摘要
在pH=1-3条件下,利用乙酰氧肟酸为显色剂,与Fe^(3+)定量生成稳定的红褐色络合物。通过光谱扫描确定最大吸收波长为480 nm。通过单因素实验确定显色体系的最佳条件:酸度(0.15 mol/L硫酸1 mL)、显色剂用量(1%,2.5 mL)、显色时间(20 min)、显色温度(室温,介于15-35℃之间)。在此基础上绘制标准曲线,线性相关良好。确定检出限为0.3312 mg/L。对该方法进行了检验,证明方法精密度和准确度良好。一些常见金属离子Fe^(2+)、Na^(+)、K^(+)、Ca^(2+)、Mg^(2+)、Al^(3+)、Zn^(2+)、Ni^(2+)、Cu^(2+)、Mn^(2+)在30倍量时,对测定结果无显著干扰;但能产生色度的Cr^(6+)(Cr_(2)O_(7)^(2-))和浊度的Pb^(2+)在1倍少量时无干扰,在10倍以上时会干扰测定结果。同时考察了常见阴离子(Cl^(-)、SO_(4)^(2-)、NO_(3)^(-)、PO_(4)^(3-)、NO_(2)^(-))含量为30倍量时对测定结果无影响。最后研究了此显色体系对全铁的测量。确定使用双氧水为氧化剂用量为0.5 mL(0.3%)。将新方法与水质邻菲啰啉光度法进行对比试验,t检验证明,两种方法不存在显著性差异。本研究希望能为水质Fe^(3+)及全铁测量提供新的参考借鉴。
Under the condition of pH=1-3,the stable reddish-brown complex was formed quantitatively with Fe^(3+) by using acetoxyxamic acid as color developing agent.The maximum absorption wavelength was determined to be 480 nm by spectral scanning.The optimum conditions of color development system were determined by single factor experiment:acidity(0.15 mol/L sulfuric acid 1 mL),color development agent dosage(1 %,2.5 mL),color development time(20 min)and color development temperature(room temperature,Between 15 and 35 ℃).On this basis,the standard curve is drawn,and the linear correlation is good.The detection limit was determined to be 0.3312 mg/L.The method is tested and proved to have good precision and accuracy.Some common metals Fe^(2+),Na^(+),K^(+),Ca^(2+),Mg^(2+),Al^(3+),Zn^(2+),Ni^(2+),Cu^(2+),Mn^(2+) had no significant interference on the determination results when the amount was 30 times.However,Cr^(6+)(Cr_(2)O_(7)^(2-)),which can produce chroma,and Pb^(2+),which has turbidity,have no interference at 1 times the small amount,and will interfere with the measurement results at more than 10 times.At the same time,when the content of common anions(Cl^(-),SO_(4)^(2-),NO_(3)^(-),PO_(4)^(3-),NO_(2)^(-))is 30 times,it has no effect on the determination results.Finally,the measurement of total iron by this color developing system is studied.The amount of hydrogen peroxide used as oxidant was determined to be 0.5 mL(0.3 %).The comparison test between the new method and the water quality phenanthroline photometric method was carried out,and the T-test proved that there was no significant difference between the two methods.This study is expected to provide a new reference for water quality Fe^(3+) and total iron measurement.
作者
胡新华
HU Xin-hua(School of Ecology and Environment,Minxi Vocational and Technical College,Longyan 364021,China)
出处
《宜春学院学报》
2023年第12期25-30,共6页
Journal of Yichun University
