Abouhiat Fatima Zohra, Henríquez Camelia, El Yousfi Farida, Cerdà Víctor
Department of Chemistry, Faculty of Sciences, University Abdelmalek Essaadi, B.P. 2121 Mhannech II, 93002 Tétouan, Morocco; Department of Chemistry, University of the Balearic Islands, Carretera de Valldemossa km 7.5, 07122 Palma de Mallorca, Spain.
Centre for Nuclear Energy in Agriculture, University of São Paulo, Piracicaba, SP 13400-970, Brazil.
Talanta. 2017 May 1;166:405-411. doi: 10.1016/j.talanta.2015.12.005. Epub 2015 Dec 9.
The development of an automated kinetic-catalytic spectrophotometric method for cobalt determination is presented. The method is based on the catalytic effect of Co in the oxidation of hydroxybenzoic acid by HO in basic media. The method has been automated using a multisyringe flow injection system coupled to a monolithic flow conduit called chip (chip-MSFIA). All reagents and sample are simultaneously propelled into the chip to achieve an efficient mixing. The reaction product is monitored at 482nm. The reaction takes place very fast at room temperature, thus the fixed-time method is applied to quantify Co concentration in samples. Variables such as, reagents concentration, pH, flow rate and reaction time have been optimized to improve the selectivity and sensitivity of the proposed system. Under optimal conditions, Co may be determined in the range 0.02-10.00μgL achieving a limit of detection of 0.02μgL and an injection throughput of 68h. Relative standard deviations are below 3%. The method has been successfully applied to water samples and a pharmaceutical formulation. The accuracy of the method has been validated by add-recovery tests and satisfactory recoveries from 91% to 97% were obtained.
本文介绍了一种用于钴测定的自动动力学催化分光光度法的开发。该方法基于在碱性介质中钴对羟基苯甲酸被过氧化氢氧化的催化作用。该方法通过与一种称为芯片的整体式流动管道（芯片-多注射器流动注射分析，chip-MSFIA）耦合的多注射器流动注射系统实现了自动化。所有试剂和样品同时被推进到芯片中以实现高效混合。在482nm处监测反应产物。该反应在室温下进行得非常快，因此采用固定时间法来定量样品中的钴浓度。对试剂浓度、pH值、流速和反应时间等变量进行了优化，以提高所提出系统的选择性和灵敏度。在最佳条件下，钴的测定范围为0.02 - 10.00μg/L，检测限为0.02μg/L，进样通量为68次/小时。相对标准偏差低于3%。该方法已成功应用于水样和一种药物制剂。通过加标回收试验验证了该方法的准确性，回收率在91%至97%之间，结果令人满意。
