氢氧化钠熔融-氟离子选择电极法测定土壤全氟含量的熔融条件研究

Research on the Determination Fusion Conditions in Determining Soil Perfluor with Sodium Hydroxide Liquation Ion Selective Electrode Method

采用氢氧化钠为土壤全氟测定熔融试剂,设置了氢氧化钠状态、试样与熔剂比例、称样量、熔融温度、熔融时间等熔融条件的单因子试验,按选择的熔融条件,采用氟离子选择电极法,利用GBW07418、GBW07420标准样品进行方法检验。试验表明,采用氢氧化钠熔融—氟离子选择电极法测定土壤全氟含量时,熔融剂氢氧化钠形态、试样与熔融剂比例、称样量、熔融温度、熔融时间对土壤全氟测定值均会产生影响。采用氢氧化钠溶液作为熔融剂、称样量0.5000g、试样与熔融剂比例1:8、熔融温度600℃、熔融时间30min的熔融条件,检测方法的精密度、准确度可达到检验要求。

Sodium hydroxide was adopted as the soil perfluor determination liquation reagent.Factorial experiment was designed,including such liquation conditions as the state of soidium hydroxide,ratio between test sample and flux,sampling weight,fusion temperature,and fusion time.Ion selective electrode method was used to conduct method test with GBW07418、GBW07420 standard samples.The experiment results show that when adopting soidium hydroxide fusion-ion selective electrode method to determing soil perfluor content,the determined soil perfluor value is likely to be influenced by such factors as the state of soidium hydroxide,ratio between test sample and flux,sampling weight,fusion temperature,and fusion time.The test method can meet the accuracy demand when adopting soidium hydroxide solution as the molten solvent,the sampling weight is 0.500 0 g,the ratio between test sample and flux is 1：8,the fusion temperature is at 600 ℃ and the fusion time lasts for 30 min.