分光光度法测定发样中的微量铁

建立了以邻二氮菲测定人发样中的微量铁的分光光度法。研究表明,在pH=2～9的溶液中,铁（Ⅲ）可用盐酸羟胺还原至铁（Ⅱ）,生成的铁（Ⅱ）可与邻二氮菲生成稳定的橘红色络合物,其最大吸收波长为506 nm,铁浓度在0.31～16.00 mg/L范围内与溶液吸光度呈良好线性关系,线性回归方程为A=0.20192ρ-0.01164（mg/L）,相关系数r=0.9999,检出限为0.157 mg/L,相对标准偏差（RSD）为0.58%,表观摩尔吸收系数ε=3.59×104L.（mol-1cm-1）。

Spectrophotometric Determination of Organic Matter in Soil with Potassium Dichromate

A spectrophotometric method was established to determine iron using 1,10-phenanthroline monohydrate(phen).With the presence of phen,Fe3+was reduced to Fe2+by hydroxylamine hydrochloride at pH 2~9,which facilitated the formation of orange product.The absorbance of orange product was measured at its absorption maximum of 506 nm,a good linear relationship was obtained in the range of 0.31~16.00 mg/L of iron.The linear regression equation was A=0.20192ρ-0.01164(mg/L) with a correlation coefficient of 0.9999 and the apparent molar absorption coefficient of 3.59×104 L/(mol·cm).The detection limit was 0.157mg/L,while R.S.D.was 0.58%.