整体柱离子对色谱对铬(Ⅵ)的快速测定

Fast Determination of Cr(Ⅵ) by Ion-pair Chromatography Using a Monolithic Column

研究了基于硅胶整体柱的离子对色谱快速测定Cr(Ⅵ)的方法,讨论了淋洗液浓度、乙腈浓度、流速、温度和pH等因素对分离的影响。用1.0 mmol/L四丁基氢氧化铵-0.8 mmol/L邻苯二甲酸(pH6.0)作为淋洗液,流速6.0 mL/min,可以在1 min内快速分离测定Cl-、NO3-、Cr(Ⅵ)、SO42-离子。Cr(Ⅵ)的检出限为1.02 mg/L,保留时间和峰面积的相对标准偏差(RSD)(n=5)分别为0.2%和0.3%。将方法应用于测定地下水中的Cr(Ⅵ),回收率为104%。

An ion-pair chromatographic method for the determination of Cr（Ⅵ） has been developed using a silica-based monolithic column and a conductivity detector. The effects of eluent concentration, acetonitrile concentration, flow rate, temperature and pH on the separation of Cr （Ⅵ） were studied. By using 1.0 mmol/L tetrabutylammonium hydroxide （TBAH） -0. 8 mmol/L phthalic acid （pH 6.0） as the eluent with a flow rate of 6.0 mL/min, Cl^-, NO3^-, Cr（Ⅵ） and SO4^2- ions could be rapidly separated and determined in a minute. The detection limit for Cr（ Ⅵ ） was 1.02 mg/L and the relative standard deviations （n = 5 ） for the retention time and peak area were 0. 2% and 0. 3% , respectively. The method has been applied to the determination of Cr（ Ⅵ ） in groundwater with a recovery of 104% .