取样量与烘干时间对总悬浮物测定结果的影响

就取样量和烘干时间两个因素的变化对总悬浮物测定结果的影响程度进行了探讨。结果表明 ,取样量是造成悬浮物测定结果准确与否的主要因素 ,而不同的烘干时间对测定结果的精密度不会造成明显的影响。随着取样量的逐步减少 (从 2 0 0 0 ml减至 50 ml) ,平行样的相对偏差则从 2 7%上升到 4 5 5%。为了使相对偏差≤ 1 5% ,取水量必须满足其中的总不可滤残渣达到 6 2 mg以上。

Effect of sampling volume and heat time on determination of total suspended solids

Based on determining samples of Fuzhou West Lake, this paper concluded the effect of sampling volume and heat time on determination of Total Suspended Solids (SS). The results indicate that sampling volume is an important fact of precision on SS determination. The length of heat time doesn't effect the result of SS determination. As the sampling volume declines (from 2000ml to 50ml), the relative SD of recoveries increases from 2.7% to 45.5%. To assure the relative SD no more than 15%, the sampling volume must meet the requirement that the residue is larger than 6.2 mg.