建立了流动注射(FI)在线编结反应器(KR)预富集与火焰原子吸收光谱(FAAS)联用测定水样中痕量镍的吸力洗脱方法。洗脱过程依靠蠕动泵的吸力而不是推力实现洗脱剂的输送,明显降低了被分析物在洗脱过程中的分散,提高了原子吸收信号峰值(A)和浓集系数(EF)。增加了样品溶液排空步骤,保证了每次实验的准确性和重复性。进样流速6.0 mL/min,进样时间60 s,测定水样中的镍,EF由传统洗脱法的4.9提高到9.8,检出限为3.1μg/L,测样频率为41 h-1,相对标准偏差(RSD,n=11)为2.2%,以体积分数0.01%的三乙醇胺(TEA)为掩蔽剂,在水样中的回收率为95.5%～97.8%。

A flow injection suction elution method on-line sorption and preconcentration system coupled to flame atomic absorption spectrometry(FAAS) was developed for the determination of trace Ni in water.During the elution procedure,the eluent was pumped into KR by the suction force.Thus,the dispersion of the analyte was decreased notably,and absorbance peak value and enrichment factor(EF) value were improved.Emptying step was added in order to insure the veracity and repeatability of the experiment.With 60 s(sample throughput of 41 h-1) of sampling at a flow rate of 6.0 mL/min,an EF of 9.8(higher than 4.9 achieved by conventional elution method) and a detection limit(3σ) of 3.1μg/L-1 were obtained.The precision(RSD,n=11) was 2.2% at 200 μg/L-1 level.When 0.1 ‰(v/v) triethannolamine was used as masking reagent,the recovery rate of Ni in water was from 95.5 %~97.8 %.