Cassella Ricardo J, Magalhães Otto I B, Couto Marcos Tadeu, Lima Edson Luiz S, Neves Marcia Angélica F S, Coutinho Fernanda Margarida B
Departamento de Química Analítica, Universidade Federal Fluminense, Outeiro de São João Batista s/n, Centro-Niterói/RJ, 24020-007, Brazil.
Talanta. 2005 Jul 15;67(1):121-8. doi: 10.1016/j.talanta.2005.02.019. Epub 2005 Mar 20.
This paper reports the development of a new strategy for low-level determination of copper in water samples by using a flow-injection system coupled to solid-phase extraction (SPE) using flame atomic absorption spectrometry (F AAS) as detector. In order to preconcentrate copper from samples, a minicolumn packed with a styrene-divinylbenzene resin functionalized with (S)-2-[hydroxy-bis-(4-vinyl-phenyl)-methyl]-pyrrolidine-1-carboxylic acid ethyl ester was used and the synthesis procedure is described. System operation is based on the on-line retention of Cu(II) ions at pH 9.0+/-0.2 in a such minicolumn with posterior analyte elution with 2moll(-1) HCl directly to the F AAS nebulizer. The influence of several chemical (sample pH, buffer concentration, HCl eluent concentration and effect of the ionic strength) and flow (sample and eluent flow rates and preconcentration time) variables that could affect the performance of this system were investigated as well as the possible interferents. At optimized conditions, for 2min of preconcentration time (13.2ml of sample volume), the system achieved a detection limit of 1.1mugl(-1), a R.S.D. 1% at 20muggl(-1) and an analytical throughput of 25h(-1), whereas for 4min of preconcentration time (26.4ml of sample volume), a detection limit of 0.93mugl(-1), a R.S.D. 5.3% at 5mugl(-1) and a sampling frequency of 13h(-1) were reported.
本文报道了一种新策略的开发,该策略利用流动注射系统与固相萃取(SPE)联用,并以火焰原子吸收光谱法(F AAS)作为检测器,用于低水平测定水样中的铜。为了从样品中预富集铜,使用了一个微型柱,该微型柱填充有经(S)-2-[羟基-双-(4-乙烯基-苯基)-甲基]-吡咯烷-1-羧酸乙酯官能化的苯乙烯-二乙烯基苯树脂,并描述了合成过程。系统操作基于在pH 9.0±0.2条件下,将Cu(II)离子在线保留在这样的微型柱中,随后用2mol l⁻¹ HCl将分析物直接洗脱到F AAS雾化器中。研究了几个可能影响该系统性能的化学变量(样品pH值、缓冲液浓度、HCl洗脱液浓度和离子强度的影响)和流动变量(样品和洗脱液流速以及预富集时间)以及可能的干扰物。在优化条件下,预富集时间为2分钟(样品体积13.2毫升)时,该系统的检测限为1.1μg l⁻¹,在20μg l⁻¹时相对标准偏差为1%,分析通量为25 h⁻¹;而预富集时间为4分钟(样品体积26.4毫升)时,报道的检测限为0.93μg l⁻¹,在5μg l⁻¹时相对标准偏差为5.3%,采样频率为13 h⁻¹。