【摘要】 采用F-选择电极法,对福建省酸性土壤有效F的提取方法进行了研究。3种浸提剂(去离子水、0.01 mol.L-1 CaCl2和0.01mol.L-1 HCl)中,只有去离子水提取的土壤有效F与茶叶含氟量呈显著正相关(r=0.392*,n=38)。对去离子水提取条件的研究表明,随液土比的升高,F提取总量升高,在适当提高F提取量又保证测定精度的前提下,将水提取有效F的液土比定为10∶1;振荡速度对F提取量有轻微影响,将振荡速度定为180 r.min-1;振荡时间从30 min增加到60 min,F提取量有所增加,随振荡时间的继续增加,F提取量反而降低,因而将振荡时间定为60 min;F提取量随浸提温度的升高而增加,为了使测定结果符合一般田间情况,将浸提温度定为25℃。更多还原

【Abstract】 The suitable extractant and corresponding extraction conditions for available F in acid soils collected from Fujian Province was studied with F-ion selective electrode.The de-ionized water was found to be the best among the three extractants(H2O,0.01 mol·L-1 CaCl2 and 0.01 mol·L-1 HCl),since the extracted F concentration using de-ionized water significantly correlated with the F content in tea leaves(r=0.392*,n=38).The total amount of water-extractable F increased but the concentration in the extracted solution decreased with the ratio of water to soil,so the ratio of water to soil for water extraction was set to be 10∶1.The total F amount extracted increased from 30 min to 60 min but decreased with longer shaking time,and the shaking time was fixed to be 60 min.The shaking velocity had slight effects on the extracted F from 120 r·min-1 to 240 r·min-1,so the extraction velocity was set to be 180 r·min-1.25 ℃,better conforming to field conditions,was selected as the extraction temperature although the extracted F amount increased with the extraction temperature from 20 ℃ to 45 ℃.更多还原