浊点萃取-热喷雾火焰炉原子吸收光谱法测定水样中痕量的铜(Ⅱ)

Cloud Point Extraction-Thermospray Flame Furnace Atomic Absorption Spectrometry for the Determination of Copper (Ⅱ) in Water Samples

研究了以二乙基二硫代氨基甲酸钠(DDTC)为络合剂、Triton X-100为表面活性剂的浊点萃取-热喷雾火焰炉原子吸收光谱法测定水样中铜的实验方法.考查了DDTC的浓度、溶液pH值、表面活性剂浓度、加热时间、水浴温度、NaCl浓度、干扰离子等实验条件对浊点萃取效率的影响.在最优的实验条件下,该方法的检出限为0.8 ng mL-1,相对标准偏差为4.7%,富集倍数为20.对自来水、河水和标准水样中的铜进行了测定,结果令人满意.

A sensitive method based on cloud point extraction（CPE） for separation coupled with thermospray flame furnace atomic absorption spectrometry was proposed for the determination of ultratrace copper in water samples.The analytical procedure involved the formation of analyte-entrapped surfactant micelles by mixing the analyte solution with an sodium diethyldithiocarbamate（DDTC） solution and a Triton X-100 solution.Some parameters that influenced extraction and determination were evaluated in detail,such as the concentration of sodium diethyldithiocarbamate（DDTC）,pH of samples,the concentration of Triton X-100 and NaCl,extraction time,as well as interferences.Under optimized conditions,an enrichment factor of 20 could be obtained,and the limit of detection was 0.8 ng mL-1.The relative standard deviation（RSD） for 5 replicate determinations of 50 ng mL-1 of Cu（II） was 4.7%.Finally,the proposed method was successfully applied to the determination of copper in tap water,river water and standard water samples