摘要
将浊点萃取与钨丝电热蒸发原子荧光光谱分析法联用,测定了水样中的As(Ⅲ)和As(Ⅴ).该法利用非离子表面活性剂Triton X-114的浊点现象,在pH为3时,As(Ⅲ)与吡咯烷二硫代氨基甲酸铵(APDC)络合形成疏水性螯合物被萃取到表面活性剂的富胶束相,从而实现富集并达到与As(Ⅴ)分离.测定As(Ⅴ)时则预先用Na2S2O3将其还原为As(Ⅲ)而测定总As,然后由差减法求得As(Ⅴ)的含量.本法对As(Ⅲ)的检出限(3σ)为0.9μg/L,富集倍数为29(取样10 mL),可用于水样中As(Ⅲ)和As(Ⅴ)的测定.
As（ Ⅲ ） and As（ Ⅴ ） in water samples were determined by tungsten coil electrothermal vaporization Ar/H2 flame-AFS after cloud point extraction （CPE）. The CPE method is based on the cloud point phenomenon of non-ionic surfactant when heated to a certain temperature called cloud point. After complexation with ammonium pyrrolidinedithiocarbamate （APDC） at pH 3, the formed As-PDC complex can be entrapped into the micelle rich-phase of the non-ionic surfactant Triton X-114, while As（ Ⅴ ） cannot complex with APDC at pH 3 thus cannot be extracted. The total amount of As was determined after reducing As（ Ⅴ ） to As （ Ⅲ ） with Na2S2O3 and the concentration of As（ Ⅴ ） was obtained by subtracting of As（ Ⅲ ） from the total As. Under the optimal experimental conditions, the detection limit （3σ） d 0.9 μg/L with an enrichment factor of 29 for As（ Ⅲ ） was achieved with a sample volume of 10 mL. The proposed method can be useful in, the determination of As（ Ⅲ ） and As（ Ⅴ ） in water samples.
出处
《四川大学学报（自然科学版）》
CAS
CSCD
北大核心
2007年第3期645-648,共4页
Journal of Sichuan University(Natural Science Edition)
基金
教育部新世纪优秀人才支持计划项目(NCET-04-0869)
关键词
砷
形态分析
浊点萃取
钨丝电热蒸发
原子荧光
arsenic, speciation, cloud point extraction, tungsten coil electrothermal vaporization, atomic fluorrescence
