海水悬浮颗粒物中不同形态磷的测定

分别采用硫酸过硫酸钾作为氧化剂进行高压消解和用浓度为1 mol/dm³盐酸浸泡提取,然后用磷钼蓝分光光度法测定海水悬浮颗粒物、沉积物中的总磷和无机磷,用差减法得到有机磷。悬浮颗粒物总磷(PTP)和无机磷(PIP)质量浓度分别为(632.4～651.7)×10^-6和(436.6～452.6)×10^-6时,其相对标准偏差小于1.44%。悬浮颗粒物总磷、无机磷和有机磷的回收率分别为97.2%～101.3%,97.8%～100.4%和97.3%～102.3%。所建立的分析方法可用于海水、河口水悬浮颗粒物及沉积物中不同形态磷的测定。

Determination of different forms of phosphorus in seawater suspended particulate matter

Suspended particulate matter in seawater was treated separately by high pressure digestion using sulfuric acid-potassium persulfate as the oxidant and soaking extraction in 1 mol/dm³ hydrochloric acid in order to dissolve total phosphorus and inorganic phosphorus respectively. The dissolved phosphorus was determined using phosphomolybdate blue spectrophotometry to calculate total and inorganic phosphorus in seawater suspended particulate matter and in sediments. Organic phosphorus was subsequently obtained by subtracting inorganic phosphorus from total phosphorus. The relative standard deviation was less than 1.44% when the concentration of PTP and PIP were (632.4～651.7)×10^－6 and (436.6～452.6)×10^－6 respectively. The recovery rate of PTP, PIP and POP were 97.2%～101.3%, 97.8%～100.4% and 97.3%～102.3% respectively. This analytical method can be used for determination of different forms of phosphorus in marine and estuarine sediment and in suspended particulate matter.