended substance in seawaterfilter materialpretreatment methodsampling volumedrying method
万方数据
维普
