SPE–ICP–AES法测定环境水样中Cr(Ⅲ)

Determination of Trace Cr(Ⅲ) in Environmental Water Samples by ICP–AES Combined with Solid Phase Extraction

建立固相萃取与电感耦合等离子体原子发射光谱法（ICP–AES） 测定环境水样中Cr（ Ⅲ ） 含量的方法.合成了功能化铁氧体磁性材料作为固相萃取剂,优化了固相萃取条件.当样品溶液的pH 值为2.5 时,固相萃取剂能在5 min内完成Cr（ Ⅲ ） 的富集.使用1 mol/L HNO3 在3 min 内即可解吸附分离Cr（ Ⅲ ）,饱和吸附容量为15.2 μg/mg,研究了共存离子的影响.Cr（ Ⅲ ） 含量在1～50 μg/L 范围内与发射光谱强度呈良好的线性关系,线性相关系数为0.999 9,检出限为0.09 μg/L,测定结果的相对标准偏差为2.2%（n=8）,回收率为97.7%～104.8%.该方法高效、快速,测定结果准确可靠,可用于测定环境水样品中的痕量Cr（ Ⅲ ）.

A method was established for determination of trace Cr(Ⅲ) in environmental water samples by using solid phase extraction(SPE) and inductively coupled plasma atomic emission spectrometry. Functional ferrite magnetic particles was synthesized and used as solid phase extractant, the conditions of SPE were optimized. The solid phase extraction agent could completed the Cr(Ⅲ) concentration with the sample solution of pH 2.5 within 5 min. Desorption separation of Cr(Ⅲ) was completed within 3 min by using 1 mol/L HNO3. The adsorption capacity of solid phase extractant was 15.2μg/mg. The content of Cr(Ⅲ) had good linear relationship with the intensity of emission spectrum in the range of 1-50μg/L, the linear correlation coefficient was 0.999 9, the detection limit was 0.09μg/L. The relative standard deviation of determination results was 2.2%(n=8). The recoveries ranged from 97.7% to 104.8%. The method can detect trace Cr(Ⅲ) in environmental water samples quickly,efficiently and accurately.