Zougagh Mohammed, Rudner Pedro Cañada, de Torres Amparo García, Cano Pavón José M
Department of Analytical Chemistry, Faculty of Sciences, University of Málaga, Campus de Teatinos, 29071 Málaga, Spain.
Anal Bioanal Chem. 2004 Jan;378(2):423-8. doi: 10.1007/s00216-003-2213-6. Epub 2003 Sep 26.
This paper reports the development of a new methodology for the determination of cobalt in biological samples by using a flow injection system with loaded DPTH-gel as solid phase to preconcentrate analytes. The procedure is based on the on-line preconcentration of cobalt on a microcolumn of 1,5-bis(di-2-pyridyl)methylene thiocarbohydrazide immobilized on silica gel (DPTH-gel). The trapped cobalt is then eluted with 1% tartaric acid and 1% citric acid (7.1 mL) and determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). The analytical figures of merit for the determination of cobalt are as follows: detection limit (3S), 8.5 ng mL(-1); precision (RSD), 5.8% for 100 ng mL(-1) of cobalt; enrichment factor, 13 (using 7.3 mL of sample); sampling frequency, 40 h(-1) using a 60-s preconcentration time. For a 120-s preconcentration time (14.6 mL of sample volume) a detection limit of 5.7 ng mL(-1), an RSD under 5% at 50 ng mL(-1), an enrichment factor of 25, and a sampling frequency of 24 h(-1) were reported. The precision and accuracy of the method were checked by analysis of biological certified reference materials.
本文报道了一种新的生物样品中钴测定方法的开发，该方法使用装有DPTH-凝胶作为固相的流动注射系统对分析物进行预富集。该方法基于钴在固定于硅胶上的1,5-双（二-2-吡啶基）亚甲基硫代碳酰肼微柱（DPTH-凝胶）上的在线预富集。然后用1%酒石酸和1%柠檬酸（7.1 mL）洗脱捕获的钴，并用电感耦合等离子体原子发射光谱法（ICP-AES）进行测定。钴测定方法的分析性能指标如下：检测限（3S）为8.5 ng mL⁻¹；精密度（RSD），对于100 ng mL⁻¹的钴为5.8%；富集因子为13（使用7.3 mL样品）；采样频率，使用60 s预富集时间时为40 h⁻¹。对于120 s预富集时间（14.6 mL样品体积），报道的检测限为5.7 ng mL⁻¹，50 ng mL⁻¹时RSD低于5%，富集因子为25，采样频率为24 h⁻¹。通过分析生物认证参考物质对该方法的精密度和准确性进行了检验。
