顺序注射环定量光度法在线测定水中总铁

选用邻菲啰啉作为显色剂,采用顺序注射环定量(SIA)光度法,结合一整套系统的PLC程序,成功建立了测定水中总铁的新方法.实验过程中对各条件进行了优化,在最优条件下,体系的检测范围为0～10 mg/L,线性回归方程为A=0.0995c+0.0421(c:mg/L,n=8),相关系数r为0.999 6,方法检出限为0.02 mg/L,相对标准偏差(RSD)为2.3%(0.50 mg/L,n=11)和1.7%(2.00 mg/L,n=11),实际水样的加标回收率为97.1%～102.0%.

On-line solid-phase extraction using alizarin violet functionalized silica gel for determination of trace lead in environmental samples and wastewater by sequential injection spectrophotometry

Trace of Pb(Ⅱ) has been on-line separated and enriched from environmental samples and wastewater by using the self-made alizarin violet functionalized silica gel micro-column coupling with a sequential injection sampling technology. The determination is based on the color reaction of Pb(Ⅱ) with iodide and crystal violet to form an ionic association complex in the presence of polyvinyl alcohol and hydrochloric acid. The use of the microcolumn can prevent the interference of most familiar metal ions, and therefore improve the selectivity and sensitivity of this analytical technique. The proposed method was used for the determination of Pb(Ⅱ) in environmental samples and wastewater. No statistically significant difference was observed between the results determined by the present method and atomic absorption spectrometry.