Department of Analytical Chemistry, Faculty of Sciences, University of Granada, Av. Fuentenueva s/n, E-18071 Granada, Spain.
Department of Analytical Chemistry, Faculty of Sciences, University of Granada, Av. Fuentenueva s/n, E-18071 Granada, Spain.
J Chromatogr A. 2018 Aug 10;1562:36-46. doi: 10.1016/j.chroma.2018.05.050. Epub 2018 May 28.
QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) methodology in combination with UHPLC-MS/MS is proposed for the determination of 5-nitroimidazole (5-NDZ) residues in infant milk-based products. Chromatographic separation was accomplished in a C18 Zorbax Eclipse Plus RRHD (50 × 2.1 mm, 1.8 μm) column under gradient elution conditions. Mobile phase consisted of 0.025% (v/v) aqueous formic acid (eluent A) and MeOH (eluent B), and was supplied at a flow rate of 0.5 mL/min. Under these conditions, eleven 5-NDZs including three metabolites were separated in less than 4 min. A novel QuEChERS method was optimized, and primary-secondary amine (PSA) sorbent was selected as clean-up agent. In addition, the proposed QuEChERS procedure was compared with other sample preparation methodologies, which are usually used in the analysis of 5-NDZs, namely solid phase extraction (SPE) using mixed cation exchange (MCX) cartridges and molecularly imprinted solid phase extraction (MISPE). Method comparison was carried out in terms of process efficiency, which includes matrix effect and extraction recovery. Higher process efficiency was generally achieved for QuEChERS and MISPE than for SPE. However, matrix effect was more significant for the non-selective QuEChERS method than for the selective MISPE. Higher extraction recoveries (63.2-94.1%) were observed for QuEChERS. The studied methods were validated in terms of linearity, detection limits (CCα), detection capabilities (CCβ) and precision, observing similar performance characteristics independently of the proposed sample treatment. CCα and CCβ ranged between 0.05 and 1.69 μg/L for all analytes and extraction techniques. QuEChERS-UHPLC-MS/MS method was also validated in terms of precision (relative standard deviations <10.3%), trueness (recovery>70.2%) and selectivity according to Regulation 2002/657/EC. It is proposed as a good alternative for the monitoring of 5-NDZ residues in enriched infant-milk based products and other similar milk based-products.
QuEChERS（快速、简便、廉价、有效、耐用和安全）方法与 UHPLC-MS/MS 结合，用于测定婴儿配方奶产品中的 5-硝基咪唑（5-NDZ）残留。在梯度洗脱条件下，在 C18 Zorbax Eclipse Plus RRHD（50×2.1mm，1.8μm）柱上完成色谱分离。流动相由 0.025%（v/v）甲酸水溶液（洗脱剂 A）和 MeOH（洗脱剂 B）组成，流速为 0.5mL/min。在这些条件下，11 种 5-NDZ 及其三种代谢物在不到 4 分钟内得到分离。优化了一种新的 QuEChERS 方法，并选择了伯仲胺（PSA）吸附剂作为净化剂。此外，还将所提出的 QuEChERS 程序与其他通常用于 5-NDZ 分析的样品制备方法进行了比较，即使用混合阳离子交换（MCX）小柱的固相萃取（SPE）和分子印迹固相萃取（MISPE）。方法比较是基于过程效率进行的，包括基质效应和提取回收率。QuEChERS 和 MISPE 的过程效率通常高于 SPE。然而，非选择性 QuEChERS 方法的基质效应比选择性 MISPE 更显著。QuEChERS 观察到更高的提取回收率（63.2-94.1%）。所研究的方法在线性、检测限（CCα）、检测能力（CCβ）和精密度方面均得到验证，观察到独立于所提出的样品处理，具有相似的性能特征。对于所有分析物和提取技术，CCα 和 CCβ 的范围为 0.05-1.69μg/L。QuEChERS-UHPLC-MS/MS 方法还根据 2002/657/EC 法规，在精密度（相对标准偏差<10.3%）、准确度（回收率>70.2%）和选择性方面进行了验证。它被提议作为监测富含婴儿配方奶的产品和其他类似奶基产品中 5-NDZ 残留的良好替代方法。
