Universidade Federal da Paraíba, Departamento de Química, 58051-970 João Pessoa, PB, Brazil.
Universidade Federal da Paraíba, Departamento de Química, 58051-970 João Pessoa, PB, Brazil.
Talanta. 2018 Feb 1;178:384-391. doi: 10.1016/j.talanta.2017.09.063. Epub 2017 Sep 23.
A lab-made magnetic-mechanical robotic (MMR) system coupled to a flow-batch analyzer (FBA) for magnetic nanoparticles solid phase extraction (MSPE) is presented. As an illustrative application, an NMR-FBA couple was connected to a graphite furnace atomic absorption spectrometer (GFAAS) for quantification of trace cadmium in edible oils. Factors affecting MSPE, such as the amount of adsorbent, the type, concentration and volume of the eluent and elution time were studied. Under the optimized experimental conditions, the interferents studied did not reveal a significant change in the analytical response, indicating that proposed method is selective. The sampling rate, characteristic mass, working linear range, limits of detection (LOD), and sensitivity were 10h, 0.18pg, 0.05-1.0μgkg, 0.006μgL, and 0.4197, respectively. An enrichment factor of 9 was achieved using a 2.5mL oil sample. In order to evaluate the accuracy, a certified reference material was analyzed by the proposed and a reference method. The values obtained were compared with the one provided from the manufacturer and no statistically significant differences were observed among three values at a confidence level of 95% using paired t-test. In addition, the precision intra-day and inter day of the proposed method and the robustness were assessed and again no statistically significant differences were observed at a confidence level of 95%. The use of a microcolumn to immobilize the MNPs is not needed with the proposed MMR-FBA-GFAAS system, thus avoiding the well-known problem of non-uniform packing of the MNPs presented in previous flow-based automatic methods. Despite a high organic load of edible oils, the method developed is simple, robust and presents satisfactory analytical features when compared with others that have been reported in the literature, suggesting that it is a potentially useful alternative to determine trace analytes in viscous matrices without external pretreatment.
一种实验室制造的磁-机械机器人（MMR）系统与流动批次分析仪（FBA）耦合，用于磁性纳米颗粒固相萃取（MSPE）。作为一个说明性的应用，NMR-FBA 耦合与石墨炉原子吸收光谱仪（GFAAS）相连，用于定量测定食用油中的痕量镉。研究了影响 MSPE 的因素，如吸附剂的量、洗脱剂的类型、浓度和体积以及洗脱时间。在优化的实验条件下，研究的干扰物质对分析响应没有明显变化，表明该方法具有选择性。该方法的采样率、特征质量、工作线性范围、检测限（LOD）和灵敏度分别为 10h、0.18pg、0.05-1.0μgkg、0.006μgL 和 0.4197。使用 2.5mL 油样可实现 9 的富集因子。为了评估准确性，使用所提出的方法和参考方法对一种认证参考材料进行了分析。用配对 t 检验在 95%置信水平下比较了从制造商处获得的值与通过所提出的方法和参考方法获得的值之间没有统计学上的显著差异。此外，还评估了所提出方法的日内和日间精密度以及稳健性，在 95%置信水平下也没有观察到统计学上的显著差异。与以前的基于流动的自动方法相比，所提出的 MMR-FBA-GFAAS 系统不需要使用微柱固定 MNPs，从而避免了 MNPs 非均匀填充的已知问题。尽管食用油中的有机负荷很高，但与文献中报道的其他方法相比，该方法简单、稳健，具有令人满意的分析性能，表明它是一种在无需外部预处理的情况下测定粘性基质中痕量分析物的潜在有用方法。
