Monasterio Romina P, Wuilloud Rodolfo G
Laboratory of Environmental Research and Services of Mendoza (LISAMEN), (CCT-CONICET-Mendoza), Mendoza, Argentina.
Talanta. 2009 Oct 15;79(5):1484-8. doi: 10.1016/j.talanta.2009.06.020. Epub 2009 Jun 16.
An on-line retention and preconcentration system based on a sheep wool-packed microcolumn combined with flame atomic absorption spectrometry is proposed for trace level determination of Cd in wine. A chelating reagent 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol was immobilized onto the wool before retention of the analyte. Several factors influencing the preconcentration efficiency of Cd and his subsequent determination, such as pH, eluent type, sample and eluent flow rates, interfering effects, were studied. A preconcentration factor of 39 was obtained with only 20 mL of sample. The relative standard deviation for five determinations of 1 microg L(-1) Cd was 3.4%. The calibration graph was linear with a correlation coefficient of 0.998 at levels near the detection limit and up to at least 25 microg L(-1). The limit of detection was 37 ng L(-1). The accuracy of the proposed methodology was tested by comparison of the results with those obtained by electrothermal atomic absorption spectrometry analysis along with a recovery study. Finally, the method was employed for evaluating Cd levels in different wines including, blank, rose, and red.
提出了一种基于羊毛填充微柱与火焰原子吸收光谱联用的在线保留和预富集系统，用于葡萄酒中痕量镉的测定。在保留分析物之前，将螯合试剂2-(5-溴-2-吡啶偶氮)-5-二乙氨基苯酚固定在羊毛上。研究了影响镉预富集效率及其后续测定的几个因素，如pH值、洗脱液类型、样品和洗脱液流速、干扰效应等。仅用20 mL样品就获得了39的预富集因子。对1 μg L⁻¹镉进行五次测定的相对标准偏差为3.4%。校准曲线在接近检测限及至少高达25 μg L⁻¹的水平范围内呈线性，相关系数为0.998。检测限为37 ng L⁻¹。通过将结果与电热原子吸收光谱分析结果进行比较以及回收率研究，对所提出方法的准确性进行了测试。最后，该方法用于评估不同葡萄酒（包括空白、桃红和红葡萄酒）中的镉含量。
