盐酸羟胺-柠檬酸体系提取土壤中的游离氧化铁

Extraction of Free Iron Oxide from Soil by Hydroxylamine Hydrochloride Citric Acid System

对盐酸羟胺柠檬酸体系（９５℃水浴加热）提取土壤中游离氧化铁的实验条件进行了研究。在所选的实验条件下，该体系对土壤中游离氧化铁的提取能力与常用的连二亚硫酸钠柠檬酸钠重碳酸钠（ＤＣＢ法）体系相当，但避免了ＤＣＢ法中引入Ｎａ２Ｓ２Ｏ４给随后分离和测定造成的沉淀、基体效应等各种弊端。方法的精密度较好，ＲＳＤ（ｎ＝６）为２．５％～３．０％。

The experiment conditions of extraction of free iron oxide from soils by hydroxylamine hydrochloride citric acid system has been studied. The results show that the amount of free iron oxide extracted from soils by the system(1.0 g NH 2OH·HCl, 2.0 mL 0.6 mol/L citric acid, 3.0 mL 1.0 mol/L NaOH and 95℃ water bath 4 h) coincides with the amount by dithionite citrate bicarbonate(DCB) system with precision of 2.5%～3.0% RSD( n =6). The substitution of Na 2S 2O 4 by NH 2OH·HCl avoids adverse effect from decomposed Na 2S 2O 4.