涡旋辅助分散液-液微萃取-分光光度法 测定水中重金属Cr(Ⅵ)

Determination of heavy metal Cr(Ⅵ)in water by vortex-assisted dispersive liquid-liquid microextraction-spectrophotometry

利用二苯氨基脲显色以及超分子溶剂萃取,建立了一种涡旋辅助分散液-液微萃取—分光光度法测定水中Cr(Ⅵ)的方法(测定波长545 nm)。在以癸醇与四氢呋喃的摩尔比为1∶1制备的超分子溶剂为萃取剂、萃取剂用量为200μL(Cr(Ⅵ)溶液4 mL)、涡漩时间为2.0 min、氯化钠加入量为0.25 g/mL的最优萃取条件下,取得了较宽的线性范围(0.004~2.000μg/mL),检出限为0.15μg/L,定量限为0.45μg/L;加标回收实验的回收率为96.80%~103.50%,相对标准偏差为0.45%~2.50%。该方法具有操作简单、溶剂用量少、灵敏度高、精密度好、准确度高、萃取时间短的特点,可较好地满足水中Cr(Ⅵ)的测定要求。

A determination method of Cr(Ⅵ)in water was established by vortex assisted dispersive liquid-liquid microextraction-spectrophotometry(determination wavelength 545 nm)combined with diphenylaminourea coloration and supramolecular solvent extraction.Under the optimal conditions for using the supramolecular solvent with 1∶1 of the molar ratio of decanol to tetrahydrofuran as extraction reagent,extraction reagent amount 200μL for 4 mL of Cr(Ⅵ)solution,vortex time 2.0 min and sodium chloride amount 0.25 g/mL,a wide linear range of 0.004-2.000μg/mL,a detection limit of 0.15μg/L and a quantitative limit of 0.45μg/L are obtained.The recovery rate of the spike-and-recovery experiment is 96.80%-103.50%,and the relative standard deviation is 0.45%-2.50%.This method has the characteristics of simple operation,low solvent amount,high sensitivity,good precision,high accuracy and short extraction time,which can meet the requirements for determination of Cr(Ⅵ)in water.