Laboratory of Foodomics, CIAL, CISC, Madrid, Spain.
Electrophoresis. 2012 Feb;33(4):705-12. doi: 10.1002/elps.201100272.
A fast and sensitive method for the simultaneous determination of Sudan dyes (I, II, III, and IV) in food samples was developed for the first time using partial filling micellar electrokinectic chromatography-mass spectrometry (MEKC-MS). The use of MEKC was essential to achieve the separation of these neutral analytes, while the partial filling technique was necessary to avoid the contamination of the ion source with non-volatile micelles. MEKC separation and MS detection conditions were optimized in order to achieve a fast, efficient, and sensitive separation of the four dyes. Filling 25% of the capillary with an MEKC solution containing 40 mM ammonium bicarbonate, 25 mM SDS, and 32.5% (v/v) acetonitrile, a baseline separation of the four azo-dyes was obtained in 10 min. Tandem MS was investigated in order to improve the sensitivity and selectivity of the analysis. Limits of detection (LOD) values 5, 8, 15, and 29 times better were obtained for Sudan III, I, II, and IV, respectively, using partial filling MEKC-MS/MS instead of partial filling MEKC-MS. Under optimized conditions, LOD from 0.05 to 0.2 μg/mL were obtained. The suitability of the developed method was demonstrated through the fast and sensitive determination of Sudan I, II, III, and IV in spiked chilli powder samples. This determination could not be achieved by MEKC-UV due to the existence of several interfering compounds from the matrix.
首次开发了一种使用部分填充胶束电动色谱-质谱联用（MEKC-MS）快速灵敏测定食品样品中苏丹染料（I、II、III 和 IV）的方法。使用 MEKC 对于实现这些中性分析物的分离至关重要，而部分填充技术对于避免离子源被非挥发性胶束污染是必要的。优化了 MEKC 分离和 MS 检测条件，以实现四种染料的快速、高效和灵敏分离。在毛细管中填充 25%的 MEKC 溶液，其中含有 40 mM 碳酸氢铵、25 mM SDS 和 32.5%（v/v）乙腈，可在 10 分钟内实现四种偶氮染料的基线分离。为了提高分析的灵敏度和选择性，研究了串联质谱。与部分填充 MEKC-MS 相比，使用部分填充 MEKC-MS/MS 分别获得苏丹红 III、I、II 和 IV 的检测限（LOD）值提高了 5、8、15 和 29 倍。在优化条件下，可获得 0.05 至 0.2μg/mL 的 LOD。通过快速灵敏地测定辣椒粉样品中的苏丹红 I、II、III 和 IV，证明了所开发方法的适用性。由于基质中存在几种干扰化合物，MEKC-UV 无法实现这种测定。
