凝固-漂浮分散液液微萃取富集-分光光度法测定水中亚硝酸根

Determination of Trace Nitrite in Water by Spectrophotometry with Dispersive Liquid-Liquid Microextraction Based on Solidification of Floating Organic Drop Enrichment

研究了凝固-漂浮分散液液微萃取（SFO-DLLME）-分光光度法测定水样中痕量亚硝酸根的方法。以1-十二醇为萃取剂,乙醇为分散剂进行分散液液微萃取,离心后通过冷冻凝固操作使漂浮的萃取剂和水相分离。最佳实验条件下,方法的线性范围为2.0-280μg/L（r=0.999 9）,检出限为0.34μg/L。方法已成功应用于环境水样分析,相对标准偏差在2.4%-3.3%,加标回收率在98.2%-102.4%。

A method for the determination of trace nitrite in aqueous samples by spectrophotometry with dispersive liquid-liquid microextraction based on solidification of floating organic （DLLME-SFO） was investigated. In the DLLME, 1-dodecanol and ethanol were selected as extractant and dispersive solvent, respectively. After centrifugation, the floated extraction solvent droplet was solidified in an ice bath and it could be easily removed from water phase. Under the optimum test conditions, the linear range of the method was 2.0280 μg/L （r=0. 999 9） with the detection limit of 0. 34 μg/L. The proposed method has been successfully applied to the determination of nitrite in water samples. The relative standard deviation （RSD） was 2.4-3.3% with 98. 2-102.4% recovery.