在线固相萃取预富集-原子吸收联用测定痕量Fe(Ⅱ)和总铁量

Determination of Iron(Ⅱ) and Total Iron Using Flow Injection On line Preconcentration With FAAS

以 1 ,1 0 -二氮菲 (1 ,1 0 -phen)为配合剂 ,乙醇为洗脱液 ,在 C1 8柱上将流动注射固相萃取预富集 -原子吸收光谱联用测定痕量 Fe( )和总铁 .Fe( )的含量可通过抗坏血酸还原后用差示法测得 .本法灵敏度高 ,选择性好 ,能在线分离干扰富集 Fe( ) ,采样速度 80次 / h,富集倍数 1 9倍 ,检测下限为 3μg/ L,相对标准偏差 1 .1 % (n=1 0 ) ,可用于测定水样中痕量 Fe( )和 Fe( ) ,回收率为 94 %～ 1 0 5%

A direct, rapid and sensitive method for the determination of Fe(Ⅱ) and Fe(Ⅲ) in water samples by flame absorption spectrometry coupled with flow injection on line preconcentration with 1,10 phenanthroline(\{1,10 phen\}) as the complex agent was developed. Various parameters affecting the complex formation and its subsequent adsorption, such as pH of the mixture solution, \{1,10 phen\} concentration, sample flow rate etc. were optimized. A 2 5×10 -3 mol/L 1,10 phen in 2 0% ethanol was on line mixed with aqueous sample solution of iron in 0 1%(volume ratio) hydrochloric acid and flowed through the microcolumn for 30 s. Fe(Ⅱ) can be extracted as Fe(Ⅱ) phen complex in the C 18 microcolumn and determined within 10 s in the nebulizer of FAAS after being eluted by ethanol. Ascorbic acid(0 1 mg/mL) was used for the reduction of Fe(Ⅲ) to Fe(Ⅱ). A good precision(RSD=1 1%, n =10), high enrichment factor(19) and sample throughput(80 h) with detection limit 3 μg/L were obtained. The method has been successfully applied on the water sample for Fe(Ⅱ) and Fe(Ⅲ) determination with the recovery 94%—105%.